New IAC Wiki - User contributions [en]

Se Overview PrevMeas

2018-02-23T17:47:16Z

Starvale:

Selenium is an essential nutrient of fundamental importance to human biology. It is an essential constituent of more than two dozen selenoproteins that play critical roles in reproduction, thyroid hormone metabolism, DNA synthesis, and protection from oxidative damage and infection [1]. Thus the determination of selenium at trace and ultra-trace levels has become of increasing importance in life sciences [2–5]. The 82Se/76Se ratio remains relatively constant for ores, but in plants and soil varies from -1.2% to +0.2% [6]. The variations of 82Se/76Se ratio in plant material are believed to be a result of different bacteria residing in the plants. Since plants extract chemical elements directly from the soil during the growing phase, it is reasonable to expect that 82Se/76Se ratio in plants will reflect 82Se/76Se ratio in the soil. Thus the ratio of 82Se/76Se in the plants can be used to fingerprint the geographic region in which they were grown. In the past PAA was used to find a correlation between concentration of some trace elements in coffee and the soil it was grown in.

The concentration of trace elements nutritive importance and toxic effects in biological materials can be determined using different analytical techniques such as inductively coupled plasma mass spectrometry (ICP-MS), atomic absorption spectrometry (AAS), and RNAA [7, 8]. Unfortunately, they require a series of subsequent dissolution and chemical separation and thus have the inherent possibility of losing analytes or altering the contamination level.

PAA has been established for more than fifty years [9, 10], and became more commonly used by the 1980s, when high intensity photon sources became available [11]. Sample preparation for PAA is simple and for most of the samples chemical separation is not necessary. As a result, PAA developed into a relatively common tool for a variety of analytical problems, particularly where high sensitivity is required. Photon activation analysis of selenium has been done in the past using either 75Se or 81,81mSe radioisotopes. 75Se has a relatively long half-life of ~119 days, and requires long irradiation and long cooling time [12, 13]. Both 81Se and 81mSe are rather short-lived (T1/2 < 1 hour) and have also been used in PAA [14, 15]. The goal of this paper is to demonstrate that PAA can be an accurate tool to measure selenium concentration and the 82Se/76Se ratio in soil samples and find its detection limit.

References

1. Sunde RA (2012) Modern Nutrition in Health and Disease. Lippinkott Williams & Wilkins

2. Chajduk E, Polkowska-Motrenko H, Dybczyński RS (2008) A definitive RNAA method for determination of selenium in biological samples: uncertainty evaluation and assessment of degree of accuracy. Accredit Qual Assur 13:443–451.

3. Bakir MA, Yaseen T, Sarheel A, Othman I (2004) The determination of selenium concentration in blood and tumour tissues of breast cancer patients in Syria using instrumental neutron activation analysis. J Radioanal Nucl Chem 260:607–612.

4. Stosnach H (2010) Analytical determination of selenium in medical samples, staple food and dietary supplements by means of total reflection X-ray fluorescence spectroscopy. Spectrochim Acta Part B At Spectrosc 65:859–863.

5. Messaoudi M, Begaa S, Hamidatou L, Salhi M (2017) Determination of selenium in roasted beans coffee samples consumed in Algeria by radiochemical neutron activation analysis method. Radiochim Acta.

6. Krouse HR, Thode HG (1962) THERMODYNAMIC PROPERTIES AND GEOCHEMISTRY OF ISOTOPIC COMPOUNDS OF SELENIUM. Can J Chem 40:367–375.

7. Oleszczuk N, Castro JT, da Silva MM, et al (2007) Method development for the determination of manganese, cobalt and copper in green coffee comparing direct solid sampling electrothermal atomic absorption spectrometry and inductively coupled plasma optical emission spectrometry. Talanta 73:862–869.

8. Dybczyński RS, Danko B, Polkowska-Motrenko H, Samczyński Z (2007) RNAA in metrology: A highly accurate (definitive) method. Talanta 71:529–536.

9. Baker CA (1967) Gamma-activation analysis. A review. Analyst 92:601.

10. Lutz GJ (1971) Photon Activation Analysis -A Review. Anal Chem 43:93–103.

11. Starovoitova V, Segebade C (2016) High intensity photon sources for activation analysis. J Radioanal Nucl Chem 1–14.

12. Galatanu V, Engelmann C (1982) Analyse multielementaire des cheveux par photoactivation nucleaire. J Radioanal Chem 74:161–180.

13. Galatanu V, Engelmann C (1981) Determination de quelques elements traces dans le charbon, d’une maniere non destructive, par photoactivation nucleaire. J Radioanal Chem 67:143–163.

14. Chattopadhyay A, Jervis RE (1974) Multielement determination in market-garden soils by instrumental photon activation analysis. Anal Chem 46:1630–1639.

15. Jervis RE, Tiefenbach B, Chattopadhyay A (1977) Scalp hair as a monitor of population exposure to environmental pollutants. J Radioanal Chem 37:751–760.

[[PAA_Selenium#Can_one_perform_PAA_measurements_of_Se-82_and_Se-76.3F]]

[[PAA_Selenium#Can_one_perform_PAA_measurements_of_Se-82_and_Se-76.3F]]

Se Overview PrevMeas

2018-02-23T17:45:34Z

Starvale:

Selenium is an essential nutrient of fundamental importance to human biology. It is an essential constituent of more than two dozen selenoproteins that play critical roles in reproduction, thyroid hormone metabolism, DNA synthesis, and protection from oxidative damage and infection [1]. Thus the determination of selenium at trace and ultra-trace levels has become of increasing importance in life sciences [2–5]. The 82Se/76Se ratio remains relatively constant for ores, but in plants and soil varies from -1.2% to +0.2% [6]. The variations of 82Se/76Se ratio in plant material are believed to be a result of different bacteria residing in the plants.
The concentration of trace elements nutritive importance and toxic effects in biological materials can be determined using different analytical techniques such as inductively coupled plasma mass spectrometry (ICP-MS), atomic absorption spectrometry (AAS), and RNAA [7, 8]. Unfortunately, they require a series of subsequent dissolution and chemical separation and thus have the inherent possibility of losing analytes or altering the contamination level.

PAA has been established for more than fifty years [9, 10], and became more commonly used by the 1980s, when high intensity photon sources became available [11]. Sample preparation for PAA is simple and for most of the samples chemical separation is not necessary. As a result, PAA developed into a relatively common tool for a variety of analytical problems, particularly where high sensitivity is required. Photon activation analysis of selenium has been done in the past using either 75Se or 81,81mSe radioisotopes. 75Se has a relatively long half-life of ~119 days, and requires long irradiation and long cooling time [12, 13]. Both 81Se and 81mSe are rather short-lived (T1/2 < 1 hour) and have also been used in PAA [14, 15]. The goal of this paper is to demonstrate that PAA can be an accurate tool to measure selenium concentration and the 82Se/76Se ratio in soil samples and find its detection limit.

References

1. Sunde RA (2012) Modern Nutrition in Health and Disease. Lippinkott Williams & Wilkins

2. Chajduk E, Polkowska-Motrenko H, Dybczyński RS (2008) A definitive RNAA method for determination of selenium in biological samples: uncertainty evaluation and assessment of degree of accuracy. Accredit Qual Assur 13:443–451.

3. Bakir MA, Yaseen T, Sarheel A, Othman I (2004) The determination of selenium concentration in blood and tumour tissues of breast cancer patients in Syria using instrumental neutron activation analysis. J Radioanal Nucl Chem 260:607–612.

4. Stosnach H (2010) Analytical determination of selenium in medical samples, staple food and dietary supplements by means of total reflection X-ray fluorescence spectroscopy. Spectrochim Acta Part B At Spectrosc 65:859–863.

5. Messaoudi M, Begaa S, Hamidatou L, Salhi M (2017) Determination of selenium in roasted beans coffee samples consumed in Algeria by radiochemical neutron activation analysis method. Radiochim Acta.

6. Krouse HR, Thode HG (1962) THERMODYNAMIC PROPERTIES AND GEOCHEMISTRY OF ISOTOPIC COMPOUNDS OF SELENIUM. Can J Chem 40:367–375.

7. Oleszczuk N, Castro JT, da Silva MM, et al (2007) Method development for the determination of manganese, cobalt and copper in green coffee comparing direct solid sampling electrothermal atomic absorption spectrometry and inductively coupled plasma optical emission spectrometry. Talanta 73:862–869.

8. Dybczyński RS, Danko B, Polkowska-Motrenko H, Samczyński Z (2007) RNAA in metrology: A highly accurate (definitive) method. Talanta 71:529–536.

9. Baker CA (1967) Gamma-activation analysis. A review. Analyst 92:601.

10. Lutz GJ (1971) Photon Activation Analysis -A Review. Anal Chem 43:93–103.

11. Starovoitova V, Segebade C (2016) High intensity photon sources for activation analysis. J Radioanal Nucl Chem 1–14.

12. Galatanu V, Engelmann C (1982) Analyse multielementaire des cheveux par photoactivation nucleaire. J Radioanal Chem 74:161–180.

13. Galatanu V, Engelmann C (1981) Determination de quelques elements traces dans le charbon, d’une maniere non destructive, par photoactivation nucleaire. J Radioanal Chem 67:143–163.

14. Chattopadhyay A, Jervis RE (1974) Multielement determination in market-garden soils by instrumental photon activation analysis. Anal Chem 46:1630–1639.

15. Jervis RE, Tiefenbach B, Chattopadhyay A (1977) Scalp hair as a monitor of population exposure to environmental pollutants. J Radioanal Chem 37:751–760.

[[PAA_Selenium#Can_one_perform_PAA_measurements_of_Se-82_and_Se-76.3F]]

[[PAA_Selenium#Can_one_perform_PAA_measurements_of_Se-82_and_Se-76.3F]]

Se Overview PrevMeas

2018-02-23T17:44:53Z

Starvale:

Selenium is an essential nutrient of fundamental importance to human biology. It is an essential constituent of more than two dozen selenoproteins that play critical roles in reproduction, thyroid hormone metabolism, DNA synthesis, and protection from oxidative damage and infection [1]. Thus the determination of selenium at trace and ultra-trace levels has become of increasing importance in life sciences [2–5]. The 82Se/76Se ratio remains relatively constant for ores, but in plants and soil varies from -1.2% to +0.2% [6]. The variations of 82Se/76Se ratio in plant material are believed to be a result of different in the bacteria residing in the plants.
The concentration of trace elements nutritive importance and toxic effects in biological materials can be determined using different analytical techniques such as inductively coupled plasma mass spectrometry (ICP-MS), atomic absorption spectrometry (AAS), and RNAA [7, 8]. Unfortunately, they require a series of subsequent dissolution and chemical separation and thus have the inherent possibility of losing analytes or altering the contamination level.

PAA has been established for more than fifty years [9, 10], and became more commonly used by the 1980s, when high intensity photon sources became available [11]. Sample preparation for PAA is simple and for most of the samples chemical separation is not necessary. As a result, PAA developed into a relatively common tool for a variety of analytical problems, particularly where high sensitivity is required. Photon activation analysis of selenium has been done in the past using either 75Se or 81,81mSe radioisotopes. 75Se has a relatively long half-life of ~119 days, and requires long irradiation and long cooling time [12, 13]. Both 81Se and 81mSe are rather short-lived (T1/2 < 1 hour) and have also been used in PAA [14, 15]. The goal of this paper is to demonstrate that PAA can be an accurate tool to measure selenium concentration and the 82Se/76Se ratio in soil samples and find its detection limit.

References

1. Sunde RA (2012) Modern Nutrition in Health and Disease. Lippinkott Williams & Wilkins

2. Chajduk E, Polkowska-Motrenko H, Dybczyński RS (2008) A definitive RNAA method for determination of selenium in biological samples: uncertainty evaluation and assessment of degree of accuracy. Accredit Qual Assur 13:443–451.

3. Bakir MA, Yaseen T, Sarheel A, Othman I (2004) The determination of selenium concentration in blood and tumour tissues of breast cancer patients in Syria using instrumental neutron activation analysis. J Radioanal Nucl Chem 260:607–612.

4. Stosnach H (2010) Analytical determination of selenium in medical samples, staple food and dietary supplements by means of total reflection X-ray fluorescence spectroscopy. Spectrochim Acta Part B At Spectrosc 65:859–863.

5. Messaoudi M, Begaa S, Hamidatou L, Salhi M (2017) Determination of selenium in roasted beans coffee samples consumed in Algeria by radiochemical neutron activation analysis method. Radiochim Acta.

6. Krouse HR, Thode HG (1962) THERMODYNAMIC PROPERTIES AND GEOCHEMISTRY OF ISOTOPIC COMPOUNDS OF SELENIUM. Can J Chem 40:367–375.

7. Oleszczuk N, Castro JT, da Silva MM, et al (2007) Method development for the determination of manganese, cobalt and copper in green coffee comparing direct solid sampling electrothermal atomic absorption spectrometry and inductively coupled plasma optical emission spectrometry. Talanta 73:862–869.

8. Dybczyński RS, Danko B, Polkowska-Motrenko H, Samczyński Z (2007) RNAA in metrology: A highly accurate (definitive) method. Talanta 71:529–536.

9. Baker CA (1967) Gamma-activation analysis. A review. Analyst 92:601.

10. Lutz GJ (1971) Photon Activation Analysis -A Review. Anal Chem 43:93–103.

11. Starovoitova V, Segebade C (2016) High intensity photon sources for activation analysis. J Radioanal Nucl Chem 1–14.

12. Galatanu V, Engelmann C (1982) Analyse multielementaire des cheveux par photoactivation nucleaire. J Radioanal Chem 74:161–180.

13. Galatanu V, Engelmann C (1981) Determination de quelques elements traces dans le charbon, d’une maniere non destructive, par photoactivation nucleaire. J Radioanal Chem 67:143–163.

14. Chattopadhyay A, Jervis RE (1974) Multielement determination in market-garden soils by instrumental photon activation analysis. Anal Chem 46:1630–1639.

15. Jervis RE, Tiefenbach B, Chattopadhyay A (1977) Scalp hair as a monitor of population exposure to environmental pollutants. J Radioanal Chem 37:751–760.

[[PAA_Selenium#Can_one_perform_PAA_measurements_of_Se-82_and_Se-76.3F]]

[[PAA_Selenium#Can_one_perform_PAA_measurements_of_Se-82_and_Se-76.3F]]

Se Overview PrevMeas

2018-02-23T17:43:34Z

Starvale:

Selenium is an essential nutrient of fundamental importance to human biology. It is an essential constituent of more than two dozen selenoproteins that play critical roles in reproduction, thyroid hormone metabolism, DNA synthesis, and protection from oxidative damage and infection [1]. Thus the determination of selenium at trace and ultra-trace levels has become of increasing importance in life sciences [2–5]. The 82Se/76Se ratio remains relatively constant for ores, but in plants and soil varies from -1.2% to +0.2% [6]. The variations of 82Se/76Se ratio in plant material are believed to be a result of different in the bacteria residing in the plants.
The concentration of trace elements nutritive importance and toxic effects in biological materials can be determined using different analytical techniques such as inductively coupled plasma mass spectrometry (ICP-MS), atomic absorption spectrometry (AAS), and RNAA [7, 8]. Unfortunately, they require a series of subsequent dissolution and chemical separation and thus have the inherent possibility of losing analytes or altering the contamination level.

PAA has been established for more than fifty years [9, 10], and became more commonly used by the 1980s, when high intensity photon sources became available [11]. Sample preparation for PAA is simple and for most of the samples chemical separation is not necessary. As a result, PAA developed into a relatively common tool for a variety of analytical problems, particularly where high sensitivity is required. Photon activation analysis of selenium has been done in the past using either 75Se or 81,81mSe radioisotopes. 75Se has a relatively long half-life of ~119 days, and requires long irradiation and long cooling time [12, 13]. Both 81Se and 81mSe are rather short-lived (T1/2 < 1 hour) and have also been used in PAA [14, 15]. The goal of this paper is to demonstrate that PAA can be an accurate tool to measure selenium concentration and the 82Se/76Se ratio in soil samples and find its detection limit.

References

1. Sunde RA (2012) Modern Nutrition in Health and Disease. Lippinkott Williams & Wilkins
2. Chajduk E, Polkowska-Motrenko H, Dybczyński RS (2008) A definitive RNAA method for determination of selenium in biological samples: uncertainty evaluation and assessment of degree of accuracy. Accredit Qual Assur 13:443–451. doi: 10.1007/s00769-008-0377-7
3. Bakir MA, Yaseen T, Sarheel A, Othman I (2004) The determination of selenium concentration in blood and tumour tissues of breast cancer patients in Syria using instrumental neutron activation analysis. J Radioanal Nucl Chem 260:607–612. doi: 10.1023/B:JRNC.0000028220.00481.8e
4. Stosnach H (2010) Analytical determination of selenium in medical samples, staple food and dietary supplements by means of total reflection X-ray fluorescence spectroscopy. Spectrochim Acta Part B At Spectrosc 65:859–863. doi: 10.1016/J.SAB.2010.07.001
5. Messaoudi M, Begaa S, Hamidatou L, Salhi M (2017) Determination of selenium in roasted beans coffee samples consumed in Algeria by radiochemical neutron activation analysis method. Radiochim Acta. doi: https://doi.org/10.1515/ract-2017-2782
6. Krouse HR, Thode HG (1962) THERMODYNAMIC PROPERTIES AND GEOCHEMISTRY OF ISOTOPIC COMPOUNDS OF SELENIUM. Can J Chem 40:367–375. doi: 10.1139/v62-055
7. Oleszczuk N, Castro JT, da Silva MM, et al (2007) Method development for the determination of manganese, cobalt and copper in green coffee comparing direct solid sampling electrothermal atomic absorption spectrometry and inductively coupled plasma optical emission spectrometry. Talanta 73:862–869. doi: 10.1016/J.TALANTA.2007.05.005
8. Dybczyński RS, Danko B, Polkowska-Motrenko H, Samczyński Z (2007) RNAA in metrology: A highly accurate (definitive) method. Talanta 71:529–536. doi: 10.1016/J.TALANTA.2006.04.021
9. Baker CA (1967) Gamma-activation analysis. A review. Analyst 92:601. doi: 10.1039/an9679200601
10. Lutz GJ (1971) Photon Activation Analysis -A Review. Anal Chem 43:93–103.
11. Starovoitova V, Segebade C (2016) High intensity photon sources for activation analysis. J Radioanal Nucl Chem 1–14. doi: 10.1007/s10967-016-4899-x
12. Galatanu V, Engelmann C (1982) Analyse multielementaire des cheveux par photoactivation nucleaire. J Radioanal Chem 74:161–180. doi: 10.1007/BF02520369
13. Galatanu V, Engelmann C (1981) Determination de quelques elements traces dans le charbon, d’une maniere non destructive, par photoactivation nucleaire. J Radioanal Chem 67:143–163. doi: 10.1007/BF02516238
14. Chattopadhyay A, Jervis RE (1974) Multielement determination in market-garden soils by instrumental photon activation analysis. Anal Chem 46:1630–1639. doi: 10.1021/ac60348a059
15. Jervis RE, Tiefenbach B, Chattopadhyay A (1977) Scalp hair as a monitor of population exposure to environmental pollutants. J Radioanal Chem 37:751–760. doi: 10.1007/BF02519387

[[PAA_Selenium#Can_one_perform_PAA_measurements_of_Se-82_and_Se-76.3F]]

[[PAA_Selenium#Can_one_perform_PAA_measurements_of_Se-82_and_Se-76.3F]]

Se PAA Reactions

2018-02-23T16:57:39Z

Starvale:

[[PAA_Selenium#Can_one_perform_PAA_measurements_of_Se-82_and_Se-76.3F]]
==Single and double particle knockout reactions==

[[File:TableOfReactions.jpg|600px]]
==Neutron knockout of Se-82==
If you knock a neutron out of Se-82 you produce the unstable isotope Se-81 which Beta emitts with half life of 18.45 min and a meta-state that emmits a 103 keV gamma with a 57.28 minute half life.

<math>{82 \atop 34\; }Se (\gamma,n){81 \atop \; }Se</math>

Prominent decay photons from an IT are

276 keV and 290 keV for the 57 minute half life isotope, 566 & 828 have less than half the intensity of the 276 and 290

The minimum energy required to knock out a neutron from this isotope is

(Mass of Se-81)-(Mass of Se-82)+(Mass of 1 neutron)[MeV/c^2] = 73511.651 - 744442.2136 + 939.57 -> 9.0 MeV

you can see the line and half life in the root file /data/IAC/Se/Feb2017Run/Pure_Se_cat.root file on daq1 using the commands

MPA->Draw("-2.7285+0.815579*evt.Chan","evt.Chan>338 && evt.Chan < 344 && evt.ADCid==1");

MPA->Draw("evt.Sec/60","evt.Chan>338 && evt.Chan < 344 && evt.ADCid==1");

==Neutron knockout of Se-76==
If you knock a neutron out of Se-76 you produce the unstable isotope Se-75 which has a half life of 119 days.

<math>{76 \atop\; 34}Se (\gamma,n){75 \atop \; }Se</math>

The prominent photons emitted have the following energies in order of high to low intensity

136, 264, and 279 keV

http://www.nucleide.org/DDEP_WG/Nuclides/Se-75_tables.pdf

The article below describes how plant material and soil contain Se-76 to Se-82 ratios that differ from other natural samples by 1.5%. They argue that it is due to the bacteria living in plant material.

[[File:Krouse_CanJournChem_40_1962_p367.pdf]]

Plant material is a natural way to sample the selenium content to determine if there are difference isotopic ratios due to the impact of human activities on the environment.

The energy required to knock out a neutron from this isotope is

(Mass of Se-75) + (Mass of 1 neutron) - (Mass of Se-81)[MeV/c^2] = 69790.3321 + 939.57 - 70718.1 -> 11.8 MeV

==Relative Yield Calculations==
For this section, I am interested in finding the relative yield of Se-79 when compared to Se-81 and Se-75. Cross sections were found at this website: http://www-nds.indcentre.org.in/exfor/servlet/X4sSearch5?EntryID=220070

===Cross-section===

Below is a table of the cross sections for all of the reactions of interest (Se-76 -> Se-75, Se-82 -> Se-81, and Se-80 -> Se-79).

{| border="3" cellpadding="5" cellspacing="0"
||Energy (MeV) || Se-80 -> Se-79 (mb) || Se-76 -> Se- 75 (mb) || Se-82 -> Se-81 (mb)
|-
||9.42 || ** || ** || 5.58 +/- 0.5
|-
||9.62 || ** || ** || 8.7 +/- 0.5
|-
||9.82 || ** || ** || 10.8 +/- 0.5
|-
||10.02 || 7.1 +/- 0.2 || ** || 12.4 +/- 0.7
|-
||10.22 || 10.3 +/- 0.4 ||0.4 +/- 0.2 || 15 +/- 0.9
|-
||10.42 || 12.9 +/- 0.5 || 0.8 +/- 0.3 || 15.4 +/- 0.9
|-
||10.62 || 16.2 +/- 0.5 || 4.7 +/- 0.3 || 17.3 +/- 1.1
|-
||10.82 || 19.2 +/- 0.6 || 6.6 +/- 0.4 || 21 +/- 1.1
|-
||11.02 || 22 +/- 0.6 || 9.9 +/- 0.3 || 21.8 +/- 1.4
|-
||11.22 || 23.8 +/- 1 || 12.2 +/- 0.4 || 22.5 +/- 1.9
|-
||11.42 || 28 +/- 1 || 19.5 +/- 0.5 || 27.7 +/- 1.5
|-
||11.62 || 28.6 +/- 1.2 || 23.5 +/- 0.5 || 27.8 +/- 2
|-
||11.82 || 30.4 +/- 1.5 || 26.7 +/- 0.8 || 28.4 +/- 1.8
|-
||12.02 || 33 +/- 1.4 || 32 +/- 0.8 || 31.9 +/- 1.8
|-
||12.22 || 34.9 +/- 1.8 || 36.3 +/- 0.8 || 34.5 +/- 2.4
|-
||12.42 || 37.6 +/- 1.4 || 38.8 +/- 1.4 || 38.3 +/- 2.8
|-
||12.62 || 41.5 +/- 2 || 40.9 +/- 1.4 || 42.6 +/- 3
|-
||12.82 || 43.6 +/- 2.5 || 46.7 +/- 1.6 || 41 +/- 3.2
|-
||13.02 || 46.7 +/- 2.8 || 49.2 +/- 1.8 || 48.8 +/- 2.5
|-
||13.22 || 51.9 +/- 2.6 || 55.8 +/- 1.5 || 53.3 +/- 3.4
|-
||13.42 || 56.7 +/- 1.5 || 56 +/- 2.5 || 52.7 +/- 4.3
|-
||13.62 || 61.4 +/- 2.9 || 63.6 +/- 2.3 || 60.4 +/- 3.5
|-
||13.82 || 69.5 +/- 3.3 || 69.4 +/- 2.1 || 73.3 +/- 4.1
|-
||14.02 || 78.7 +/- 4.4 || 74.4 +/- 2.9 || 78.2 +/- 4.6
|-
||14.22 || 84.9 +/- 3.6 || 78 +/- 2.8 || 82.3 +/- 4.2
|-
||14.42 || 93.3 +/- 2.7 || 87.6 +/- 3.4 || 93 +/- 4.8
|-
||14.62 || 100.5 +/- 4 || 92.2 +/- 3.1 || 99.4 +/- 4.4
|-
||14.82 || 105.1 +/- 4.6 || 96.2 +/- 3 || 110.9 +/- 3.9
|-
||15.02 || 110.9 +/- 4.6 || 101.4 +/- 3.9 || 114.7 +/- 6.1
|-
||15.22 || 118.9 +/- 4.1 || 104.9 +/- 4.3 || 124.6 +/- 5.6
|-
||15.42 || 125.8 +/- 5.5 || 108.1 +/- 5.1 || 137.5 +/- 6.7
|-
||15.62 || 132.9 +/- 4.5 || 106.8 +/- 5 || 143.7 +/- 4.6
|-
||15.82 || 132.7 +/- 5.9 || 105.4 +/- 5.6 || 140.4 +/- 5
|-
||16.02 || 127.6 +/- 5.6 || 104.8 +/- 5 || 145.69 +/- 6.9
|-
||16.22 || 132.4 +/- 5.3 || 106.6 +/- 4.9 || 151.8 +/- 6.9
|-
||16.42 || 130 +/- 7.6 || 100.5 +/- 7.5 || 143 +/- 7.4
|-
||16.62 || 125.4 +/- 6.2 || 102.6 +/- 6.2 || 137.8 +/- 6.2
|-
||16.82 || 137.4 +/- 6.7 || 100.5 +/- 7.5 || 142.8 +/- 6
|-
||17.02 || 138.1 +/- 7.5 || 101 +/- 5.9 || 132.2 +/- 7.2
|-
||17.22 || 130.4 +/- 8.3 || 93.1 +/- 6.3 || 128.8 +/- 4.7
|-
||17.42 || 114.9 +/- 6 || 95.5 +/- 6.3 || 122.7 +/- 5.9
|-
||17.62 || 110.8 +/- 6 || 94.8 +/- 8 || 120.6 +/- 6.8
|-
||17.82 || 104.4 +/- 7.4 || 99.2 +/- 7.3 || 119.2 +/- 7.2
|-
||18.02 || 108.7 +/- 6.6 || 98.1 +/- 6.2 || 115.9 +/- 7
|-
||18.22 || 102.4 +/- 7.3 || 96.3 +/- 7.3 || 112.5 +/- 5.6
|-
||18.42 || 104.3 +/- 5.7 || 98.6 +/- 7.7 || 114.1 +/- 8.2
|-
||18.62 || 104.1 +/- 5.5 || 95.5 +/- 10|| 114.1 +/- 6.5
|-
||18.82 || 91.1 +/- 7.8 || 87.2 +/- 9.1 || 90.8 +/- 7.5
|-
||19.02 || 90.5 +/- 5.5 || 88.1 +/- 7.6 || 99.4 +/- 6.3
|-
||19.22 || 85.7 +/- 6.2 || 97 +/- 9.9 || 87.2 +/- 5.9
|-
||19.42 || 91.4 +/- 6.6 || 91.7 +/- 9.2 || 90.6 +/- 7.2
|-
||19.62 || 84.9 +/- 5.6 || 83.8 +/- 10 || 81.3 +/- 6.6
|-
||19.82 || 90.3 +/- 8.1 || 71.2 +/- 8 || 83.8 +/- 6.5
|-
||20.02 || 83 +/- 5.7 || 74.4 +/- 7.7 || 80 +/- 5.9
|-
||20.22 || 79.9 +/- 6.2 || 68.8 +/- 8 || 71.1 +/- 6.4
|-
||20.42 || 67.1 +/- 7.2 || 66.6 +/- 7 || 65 +/- 7.6
|-
||20.62 || 70.9 +/- 6.6 || 59.4 +/- 7.3 || 57 +/- 5.6
|-
||20.82 || 72.2 +/- 7.6 || 70.3 +/- 6.5 || 75.2 +/- 6.7
|-
||21.02 || 66.8 +/- 6.5 || 65.8 +/- 6.4 || 61.4 +/- 7.6
|-
||21.22 || 69.7 +/- 7 || 59.9 +/- 7.2 || 73.1 +/- 6.8
|-
||21.42 || 68.2 +/- 8.4 || 59.4 +/- 7 || 59 +/- 9.3
|-
||21.62 || 68.6 +/- 7.4 || 66.2 +/- 6.8 || 67.5 +/- 6.7
|-
||21.82 || 60.9 +/- 7.3 || 68 +/- 7.2 || 55 +/- 7.2
|-
||22.02 || 58.5 +/- 7.3 || 62.1 +/- 6.5 || 55.9 +/- 8.6
|-
||22.22 || 56 +/- 7.8 || 65.3 +/- 7 || 59.4 +/- 8.1
|-
||22.42 || 69.7 +/- 7.7 || 61.6 +/- 0.4 || 64 +/- 9.7
|-
||22.62 || 60.1 +/- 8.8 || 67.7 +/- 6.2 || 67 +/- 8.2
|-
||22.82 || 60.9 +/- 8.7 || 55.7 +/- 7.8 || 55.9 +/- 8.6
|-
||23.02 || 58.8 +/- 9.3 || 57.2 +/- 6.1 || 61.4 +/- 11.2
|-
||23.22 || 50.6 +/- 9.7 || 55.2 +/- 7.7 || 48.5 +/- 8.1
|-
||23.42 || 31.5 +/- 8.7 || 44.7 +/- 8.1 || 46.5 +/- 10.1
|-
||23.62 || 37.7 +/- 8.7 || 31.3 +/- 5.9 || 34 +/- 7.1
|-
||23.82 || 29.5 +/- 10.2 || 34.7 +/- 5.9 || 47.6 +/- 10.1
|-
||24.02 || 32.4 +/- 8.6 || 33 +/- 6.3 || 43.4 +/- 10.6
|-
||24.22 || 32.8 +/- 9.6 || 21.7 +/- 7.3 || 46.2 +/- 9.5
|-
|}

Similar data can be found in the link above. Below is the plot for all the reactions of interest.

Below is a plot of 3 different isotopes of selenium with their cross sections as a function of energy.

[[File:PhotonE vs XSect.png|200px]]

Now to find the relative yields, I approximated the integral the above graph using a left hand Riemann sum with an interval width of 1 MeV and multiplied it by the natural abundance in the sample. Below is a table of the reactions and their integrated cross sections.

{| border="3" cellpadding="5" cellspacing="0"
|| Reaction || Abundance || Integrated Cross Section (mb) [10->24 MeV]
|-
|| Se-82(gamma,n)Se-81 || 8.82% || 5429.19
|-
|| Se-80(gamma,n)Se-79 || 49.8% || 5249.6
|-
|| Se-76(gamma,n)Se-75 || 9.23% || 4703.1
|}

{| border="3" cellpadding="5" cellspacing="0"
|| Reaction || Abundance || Integrated Cross Section (mb) [10->18 MeV]
|-
|| Se-82(gamma,n)Se-81 || 8.82% || 3271.3
|-
|| Se-80(gamma,n)Se-79 || 49.8% || 3090.5
|-
|| Se-76(gamma,n)Se-75 || 9.23% || 2644.7
|}

Below are the equations for the relative yield of each isotope.

<math>\frac{{76 \atop 34\; }Se (\gamma,n){75 \atop \;Se}}{{80 \atop 34\; }Se (\gamma,n){79 \atop \;Se}} = \frac{Abundance \times \int_{10.02}^{24.02}\sigma dE}{Abundance \times \int_{10.02}^{24.02}\sigma dE} = \frac{0.0923 \times 4703.1}{0.498 \times 5249.6} = 0.17 = \frac{\sigma_{Se-75}}{\sigma_{Se-79}}</math>

<math>\frac{{82 \atop 34\; }Se (\gamma,n){81 \atop \;Se}}{{80 \atop 34\; }Se (\gamma,n){79 \atop \;Se}} = \frac{Abundance \times \int_{10.02}^{24.02}\sigma dE}{Abundance \times \int_{10.02}^{24.02}\sigma dE} = \frac{0.0882 \times 5429.19}{0.498 \times 5249.6} = 0.19</math>

As of recently, the beam energy has been lowered to 18 MeV, so the relative yield for each isotope now becomes

<math>\frac{{76 \atop 34\; }Se (\gamma,n){75 \atop \;Se}}{{80 \atop 34\; }Se (\gamma,n){79 \atop \;Se}} = \frac{Abundance \times \int_{10.02}^{18.02}\sigma dE}{Abundance \times \int_{10.02}^{18.02}\sigma dE} = \frac{0.0923 \times 2644.7}{0.498 \times 3090.5} = 0.16 = \frac{\sigma_{Se-75}}{\sigma_{Se-79}}</math>

<math>\frac{{82 \atop 34\; }Se (\gamma,n){81 \atop \;Se}}{{80 \atop 34\; }Se (\gamma,n){79 \atop \;Se}} = \frac{Abundance \times \int_{10.02}^{18.02}\sigma dE}{Abundance \times \int_{10.02}^{18.02}\sigma dE} = \frac{0.0882 \times 3271.3}{0.498 \times 3090.5} = 0.18</math>

===Activity Productions===

Let

;<math>N(t)</math> = The number of activated atoms per cubic cm at time <math>t</math>
;<math>\mathcal{N}</math> =The number density of the target = <math>\frac{\rho N_A}{A}</math>[ Atoms/cm^3]
;<math>\rho</math> = material density [g/cm^3]
;<math>N_A</math> = Avagadro's number = <math>6 \times 10^{23}</math> g/mole
; <math>A</math> = Atomic Number
;<math> \phi</math> = incident photon flux ( photons/sec/cm/cm)

The rate of activated nuclei production is estimated by subtracting the rate of decay from the rate of production

<math>\frac{dN(t)}{dt} = N \sigma \phi - \lambda N(t)</math>

where

<math>\lambda</math> = half life of activated nucleus

:<math>\Rightarrow N(t) = \frac{N \sigma \phi}{\lambda}\left ( 1 - e^{-\lambda t} \right )</math>

The production rate ratio of Se-79 to Se-75 is

<math>\frac{N_{Se-79}}{N_{Se-75}} = \left ( \frac{\sigma_{Se-79}}{\sigma_{Se-75} }\right ) \left ( \frac{\lambda_{Se-75}}{\lambda_{Se-79}}\right ) = \left ( \frac{100}{15} \right ) \left ( \frac{119}{10^8} \right ) </math>
===Activity Productions===

Although the investigation of provenance will involve a comparison of isotope ratios, one will need to determine the detection limit of measuring each of those isotopes.

The amount of activated nucleii, N(t), is governed by the production rate equation below.

:<math>\Rightarrow N(t) = \frac{N \sigma \phi}{\lambda}\left ( 1 - e^{-\lambda t} \right )</math>

The number of target uncle, N, is determine using

<math>N= n_T V_T \int \sigma \phi dE</math>

<math>n_T</math> is the number of target nucleii per volume, <math>V_T</math> is the amount of volume irradiated

Our goal will be to determine <math>n_T</math>

One can use Nickel as a normalization target to remove the photon flux <math>(\phi)</math> from the integral leaving just an integral over the cross section.

[[PAA_Selenium#Can_one_perform_PAA_measurements_of_Se-82_and_Se-76.3F]]

Se PAA Reactions

2018-02-23T16:56:54Z

Starvale:

[[PAA_Selenium#Can_one_perform_PAA_measurements_of_Se-82_and_Se-76.3F]]
==Single and double particle knockout reactions==

[[File:TableOfReactions.jpg]|600px]
==Neutron knockout of Se-82==
If you knock a neutron out of Se-82 you produce the unstable isotope Se-81 which Beta emitts with half life of 18.45 min and a meta-state that emmits a 103 keV gamma with a 57.28 minute half life.

<math>{82 \atop 34\; }Se (\gamma,n){81 \atop \; }Se</math>

Prominent decay photons from an IT are

276 keV and 290 keV for the 57 minute half life isotope, 566 & 828 have less than half the intensity of the 276 and 290

The minimum energy required to knock out a neutron from this isotope is

(Mass of Se-81)-(Mass of Se-82)+(Mass of 1 neutron)[MeV/c^2] = 73511.651 - 744442.2136 + 939.57 -> 9.0 MeV

you can see the line and half life in the root file /data/IAC/Se/Feb2017Run/Pure_Se_cat.root file on daq1 using the commands

MPA->Draw("-2.7285+0.815579*evt.Chan","evt.Chan>338 && evt.Chan < 344 && evt.ADCid==1");

MPA->Draw("evt.Sec/60","evt.Chan>338 && evt.Chan < 344 && evt.ADCid==1");

==Neutron knockout of Se-76==
If you knock a neutron out of Se-76 you produce the unstable isotope Se-75 which has a half life of 119 days.

<math>{76 \atop\; 34}Se (\gamma,n){75 \atop \; }Se</math>

The prominent photons emitted have the following energies in order of high to low intensity

136, 264, and 279 keV

http://www.nucleide.org/DDEP_WG/Nuclides/Se-75_tables.pdf

The article below describes how plant material and soil contain Se-76 to Se-82 ratios that differ from other natural samples by 1.5%. They argue that it is due to the bacteria living in plant material.

[[File:Krouse_CanJournChem_40_1962_p367.pdf]]

Plant material is a natural way to sample the selenium content to determine if there are difference isotopic ratios due to the impact of human activities on the environment.

The energy required to knock out a neutron from this isotope is

(Mass of Se-75) + (Mass of 1 neutron) - (Mass of Se-81)[MeV/c^2] = 69790.3321 + 939.57 - 70718.1 -> 11.8 MeV

==Relative Yield Calculations==
For this section, I am interested in finding the relative yield of Se-79 when compared to Se-81 and Se-75. Cross sections were found at this website: http://www-nds.indcentre.org.in/exfor/servlet/X4sSearch5?EntryID=220070

===Cross-section===

Below is a table of the cross sections for all of the reactions of interest (Se-76 -> Se-75, Se-82 -> Se-81, and Se-80 -> Se-79).

{| border="3" cellpadding="5" cellspacing="0"
||Energy (MeV) || Se-80 -> Se-79 (mb) || Se-76 -> Se- 75 (mb) || Se-82 -> Se-81 (mb)
|-
||9.42 || ** || ** || 5.58 +/- 0.5
|-
||9.62 || ** || ** || 8.7 +/- 0.5
|-
||9.82 || ** || ** || 10.8 +/- 0.5
|-
||10.02 || 7.1 +/- 0.2 || ** || 12.4 +/- 0.7
|-
||10.22 || 10.3 +/- 0.4 ||0.4 +/- 0.2 || 15 +/- 0.9
|-
||10.42 || 12.9 +/- 0.5 || 0.8 +/- 0.3 || 15.4 +/- 0.9
|-
||10.62 || 16.2 +/- 0.5 || 4.7 +/- 0.3 || 17.3 +/- 1.1
|-
||10.82 || 19.2 +/- 0.6 || 6.6 +/- 0.4 || 21 +/- 1.1
|-
||11.02 || 22 +/- 0.6 || 9.9 +/- 0.3 || 21.8 +/- 1.4
|-
||11.22 || 23.8 +/- 1 || 12.2 +/- 0.4 || 22.5 +/- 1.9
|-
||11.42 || 28 +/- 1 || 19.5 +/- 0.5 || 27.7 +/- 1.5
|-
||11.62 || 28.6 +/- 1.2 || 23.5 +/- 0.5 || 27.8 +/- 2
|-
||11.82 || 30.4 +/- 1.5 || 26.7 +/- 0.8 || 28.4 +/- 1.8
|-
||12.02 || 33 +/- 1.4 || 32 +/- 0.8 || 31.9 +/- 1.8
|-
||12.22 || 34.9 +/- 1.8 || 36.3 +/- 0.8 || 34.5 +/- 2.4
|-
||12.42 || 37.6 +/- 1.4 || 38.8 +/- 1.4 || 38.3 +/- 2.8
|-
||12.62 || 41.5 +/- 2 || 40.9 +/- 1.4 || 42.6 +/- 3
|-
||12.82 || 43.6 +/- 2.5 || 46.7 +/- 1.6 || 41 +/- 3.2
|-
||13.02 || 46.7 +/- 2.8 || 49.2 +/- 1.8 || 48.8 +/- 2.5
|-
||13.22 || 51.9 +/- 2.6 || 55.8 +/- 1.5 || 53.3 +/- 3.4
|-
||13.42 || 56.7 +/- 1.5 || 56 +/- 2.5 || 52.7 +/- 4.3
|-
||13.62 || 61.4 +/- 2.9 || 63.6 +/- 2.3 || 60.4 +/- 3.5
|-
||13.82 || 69.5 +/- 3.3 || 69.4 +/- 2.1 || 73.3 +/- 4.1
|-
||14.02 || 78.7 +/- 4.4 || 74.4 +/- 2.9 || 78.2 +/- 4.6
|-
||14.22 || 84.9 +/- 3.6 || 78 +/- 2.8 || 82.3 +/- 4.2
|-
||14.42 || 93.3 +/- 2.7 || 87.6 +/- 3.4 || 93 +/- 4.8
|-
||14.62 || 100.5 +/- 4 || 92.2 +/- 3.1 || 99.4 +/- 4.4
|-
||14.82 || 105.1 +/- 4.6 || 96.2 +/- 3 || 110.9 +/- 3.9
|-
||15.02 || 110.9 +/- 4.6 || 101.4 +/- 3.9 || 114.7 +/- 6.1
|-
||15.22 || 118.9 +/- 4.1 || 104.9 +/- 4.3 || 124.6 +/- 5.6
|-
||15.42 || 125.8 +/- 5.5 || 108.1 +/- 5.1 || 137.5 +/- 6.7
|-
||15.62 || 132.9 +/- 4.5 || 106.8 +/- 5 || 143.7 +/- 4.6
|-
||15.82 || 132.7 +/- 5.9 || 105.4 +/- 5.6 || 140.4 +/- 5
|-
||16.02 || 127.6 +/- 5.6 || 104.8 +/- 5 || 145.69 +/- 6.9
|-
||16.22 || 132.4 +/- 5.3 || 106.6 +/- 4.9 || 151.8 +/- 6.9
|-
||16.42 || 130 +/- 7.6 || 100.5 +/- 7.5 || 143 +/- 7.4
|-
||16.62 || 125.4 +/- 6.2 || 102.6 +/- 6.2 || 137.8 +/- 6.2
|-
||16.82 || 137.4 +/- 6.7 || 100.5 +/- 7.5 || 142.8 +/- 6
|-
||17.02 || 138.1 +/- 7.5 || 101 +/- 5.9 || 132.2 +/- 7.2
|-
||17.22 || 130.4 +/- 8.3 || 93.1 +/- 6.3 || 128.8 +/- 4.7
|-
||17.42 || 114.9 +/- 6 || 95.5 +/- 6.3 || 122.7 +/- 5.9
|-
||17.62 || 110.8 +/- 6 || 94.8 +/- 8 || 120.6 +/- 6.8
|-
||17.82 || 104.4 +/- 7.4 || 99.2 +/- 7.3 || 119.2 +/- 7.2
|-
||18.02 || 108.7 +/- 6.6 || 98.1 +/- 6.2 || 115.9 +/- 7
|-
||18.22 || 102.4 +/- 7.3 || 96.3 +/- 7.3 || 112.5 +/- 5.6
|-
||18.42 || 104.3 +/- 5.7 || 98.6 +/- 7.7 || 114.1 +/- 8.2
|-
||18.62 || 104.1 +/- 5.5 || 95.5 +/- 10|| 114.1 +/- 6.5
|-
||18.82 || 91.1 +/- 7.8 || 87.2 +/- 9.1 || 90.8 +/- 7.5
|-
||19.02 || 90.5 +/- 5.5 || 88.1 +/- 7.6 || 99.4 +/- 6.3
|-
||19.22 || 85.7 +/- 6.2 || 97 +/- 9.9 || 87.2 +/- 5.9
|-
||19.42 || 91.4 +/- 6.6 || 91.7 +/- 9.2 || 90.6 +/- 7.2
|-
||19.62 || 84.9 +/- 5.6 || 83.8 +/- 10 || 81.3 +/- 6.6
|-
||19.82 || 90.3 +/- 8.1 || 71.2 +/- 8 || 83.8 +/- 6.5
|-
||20.02 || 83 +/- 5.7 || 74.4 +/- 7.7 || 80 +/- 5.9
|-
||20.22 || 79.9 +/- 6.2 || 68.8 +/- 8 || 71.1 +/- 6.4
|-
||20.42 || 67.1 +/- 7.2 || 66.6 +/- 7 || 65 +/- 7.6
|-
||20.62 || 70.9 +/- 6.6 || 59.4 +/- 7.3 || 57 +/- 5.6
|-
||20.82 || 72.2 +/- 7.6 || 70.3 +/- 6.5 || 75.2 +/- 6.7
|-
||21.02 || 66.8 +/- 6.5 || 65.8 +/- 6.4 || 61.4 +/- 7.6
|-
||21.22 || 69.7 +/- 7 || 59.9 +/- 7.2 || 73.1 +/- 6.8
|-
||21.42 || 68.2 +/- 8.4 || 59.4 +/- 7 || 59 +/- 9.3
|-
||21.62 || 68.6 +/- 7.4 || 66.2 +/- 6.8 || 67.5 +/- 6.7
|-
||21.82 || 60.9 +/- 7.3 || 68 +/- 7.2 || 55 +/- 7.2
|-
||22.02 || 58.5 +/- 7.3 || 62.1 +/- 6.5 || 55.9 +/- 8.6
|-
||22.22 || 56 +/- 7.8 || 65.3 +/- 7 || 59.4 +/- 8.1
|-
||22.42 || 69.7 +/- 7.7 || 61.6 +/- 0.4 || 64 +/- 9.7
|-
||22.62 || 60.1 +/- 8.8 || 67.7 +/- 6.2 || 67 +/- 8.2
|-
||22.82 || 60.9 +/- 8.7 || 55.7 +/- 7.8 || 55.9 +/- 8.6
|-
||23.02 || 58.8 +/- 9.3 || 57.2 +/- 6.1 || 61.4 +/- 11.2
|-
||23.22 || 50.6 +/- 9.7 || 55.2 +/- 7.7 || 48.5 +/- 8.1
|-
||23.42 || 31.5 +/- 8.7 || 44.7 +/- 8.1 || 46.5 +/- 10.1
|-
||23.62 || 37.7 +/- 8.7 || 31.3 +/- 5.9 || 34 +/- 7.1
|-
||23.82 || 29.5 +/- 10.2 || 34.7 +/- 5.9 || 47.6 +/- 10.1
|-
||24.02 || 32.4 +/- 8.6 || 33 +/- 6.3 || 43.4 +/- 10.6
|-
||24.22 || 32.8 +/- 9.6 || 21.7 +/- 7.3 || 46.2 +/- 9.5
|-
|}

Similar data can be found in the link above. Below is the plot for all the reactions of interest.

Below is a plot of 3 different isotopes of selenium with their cross sections as a function of energy.

[[File:PhotonE vs XSect.png|200px]]

Now to find the relative yields, I approximated the integral the above graph using a left hand Riemann sum with an interval width of 1 MeV and multiplied it by the natural abundance in the sample. Below is a table of the reactions and their integrated cross sections.

{| border="3" cellpadding="5" cellspacing="0"
|| Reaction || Abundance || Integrated Cross Section (mb) [10->24 MeV]
|-
|| Se-82(gamma,n)Se-81 || 8.82% || 5429.19
|-
|| Se-80(gamma,n)Se-79 || 49.8% || 5249.6
|-
|| Se-76(gamma,n)Se-75 || 9.23% || 4703.1
|}

{| border="3" cellpadding="5" cellspacing="0"
|| Reaction || Abundance || Integrated Cross Section (mb) [10->18 MeV]
|-
|| Se-82(gamma,n)Se-81 || 8.82% || 3271.3
|-
|| Se-80(gamma,n)Se-79 || 49.8% || 3090.5
|-
|| Se-76(gamma,n)Se-75 || 9.23% || 2644.7
|}

Below are the equations for the relative yield of each isotope.

<math>\frac{{76 \atop 34\; }Se (\gamma,n){75 \atop \;Se}}{{80 \atop 34\; }Se (\gamma,n){79 \atop \;Se}} = \frac{Abundance \times \int_{10.02}^{24.02}\sigma dE}{Abundance \times \int_{10.02}^{24.02}\sigma dE} = \frac{0.0923 \times 4703.1}{0.498 \times 5249.6} = 0.17 = \frac{\sigma_{Se-75}}{\sigma_{Se-79}}</math>

<math>\frac{{82 \atop 34\; }Se (\gamma,n){81 \atop \;Se}}{{80 \atop 34\; }Se (\gamma,n){79 \atop \;Se}} = \frac{Abundance \times \int_{10.02}^{24.02}\sigma dE}{Abundance \times \int_{10.02}^{24.02}\sigma dE} = \frac{0.0882 \times 5429.19}{0.498 \times 5249.6} = 0.19</math>

As of recently, the beam energy has been lowered to 18 MeV, so the relative yield for each isotope now becomes

<math>\frac{{76 \atop 34\; }Se (\gamma,n){75 \atop \;Se}}{{80 \atop 34\; }Se (\gamma,n){79 \atop \;Se}} = \frac{Abundance \times \int_{10.02}^{18.02}\sigma dE}{Abundance \times \int_{10.02}^{18.02}\sigma dE} = \frac{0.0923 \times 2644.7}{0.498 \times 3090.5} = 0.16 = \frac{\sigma_{Se-75}}{\sigma_{Se-79}}</math>

<math>\frac{{82 \atop 34\; }Se (\gamma,n){81 \atop \;Se}}{{80 \atop 34\; }Se (\gamma,n){79 \atop \;Se}} = \frac{Abundance \times \int_{10.02}^{18.02}\sigma dE}{Abundance \times \int_{10.02}^{18.02}\sigma dE} = \frac{0.0882 \times 3271.3}{0.498 \times 3090.5} = 0.18</math>

===Activity Productions===

Let

;<math>N(t)</math> = The number of activated atoms per cubic cm at time <math>t</math>
;<math>\mathcal{N}</math> =The number density of the target = <math>\frac{\rho N_A}{A}</math>[ Atoms/cm^3]
;<math>\rho</math> = material density [g/cm^3]
;<math>N_A</math> = Avagadro's number = <math>6 \times 10^{23}</math> g/mole
; <math>A</math> = Atomic Number
;<math> \phi</math> = incident photon flux ( photons/sec/cm/cm)

The rate of activated nuclei production is estimated by subtracting the rate of decay from the rate of production

<math>\frac{dN(t)}{dt} = N \sigma \phi - \lambda N(t)</math>

where

<math>\lambda</math> = half life of activated nucleus

:<math>\Rightarrow N(t) = \frac{N \sigma \phi}{\lambda}\left ( 1 - e^{-\lambda t} \right )</math>

The production rate ratio of Se-79 to Se-75 is

<math>\frac{N_{Se-79}}{N_{Se-75}} = \left ( \frac{\sigma_{Se-79}}{\sigma_{Se-75} }\right ) \left ( \frac{\lambda_{Se-75}}{\lambda_{Se-79}}\right ) = \left ( \frac{100}{15} \right ) \left ( \frac{119}{10^8} \right ) </math>
===Activity Productions===

Although the investigation of provenance will involve a comparison of isotope ratios, one will need to determine the detection limit of measuring each of those isotopes.

The amount of activated nucleii, N(t), is governed by the production rate equation below.

:<math>\Rightarrow N(t) = \frac{N \sigma \phi}{\lambda}\left ( 1 - e^{-\lambda t} \right )</math>

The number of target uncle, N, is determine using

<math>N= n_T V_T \int \sigma \phi dE</math>

<math>n_T</math> is the number of target nucleii per volume, <math>V_T</math> is the amount of volume irradiated

Our goal will be to determine <math>n_T</math>

One can use Nickel as a normalization target to remove the photon flux <math>(\phi)</math> from the integral leaving just an integral over the cross section.

[[PAA_Selenium#Can_one_perform_PAA_measurements_of_Se-82_and_Se-76.3F]]

File:TableOfReactions.jpg

2018-02-23T16:55:10Z

Starvale:

Se PAA Reactions

2018-02-23T16:54:57Z

Starvale:

[[PAA_Selenium#Can_one_perform_PAA_measurements_of_Se-82_and_Se-76.3F]]
==Single and double particle knockout reactions==

[[File:TableOfReactions.jpg]]
==Neutron knockout of Se-82==
If you knock a neutron out of Se-82 you produce the unstable isotope Se-81 which Beta emitts with half life of 18.45 min and a meta-state that emmits a 103 keV gamma with a 57.28 minute half life.

<math>{82 \atop 34\; }Se (\gamma,n){81 \atop \; }Se</math>

Prominent decay photons from an IT are

276 keV and 290 keV for the 57 minute half life isotope, 566 & 828 have less than half the intensity of the 276 and 290

The minimum energy required to knock out a neutron from this isotope is

(Mass of Se-81)-(Mass of Se-82)+(Mass of 1 neutron)[MeV/c^2] = 73511.651 - 744442.2136 + 939.57 -> 9.0 MeV

you can see the line and half life in the root file /data/IAC/Se/Feb2017Run/Pure_Se_cat.root file on daq1 using the commands

MPA->Draw("-2.7285+0.815579*evt.Chan","evt.Chan>338 && evt.Chan < 344 && evt.ADCid==1");

MPA->Draw("evt.Sec/60","evt.Chan>338 && evt.Chan < 344 && evt.ADCid==1");

==Neutron knockout of Se-76==
If you knock a neutron out of Se-76 you produce the unstable isotope Se-75 which has a half life of 119 days.

<math>{76 \atop\; 34}Se (\gamma,n){75 \atop \; }Se</math>

The prominent photons emitted have the following energies in order of high to low intensity

136, 264, and 279 keV

http://www.nucleide.org/DDEP_WG/Nuclides/Se-75_tables.pdf

The article below describes how plant material and soil contain Se-76 to Se-82 ratios that differ from other natural samples by 1.5%. They argue that it is due to the bacteria living in plant material.

[[File:Krouse_CanJournChem_40_1962_p367.pdf]]

Plant material is a natural way to sample the selenium content to determine if there are difference isotopic ratios due to the impact of human activities on the environment.

The energy required to knock out a neutron from this isotope is

(Mass of Se-75) + (Mass of 1 neutron) - (Mass of Se-81)[MeV/c^2] = 69790.3321 + 939.57 - 70718.1 -> 11.8 MeV

==Relative Yield Calculations==
For this section, I am interested in finding the relative yield of Se-79 when compared to Se-81 and Se-75. Cross sections were found at this website: http://www-nds.indcentre.org.in/exfor/servlet/X4sSearch5?EntryID=220070

===Cross-section===

Below is a table of the cross sections for all of the reactions of interest (Se-76 -> Se-75, Se-82 -> Se-81, and Se-80 -> Se-79).

{| border="3" cellpadding="5" cellspacing="0"
||Energy (MeV) || Se-80 -> Se-79 (mb) || Se-76 -> Se- 75 (mb) || Se-82 -> Se-81 (mb)
|-
||9.42 || ** || ** || 5.58 +/- 0.5
|-
||9.62 || ** || ** || 8.7 +/- 0.5
|-
||9.82 || ** || ** || 10.8 +/- 0.5
|-
||10.02 || 7.1 +/- 0.2 || ** || 12.4 +/- 0.7
|-
||10.22 || 10.3 +/- 0.4 ||0.4 +/- 0.2 || 15 +/- 0.9
|-
||10.42 || 12.9 +/- 0.5 || 0.8 +/- 0.3 || 15.4 +/- 0.9
|-
||10.62 || 16.2 +/- 0.5 || 4.7 +/- 0.3 || 17.3 +/- 1.1
|-
||10.82 || 19.2 +/- 0.6 || 6.6 +/- 0.4 || 21 +/- 1.1
|-
||11.02 || 22 +/- 0.6 || 9.9 +/- 0.3 || 21.8 +/- 1.4
|-
||11.22 || 23.8 +/- 1 || 12.2 +/- 0.4 || 22.5 +/- 1.9
|-
||11.42 || 28 +/- 1 || 19.5 +/- 0.5 || 27.7 +/- 1.5
|-
||11.62 || 28.6 +/- 1.2 || 23.5 +/- 0.5 || 27.8 +/- 2
|-
||11.82 || 30.4 +/- 1.5 || 26.7 +/- 0.8 || 28.4 +/- 1.8
|-
||12.02 || 33 +/- 1.4 || 32 +/- 0.8 || 31.9 +/- 1.8
|-
||12.22 || 34.9 +/- 1.8 || 36.3 +/- 0.8 || 34.5 +/- 2.4
|-
||12.42 || 37.6 +/- 1.4 || 38.8 +/- 1.4 || 38.3 +/- 2.8
|-
||12.62 || 41.5 +/- 2 || 40.9 +/- 1.4 || 42.6 +/- 3
|-
||12.82 || 43.6 +/- 2.5 || 46.7 +/- 1.6 || 41 +/- 3.2
|-
||13.02 || 46.7 +/- 2.8 || 49.2 +/- 1.8 || 48.8 +/- 2.5
|-
||13.22 || 51.9 +/- 2.6 || 55.8 +/- 1.5 || 53.3 +/- 3.4
|-
||13.42 || 56.7 +/- 1.5 || 56 +/- 2.5 || 52.7 +/- 4.3
|-
||13.62 || 61.4 +/- 2.9 || 63.6 +/- 2.3 || 60.4 +/- 3.5
|-
||13.82 || 69.5 +/- 3.3 || 69.4 +/- 2.1 || 73.3 +/- 4.1
|-
||14.02 || 78.7 +/- 4.4 || 74.4 +/- 2.9 || 78.2 +/- 4.6
|-
||14.22 || 84.9 +/- 3.6 || 78 +/- 2.8 || 82.3 +/- 4.2
|-
||14.42 || 93.3 +/- 2.7 || 87.6 +/- 3.4 || 93 +/- 4.8
|-
||14.62 || 100.5 +/- 4 || 92.2 +/- 3.1 || 99.4 +/- 4.4
|-
||14.82 || 105.1 +/- 4.6 || 96.2 +/- 3 || 110.9 +/- 3.9
|-
||15.02 || 110.9 +/- 4.6 || 101.4 +/- 3.9 || 114.7 +/- 6.1
|-
||15.22 || 118.9 +/- 4.1 || 104.9 +/- 4.3 || 124.6 +/- 5.6
|-
||15.42 || 125.8 +/- 5.5 || 108.1 +/- 5.1 || 137.5 +/- 6.7
|-
||15.62 || 132.9 +/- 4.5 || 106.8 +/- 5 || 143.7 +/- 4.6
|-
||15.82 || 132.7 +/- 5.9 || 105.4 +/- 5.6 || 140.4 +/- 5
|-
||16.02 || 127.6 +/- 5.6 || 104.8 +/- 5 || 145.69 +/- 6.9
|-
||16.22 || 132.4 +/- 5.3 || 106.6 +/- 4.9 || 151.8 +/- 6.9
|-
||16.42 || 130 +/- 7.6 || 100.5 +/- 7.5 || 143 +/- 7.4
|-
||16.62 || 125.4 +/- 6.2 || 102.6 +/- 6.2 || 137.8 +/- 6.2
|-
||16.82 || 137.4 +/- 6.7 || 100.5 +/- 7.5 || 142.8 +/- 6
|-
||17.02 || 138.1 +/- 7.5 || 101 +/- 5.9 || 132.2 +/- 7.2
|-
||17.22 || 130.4 +/- 8.3 || 93.1 +/- 6.3 || 128.8 +/- 4.7
|-
||17.42 || 114.9 +/- 6 || 95.5 +/- 6.3 || 122.7 +/- 5.9
|-
||17.62 || 110.8 +/- 6 || 94.8 +/- 8 || 120.6 +/- 6.8
|-
||17.82 || 104.4 +/- 7.4 || 99.2 +/- 7.3 || 119.2 +/- 7.2
|-
||18.02 || 108.7 +/- 6.6 || 98.1 +/- 6.2 || 115.9 +/- 7
|-
||18.22 || 102.4 +/- 7.3 || 96.3 +/- 7.3 || 112.5 +/- 5.6
|-
||18.42 || 104.3 +/- 5.7 || 98.6 +/- 7.7 || 114.1 +/- 8.2
|-
||18.62 || 104.1 +/- 5.5 || 95.5 +/- 10|| 114.1 +/- 6.5
|-
||18.82 || 91.1 +/- 7.8 || 87.2 +/- 9.1 || 90.8 +/- 7.5
|-
||19.02 || 90.5 +/- 5.5 || 88.1 +/- 7.6 || 99.4 +/- 6.3
|-
||19.22 || 85.7 +/- 6.2 || 97 +/- 9.9 || 87.2 +/- 5.9
|-
||19.42 || 91.4 +/- 6.6 || 91.7 +/- 9.2 || 90.6 +/- 7.2
|-
||19.62 || 84.9 +/- 5.6 || 83.8 +/- 10 || 81.3 +/- 6.6
|-
||19.82 || 90.3 +/- 8.1 || 71.2 +/- 8 || 83.8 +/- 6.5
|-
||20.02 || 83 +/- 5.7 || 74.4 +/- 7.7 || 80 +/- 5.9
|-
||20.22 || 79.9 +/- 6.2 || 68.8 +/- 8 || 71.1 +/- 6.4
|-
||20.42 || 67.1 +/- 7.2 || 66.6 +/- 7 || 65 +/- 7.6
|-
||20.62 || 70.9 +/- 6.6 || 59.4 +/- 7.3 || 57 +/- 5.6
|-
||20.82 || 72.2 +/- 7.6 || 70.3 +/- 6.5 || 75.2 +/- 6.7
|-
||21.02 || 66.8 +/- 6.5 || 65.8 +/- 6.4 || 61.4 +/- 7.6
|-
||21.22 || 69.7 +/- 7 || 59.9 +/- 7.2 || 73.1 +/- 6.8
|-
||21.42 || 68.2 +/- 8.4 || 59.4 +/- 7 || 59 +/- 9.3
|-
||21.62 || 68.6 +/- 7.4 || 66.2 +/- 6.8 || 67.5 +/- 6.7
|-
||21.82 || 60.9 +/- 7.3 || 68 +/- 7.2 || 55 +/- 7.2
|-
||22.02 || 58.5 +/- 7.3 || 62.1 +/- 6.5 || 55.9 +/- 8.6
|-
||22.22 || 56 +/- 7.8 || 65.3 +/- 7 || 59.4 +/- 8.1
|-
||22.42 || 69.7 +/- 7.7 || 61.6 +/- 0.4 || 64 +/- 9.7
|-
||22.62 || 60.1 +/- 8.8 || 67.7 +/- 6.2 || 67 +/- 8.2
|-
||22.82 || 60.9 +/- 8.7 || 55.7 +/- 7.8 || 55.9 +/- 8.6
|-
||23.02 || 58.8 +/- 9.3 || 57.2 +/- 6.1 || 61.4 +/- 11.2
|-
||23.22 || 50.6 +/- 9.7 || 55.2 +/- 7.7 || 48.5 +/- 8.1
|-
||23.42 || 31.5 +/- 8.7 || 44.7 +/- 8.1 || 46.5 +/- 10.1
|-
||23.62 || 37.7 +/- 8.7 || 31.3 +/- 5.9 || 34 +/- 7.1
|-
||23.82 || 29.5 +/- 10.2 || 34.7 +/- 5.9 || 47.6 +/- 10.1
|-
||24.02 || 32.4 +/- 8.6 || 33 +/- 6.3 || 43.4 +/- 10.6
|-
||24.22 || 32.8 +/- 9.6 || 21.7 +/- 7.3 || 46.2 +/- 9.5
|-
|}

Similar data can be found in the link above. Below is the plot for all the reactions of interest.

Below is a plot of 3 different isotopes of selenium with their cross sections as a function of energy.

[[File:PhotonE vs XSect.png|200px]]

Now to find the relative yields, I approximated the integral the above graph using a left hand Riemann sum with an interval width of 1 MeV and multiplied it by the natural abundance in the sample. Below is a table of the reactions and their integrated cross sections.

{| border="3" cellpadding="5" cellspacing="0"
|| Reaction || Abundance || Integrated Cross Section (mb) [10->24 MeV]
|-
|| Se-82(gamma,n)Se-81 || 8.82% || 5429.19
|-
|| Se-80(gamma,n)Se-79 || 49.8% || 5249.6
|-
|| Se-76(gamma,n)Se-75 || 9.23% || 4703.1
|}

{| border="3" cellpadding="5" cellspacing="0"
|| Reaction || Abundance || Integrated Cross Section (mb) [10->18 MeV]
|-
|| Se-82(gamma,n)Se-81 || 8.82% || 3271.3
|-
|| Se-80(gamma,n)Se-79 || 49.8% || 3090.5
|-
|| Se-76(gamma,n)Se-75 || 9.23% || 2644.7
|}

Below are the equations for the relative yield of each isotope.

<math>\frac{{76 \atop 34\; }Se (\gamma,n){75 \atop \;Se}}{{80 \atop 34\; }Se (\gamma,n){79 \atop \;Se}} = \frac{Abundance \times \int_{10.02}^{24.02}\sigma dE}{Abundance \times \int_{10.02}^{24.02}\sigma dE} = \frac{0.0923 \times 4703.1}{0.498 \times 5249.6} = 0.17 = \frac{\sigma_{Se-75}}{\sigma_{Se-79}}</math>

<math>\frac{{82 \atop 34\; }Se (\gamma,n){81 \atop \;Se}}{{80 \atop 34\; }Se (\gamma,n){79 \atop \;Se}} = \frac{Abundance \times \int_{10.02}^{24.02}\sigma dE}{Abundance \times \int_{10.02}^{24.02}\sigma dE} = \frac{0.0882 \times 5429.19}{0.498 \times 5249.6} = 0.19</math>

As of recently, the beam energy has been lowered to 18 MeV, so the relative yield for each isotope now becomes

<math>\frac{{76 \atop 34\; }Se (\gamma,n){75 \atop \;Se}}{{80 \atop 34\; }Se (\gamma,n){79 \atop \;Se}} = \frac{Abundance \times \int_{10.02}^{18.02}\sigma dE}{Abundance \times \int_{10.02}^{18.02}\sigma dE} = \frac{0.0923 \times 2644.7}{0.498 \times 3090.5} = 0.16 = \frac{\sigma_{Se-75}}{\sigma_{Se-79}}</math>

<math>\frac{{82 \atop 34\; }Se (\gamma,n){81 \atop \;Se}}{{80 \atop 34\; }Se (\gamma,n){79 \atop \;Se}} = \frac{Abundance \times \int_{10.02}^{18.02}\sigma dE}{Abundance \times \int_{10.02}^{18.02}\sigma dE} = \frac{0.0882 \times 3271.3}{0.498 \times 3090.5} = 0.18</math>

===Activity Productions===

Let

;<math>N(t)</math> = The number of activated atoms per cubic cm at time <math>t</math>
;<math>\mathcal{N}</math> =The number density of the target = <math>\frac{\rho N_A}{A}</math>[ Atoms/cm^3]
;<math>\rho</math> = material density [g/cm^3]
;<math>N_A</math> = Avagadro's number = <math>6 \times 10^{23}</math> g/mole
; <math>A</math> = Atomic Number
;<math> \phi</math> = incident photon flux ( photons/sec/cm/cm)

The rate of activated nuclei production is estimated by subtracting the rate of decay from the rate of production

<math>\frac{dN(t)}{dt} = N \sigma \phi - \lambda N(t)</math>

where

<math>\lambda</math> = half life of activated nucleus

:<math>\Rightarrow N(t) = \frac{N \sigma \phi}{\lambda}\left ( 1 - e^{-\lambda t} \right )</math>

The production rate ratio of Se-79 to Se-75 is

<math>\frac{N_{Se-79}}{N_{Se-75}} = \left ( \frac{\sigma_{Se-79}}{\sigma_{Se-75} }\right ) \left ( \frac{\lambda_{Se-75}}{\lambda_{Se-79}}\right ) = \left ( \frac{100}{15} \right ) \left ( \frac{119}{10^8} \right ) </math>
===Activity Productions===

Although the investigation of provenance will involve a comparison of isotope ratios, one will need to determine the detection limit of measuring each of those isotopes.

The amount of activated nucleii, N(t), is governed by the production rate equation below.

:<math>\Rightarrow N(t) = \frac{N \sigma \phi}{\lambda}\left ( 1 - e^{-\lambda t} \right )</math>

The number of target uncle, N, is determine using

<math>N= n_T V_T \int \sigma \phi dE</math>

<math>n_T</math> is the number of target nucleii per volume, <math>V_T</math> is the amount of volume irradiated

Our goal will be to determine <math>n_T</math>

One can use Nickel as a normalization target to remove the photon flux <math>(\phi)</math> from the integral leaving just an integral over the cross section.

[[PAA_Selenium#Can_one_perform_PAA_measurements_of_Se-82_and_Se-76.3F]]

Se PAA Reactions

2018-02-23T16:52:38Z

Starvale:

[[PAA_Selenium#Can_one_perform_PAA_measurements_of_Se-82_and_Se-76.3F]]
==Single and double particle knockout reactions==

[[File:TableOfReactions.pdf]]
==Neutron knockout of Se-82==
If you knock a neutron out of Se-82 you produce the unstable isotope Se-81 which Beta emitts with half life of 18.45 min and a meta-state that emmits a 103 keV gamma with a 57.28 minute half life.

<math>{82 \atop 34\; }Se (\gamma,n){81 \atop \; }Se</math>

Prominent decay photons from an IT are

276 keV and 290 keV for the 57 minute half life isotope, 566 & 828 have less than half the intensity of the 276 and 290

The minimum energy required to knock out a neutron from this isotope is

(Mass of Se-81)-(Mass of Se-82)+(Mass of 1 neutron)[MeV/c^2] = 73511.651 - 744442.2136 + 939.57 -> 9.0 MeV

you can see the line and half life in the root file /data/IAC/Se/Feb2017Run/Pure_Se_cat.root file on daq1 using the commands

MPA->Draw("-2.7285+0.815579*evt.Chan","evt.Chan>338 && evt.Chan < 344 && evt.ADCid==1");

MPA->Draw("evt.Sec/60","evt.Chan>338 && evt.Chan < 344 && evt.ADCid==1");

==Neutron knockout of Se-76==
If you knock a neutron out of Se-76 you produce the unstable isotope Se-75 which has a half life of 119 days.

<math>{76 \atop\; 34}Se (\gamma,n){75 \atop \; }Se</math>

The prominent photons emitted have the following energies in order of high to low intensity

136, 264, and 279 keV

http://www.nucleide.org/DDEP_WG/Nuclides/Se-75_tables.pdf

The article below describes how plant material and soil contain Se-76 to Se-82 ratios that differ from other natural samples by 1.5%. They argue that it is due to the bacteria living in plant material.

[[File:Krouse_CanJournChem_40_1962_p367.pdf]]

Plant material is a natural way to sample the selenium content to determine if there are difference isotopic ratios due to the impact of human activities on the environment.

The energy required to knock out a neutron from this isotope is

(Mass of Se-75) + (Mass of 1 neutron) - (Mass of Se-81)[MeV/c^2] = 69790.3321 + 939.57 - 70718.1 -> 11.8 MeV

==Relative Yield Calculations==
For this section, I am interested in finding the relative yield of Se-79 when compared to Se-81 and Se-75. Cross sections were found at this website: http://www-nds.indcentre.org.in/exfor/servlet/X4sSearch5?EntryID=220070

===Cross-section===

Below is a table of the cross sections for all of the reactions of interest (Se-76 -> Se-75, Se-82 -> Se-81, and Se-80 -> Se-79).

{| border="3" cellpadding="5" cellspacing="0"
||Energy (MeV) || Se-80 -> Se-79 (mb) || Se-76 -> Se- 75 (mb) || Se-82 -> Se-81 (mb)
|-
||9.42 || ** || ** || 5.58 +/- 0.5
|-
||9.62 || ** || ** || 8.7 +/- 0.5
|-
||9.82 || ** || ** || 10.8 +/- 0.5
|-
||10.02 || 7.1 +/- 0.2 || ** || 12.4 +/- 0.7
|-
||10.22 || 10.3 +/- 0.4 ||0.4 +/- 0.2 || 15 +/- 0.9
|-
||10.42 || 12.9 +/- 0.5 || 0.8 +/- 0.3 || 15.4 +/- 0.9
|-
||10.62 || 16.2 +/- 0.5 || 4.7 +/- 0.3 || 17.3 +/- 1.1
|-
||10.82 || 19.2 +/- 0.6 || 6.6 +/- 0.4 || 21 +/- 1.1
|-
||11.02 || 22 +/- 0.6 || 9.9 +/- 0.3 || 21.8 +/- 1.4
|-
||11.22 || 23.8 +/- 1 || 12.2 +/- 0.4 || 22.5 +/- 1.9
|-
||11.42 || 28 +/- 1 || 19.5 +/- 0.5 || 27.7 +/- 1.5
|-
||11.62 || 28.6 +/- 1.2 || 23.5 +/- 0.5 || 27.8 +/- 2
|-
||11.82 || 30.4 +/- 1.5 || 26.7 +/- 0.8 || 28.4 +/- 1.8
|-
||12.02 || 33 +/- 1.4 || 32 +/- 0.8 || 31.9 +/- 1.8
|-
||12.22 || 34.9 +/- 1.8 || 36.3 +/- 0.8 || 34.5 +/- 2.4
|-
||12.42 || 37.6 +/- 1.4 || 38.8 +/- 1.4 || 38.3 +/- 2.8
|-
||12.62 || 41.5 +/- 2 || 40.9 +/- 1.4 || 42.6 +/- 3
|-
||12.82 || 43.6 +/- 2.5 || 46.7 +/- 1.6 || 41 +/- 3.2
|-
||13.02 || 46.7 +/- 2.8 || 49.2 +/- 1.8 || 48.8 +/- 2.5
|-
||13.22 || 51.9 +/- 2.6 || 55.8 +/- 1.5 || 53.3 +/- 3.4
|-
||13.42 || 56.7 +/- 1.5 || 56 +/- 2.5 || 52.7 +/- 4.3
|-
||13.62 || 61.4 +/- 2.9 || 63.6 +/- 2.3 || 60.4 +/- 3.5
|-
||13.82 || 69.5 +/- 3.3 || 69.4 +/- 2.1 || 73.3 +/- 4.1
|-
||14.02 || 78.7 +/- 4.4 || 74.4 +/- 2.9 || 78.2 +/- 4.6
|-
||14.22 || 84.9 +/- 3.6 || 78 +/- 2.8 || 82.3 +/- 4.2
|-
||14.42 || 93.3 +/- 2.7 || 87.6 +/- 3.4 || 93 +/- 4.8
|-
||14.62 || 100.5 +/- 4 || 92.2 +/- 3.1 || 99.4 +/- 4.4
|-
||14.82 || 105.1 +/- 4.6 || 96.2 +/- 3 || 110.9 +/- 3.9
|-
||15.02 || 110.9 +/- 4.6 || 101.4 +/- 3.9 || 114.7 +/- 6.1
|-
||15.22 || 118.9 +/- 4.1 || 104.9 +/- 4.3 || 124.6 +/- 5.6
|-
||15.42 || 125.8 +/- 5.5 || 108.1 +/- 5.1 || 137.5 +/- 6.7
|-
||15.62 || 132.9 +/- 4.5 || 106.8 +/- 5 || 143.7 +/- 4.6
|-
||15.82 || 132.7 +/- 5.9 || 105.4 +/- 5.6 || 140.4 +/- 5
|-
||16.02 || 127.6 +/- 5.6 || 104.8 +/- 5 || 145.69 +/- 6.9
|-
||16.22 || 132.4 +/- 5.3 || 106.6 +/- 4.9 || 151.8 +/- 6.9
|-
||16.42 || 130 +/- 7.6 || 100.5 +/- 7.5 || 143 +/- 7.4
|-
||16.62 || 125.4 +/- 6.2 || 102.6 +/- 6.2 || 137.8 +/- 6.2
|-
||16.82 || 137.4 +/- 6.7 || 100.5 +/- 7.5 || 142.8 +/- 6
|-
||17.02 || 138.1 +/- 7.5 || 101 +/- 5.9 || 132.2 +/- 7.2
|-
||17.22 || 130.4 +/- 8.3 || 93.1 +/- 6.3 || 128.8 +/- 4.7
|-
||17.42 || 114.9 +/- 6 || 95.5 +/- 6.3 || 122.7 +/- 5.9
|-
||17.62 || 110.8 +/- 6 || 94.8 +/- 8 || 120.6 +/- 6.8
|-
||17.82 || 104.4 +/- 7.4 || 99.2 +/- 7.3 || 119.2 +/- 7.2
|-
||18.02 || 108.7 +/- 6.6 || 98.1 +/- 6.2 || 115.9 +/- 7
|-
||18.22 || 102.4 +/- 7.3 || 96.3 +/- 7.3 || 112.5 +/- 5.6
|-
||18.42 || 104.3 +/- 5.7 || 98.6 +/- 7.7 || 114.1 +/- 8.2
|-
||18.62 || 104.1 +/- 5.5 || 95.5 +/- 10|| 114.1 +/- 6.5
|-
||18.82 || 91.1 +/- 7.8 || 87.2 +/- 9.1 || 90.8 +/- 7.5
|-
||19.02 || 90.5 +/- 5.5 || 88.1 +/- 7.6 || 99.4 +/- 6.3
|-
||19.22 || 85.7 +/- 6.2 || 97 +/- 9.9 || 87.2 +/- 5.9
|-
||19.42 || 91.4 +/- 6.6 || 91.7 +/- 9.2 || 90.6 +/- 7.2
|-
||19.62 || 84.9 +/- 5.6 || 83.8 +/- 10 || 81.3 +/- 6.6
|-
||19.82 || 90.3 +/- 8.1 || 71.2 +/- 8 || 83.8 +/- 6.5
|-
||20.02 || 83 +/- 5.7 || 74.4 +/- 7.7 || 80 +/- 5.9
|-
||20.22 || 79.9 +/- 6.2 || 68.8 +/- 8 || 71.1 +/- 6.4
|-
||20.42 || 67.1 +/- 7.2 || 66.6 +/- 7 || 65 +/- 7.6
|-
||20.62 || 70.9 +/- 6.6 || 59.4 +/- 7.3 || 57 +/- 5.6
|-
||20.82 || 72.2 +/- 7.6 || 70.3 +/- 6.5 || 75.2 +/- 6.7
|-
||21.02 || 66.8 +/- 6.5 || 65.8 +/- 6.4 || 61.4 +/- 7.6
|-
||21.22 || 69.7 +/- 7 || 59.9 +/- 7.2 || 73.1 +/- 6.8
|-
||21.42 || 68.2 +/- 8.4 || 59.4 +/- 7 || 59 +/- 9.3
|-
||21.62 || 68.6 +/- 7.4 || 66.2 +/- 6.8 || 67.5 +/- 6.7
|-
||21.82 || 60.9 +/- 7.3 || 68 +/- 7.2 || 55 +/- 7.2
|-
||22.02 || 58.5 +/- 7.3 || 62.1 +/- 6.5 || 55.9 +/- 8.6
|-
||22.22 || 56 +/- 7.8 || 65.3 +/- 7 || 59.4 +/- 8.1
|-
||22.42 || 69.7 +/- 7.7 || 61.6 +/- 0.4 || 64 +/- 9.7
|-
||22.62 || 60.1 +/- 8.8 || 67.7 +/- 6.2 || 67 +/- 8.2
|-
||22.82 || 60.9 +/- 8.7 || 55.7 +/- 7.8 || 55.9 +/- 8.6
|-
||23.02 || 58.8 +/- 9.3 || 57.2 +/- 6.1 || 61.4 +/- 11.2
|-
||23.22 || 50.6 +/- 9.7 || 55.2 +/- 7.7 || 48.5 +/- 8.1
|-
||23.42 || 31.5 +/- 8.7 || 44.7 +/- 8.1 || 46.5 +/- 10.1
|-
||23.62 || 37.7 +/- 8.7 || 31.3 +/- 5.9 || 34 +/- 7.1
|-
||23.82 || 29.5 +/- 10.2 || 34.7 +/- 5.9 || 47.6 +/- 10.1
|-
||24.02 || 32.4 +/- 8.6 || 33 +/- 6.3 || 43.4 +/- 10.6
|-
||24.22 || 32.8 +/- 9.6 || 21.7 +/- 7.3 || 46.2 +/- 9.5
|-
|}

Similar data can be found in the link above. Below is the plot for all the reactions of interest.

Below is a plot of 3 different isotopes of selenium with their cross sections as a function of energy.

[[File:PhotonE vs XSect.png|200px]]

Now to find the relative yields, I approximated the integral the above graph using a left hand Riemann sum with an interval width of 1 MeV and multiplied it by the natural abundance in the sample. Below is a table of the reactions and their integrated cross sections.

{| border="3" cellpadding="5" cellspacing="0"
|| Reaction || Abundance || Integrated Cross Section (mb) [10->24 MeV]
|-
|| Se-82(gamma,n)Se-81 || 8.82% || 5429.19
|-
|| Se-80(gamma,n)Se-79 || 49.8% || 5249.6
|-
|| Se-76(gamma,n)Se-75 || 9.23% || 4703.1
|}

{| border="3" cellpadding="5" cellspacing="0"
|| Reaction || Abundance || Integrated Cross Section (mb) [10->18 MeV]
|-
|| Se-82(gamma,n)Se-81 || 8.82% || 3271.3
|-
|| Se-80(gamma,n)Se-79 || 49.8% || 3090.5
|-
|| Se-76(gamma,n)Se-75 || 9.23% || 2644.7
|}

Below are the equations for the relative yield of each isotope.

<math>\frac{{76 \atop 34\; }Se (\gamma,n){75 \atop \;Se}}{{80 \atop 34\; }Se (\gamma,n){79 \atop \;Se}} = \frac{Abundance \times \int_{10.02}^{24.02}\sigma dE}{Abundance \times \int_{10.02}^{24.02}\sigma dE} = \frac{0.0923 \times 4703.1}{0.498 \times 5249.6} = 0.17 = \frac{\sigma_{Se-75}}{\sigma_{Se-79}}</math>

<math>\frac{{82 \atop 34\; }Se (\gamma,n){81 \atop \;Se}}{{80 \atop 34\; }Se (\gamma,n){79 \atop \;Se}} = \frac{Abundance \times \int_{10.02}^{24.02}\sigma dE}{Abundance \times \int_{10.02}^{24.02}\sigma dE} = \frac{0.0882 \times 5429.19}{0.498 \times 5249.6} = 0.19</math>

As of recently, the beam energy has been lowered to 18 MeV, so the relative yield for each isotope now becomes

<math>\frac{{76 \atop 34\; }Se (\gamma,n){75 \atop \;Se}}{{80 \atop 34\; }Se (\gamma,n){79 \atop \;Se}} = \frac{Abundance \times \int_{10.02}^{18.02}\sigma dE}{Abundance \times \int_{10.02}^{18.02}\sigma dE} = \frac{0.0923 \times 2644.7}{0.498 \times 3090.5} = 0.16 = \frac{\sigma_{Se-75}}{\sigma_{Se-79}}</math>

<math>\frac{{82 \atop 34\; }Se (\gamma,n){81 \atop \;Se}}{{80 \atop 34\; }Se (\gamma,n){79 \atop \;Se}} = \frac{Abundance \times \int_{10.02}^{18.02}\sigma dE}{Abundance \times \int_{10.02}^{18.02}\sigma dE} = \frac{0.0882 \times 3271.3}{0.498 \times 3090.5} = 0.18</math>

===Activity Productions===

Let

;<math>N(t)</math> = The number of activated atoms per cubic cm at time <math>t</math>
;<math>\mathcal{N}</math> =The number density of the target = <math>\frac{\rho N_A}{A}</math>[ Atoms/cm^3]
;<math>\rho</math> = material density [g/cm^3]
;<math>N_A</math> = Avagadro's number = <math>6 \times 10^{23}</math> g/mole
; <math>A</math> = Atomic Number
;<math> \phi</math> = incident photon flux ( photons/sec/cm/cm)

The rate of activated nuclei production is estimated by subtracting the rate of decay from the rate of production

<math>\frac{dN(t)}{dt} = N \sigma \phi - \lambda N(t)</math>

where

<math>\lambda</math> = half life of activated nucleus

:<math>\Rightarrow N(t) = \frac{N \sigma \phi}{\lambda}\left ( 1 - e^{-\lambda t} \right )</math>

The production rate ratio of Se-79 to Se-75 is

<math>\frac{N_{Se-79}}{N_{Se-75}} = \left ( \frac{\sigma_{Se-79}}{\sigma_{Se-75} }\right ) \left ( \frac{\lambda_{Se-75}}{\lambda_{Se-79}}\right ) = \left ( \frac{100}{15} \right ) \left ( \frac{119}{10^8} \right ) </math>
===Activity Productions===

Although the investigation of provenance will involve a comparison of isotope ratios, one will need to determine the detection limit of measuring each of those isotopes.

The amount of activated nucleii, N(t), is governed by the production rate equation below.

:<math>\Rightarrow N(t) = \frac{N \sigma \phi}{\lambda}\left ( 1 - e^{-\lambda t} \right )</math>

The number of target uncle, N, is determine using

<math>N= n_T V_T \int \sigma \phi dE</math>

<math>n_T</math> is the number of target nucleii per volume, <math>V_T</math> is the amount of volume irradiated

Our goal will be to determine <math>n_T</math>

One can use Nickel as a normalization target to remove the photon flux <math>(\phi)</math> from the integral leaving just an integral over the cross section.

[[PAA_Selenium#Can_one_perform_PAA_measurements_of_Se-82_and_Se-76.3F]]

File:4.jpg

2017-02-09T21:10:00Z

Starvale:

File:3.jpg

2017-02-09T21:09:48Z

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File:2.jpg

2017-02-09T21:09:35Z

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File:1.jpg

2017-02-09T21:09:18Z

Starvale:

SeRun 02-13-17

2017-02-09T21:09:08Z

Starvale:

[[PAA_Selenium#SeRun_02-13-17]]

=Simulations=
==Selenium Irradiation Setup for MCNP simulations:==
[[File:SeSetup.jpg | 400 px]]

==Flux==
MCNP results for photon flux through the samples (electron beam energy is 21 MeV, energy bins are 100 keV, selenium density is 4.2 g/cc, selenium sample is cylindrical, 2 cm in diameter, 2 cm in height):

The selenium disk has a diameter of 0.5 cm and a thickness of about 2 mm

[[File:PhFl.jpg| 400 px]]

==Cross-sections for various reactions (adopted from TALYS):==
[[File:CS.jpg | 400 px]]

==Production rate (1/sec) in 1 gram of natural Se (or natural Ni) assuming 22 MeV 1 microA current==

{| border="3" cellpadding="5" cellspacing="0"
| || Tube 1 || Tube 2 || Tube 3 || Tube 4
|-
| Ni-57 || 1.8x10^5 || 3.4x10^4 || 5.5x10^3 || 6.0x10^3
|-
| Se-79 || 1.5x10^6 || 2.7x10^5 || 6.2x10^4 || 6.0x10^4
|-
| Se-75 || 1.2x10^6 || 2.3x10^5 || 4.6x10^4 || 4.6x10^4
|-
| Se-80 || 1.4x10^6 || 2.4x10^5 || 5.9x10^4 || 5.6x10^4
|}

[[PAA_Selenium#SeRun_02-13-17]]

==Yields of Ni-57 and some selenium isotopes assuming 22 MeV 1 microA current:==
[[File:1.jpg | 400 px]]
[[File:2.jpg | 400 px]]
[[File:3.jpg | 400 px]]
[[File:4.jpg | 400 px]]

SeRun 02-13-17

2017-02-09T19:56:16Z

Starvale: /* Production rate in 1 gram of natural Se (or natural Ni)(1/sec) assuming 22 MeV 1 microA current */

[[PAA_Selenium#SeRun_02-13-17]]

Selenium Irradiation Setup for MCNP simulations:
[[File:SeSetup.jpg]]

MCNP results for photon flux through the samples (electron beam energy is 21 MeV, energy bins are 100 keV, selenium density is 4.2 g/cc, selenium sample is cylindrical, 2 cm in diameter, 2 cm in height):
[[File:PhFl.jpg]]

Cross-sections for various reactions (adopted from TALYS):
[[File:CS.jpg]]

=Production rate (1/sec) in 1 gram of natural Se (or natural Ni) assuming 22 MeV 1 microA current=

{| border="3" cellpadding="5" cellspacing="0"
| || Tube 1 || Tube 2 || Tube 3 || Tube 4
|-
| Ni-57 || 1.8x10^5 || 3.4x10^4 || 5.5x10^3 || 6.0x10^3
|-
| Se-79 || 1.5x10^6 || 2.7x10^5 || 6.2x10^4 || 6.0x10^4
|-
| Se-75 || 1.2x10^6 || 2.3x10^5 || 4.6x10^4 || 4.6x10^4
|-
| Se-80 || 1.4x10^6 || 2.4x10^5 || 5.9x10^4 || 5.6x10^4
|}

SeRun 02-13-17

2017-02-09T19:55:51Z

Starvale: /* Production rate in 1 gram of natural Se (or natural Ni)(1/sec) */

[[PAA_Selenium#SeRun_02-13-17]]

Selenium Irradiation Setup for MCNP simulations:
[[File:SeSetup.jpg]]

MCNP results for photon flux through the samples (electron beam energy is 21 MeV, energy bins are 100 keV, selenium density is 4.2 g/cc, selenium sample is cylindrical, 2 cm in diameter, 2 cm in height):
[[File:PhFl.jpg]]

Cross-sections for various reactions (adopted from TALYS):
[[File:CS.jpg]]

=Production rate in 1 gram of natural Se (or natural Ni)(1/sec) assuming 22 MeV 1 microA current=

{| border="3" cellpadding="5" cellspacing="0"
| || Tube 1 || Tube 2 || Tube 3 || Tube 4
|-
| Ni-57 || 1.8x10^5 || 3.4x10^4 || 5.5x10^3 || 6.0x10^3
|-
| Se-79 || 1.5x10^6 || 2.7x10^5 || 6.2x10^4 || 6.0x10^4
|-
| Se-75 || 1.2x10^6 || 2.3x10^5 || 4.6x10^4 || 4.6x10^4
|-
| Se-80 || 1.4x10^6 || 2.4x10^5 || 5.9x10^4 || 5.6x10^4
|}

SeRun 02-13-17

2017-02-09T19:41:40Z

Starvale: /* Production rate (1/sec) */

[[PAA_Selenium#SeRun_02-13-17]]

Selenium Irradiation Setup for MCNP simulations:
[[File:SeSetup.jpg]]

MCNP results for photon flux through the samples (electron beam energy is 21 MeV, energy bins are 100 keV, selenium density is 4.2 g/cc, selenium sample is cylindrical, 2 cm in diameter, 2 cm in height):
[[File:PhFl.jpg]]

Cross-sections for various reactions (adopted from TALYS):
[[File:CS.jpg]]

=Production rate in 1 gram of natural Se (or natural Ni)(1/sec)=

{| border="3" cellpadding="5" cellspacing="0"
| || Tube 1 || Tube 2 || Tube 3 || Tube 4
|-
| Ni-57 || 3.82x10^10 || 7.22x10^9 || 1.15x10^9 || 1.25x10^9
|-
| Se-79 || 3.81x10^11 || 7.05x10^10 || 1.59x10^10 || 1.54x10^10
|-
| Se-75 || 5.85x10^10 || 1.09x10^10 || 2.22x10^9 || 2.21x10^9
|-
| Se-80 || 6.19x10^10 || 1.13x10^10 || 2.67x10^9 || 2.55x10^9
|}

SeRun 02-13-17

2017-02-09T19:26:42Z

Starvale:

[[PAA_Selenium#SeRun_02-13-17]]

Selenium Irradiation Setup for MCNP simulations:
[[File:SeSetup.jpg]]

MCNP results for photon flux through the samples (electron beam energy is 21 MeV, energy bins are 100 keV, selenium density is 4.2 g/cc, selenium sample is cylindrical, 2 cm in diameter, 2 cm in height):
[[File:PhFl.jpg]]

Cross-sections for various reactions (adopted from TALYS):
[[File:CS.jpg]]

=Production rate (1/sec)=

{| border="3" cellpadding="5" cellspacing="0"
| || Tube 1 || Tube 2 || Tube 3 || Tube 4
|-
| Ni-57 || 3.82x10^10 || 7.22x10^9 || 1.15x10^9 || 1.25x10^9
|-
| Se-79 || 3.81x10^11 || 7.05x10^10 || 1.59x10^10 || 1.54x10^10
|-
| Se-75 || 5.85x10^10 || 1.09x10^10 || 2.22x10^9 || 2.21x10^9
|-
| Se-80 || 6.19x10^10 || 1.13x10^10 || 2.67x10^9 || 2.55x10^9
|}

SeRun 02-13-17

2017-02-09T19:21:30Z

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File:CS.jpg

2017-02-09T19:20:56Z

Starvale:

SeRun 02-13-17

2017-02-09T19:20:32Z

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SeRun 02-13-17

2017-02-08T15:25:51Z

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SeRun 02-13-17

2017-02-08T15:25:38Z

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SeRun 02-13-17

2017-02-08T15:24:16Z

Starvale:

File:PhFl.jpg

2017-02-08T15:22:56Z

Starvale:

SeRun 02-13-17

2017-02-08T15:22:40Z

Starvale:

[[PAA_Selenium#SeRun_02-13-17]]

Selenium Irradiation Setup for MCNP simulations:
[[File:SeSetup.jpg]]

MCNP results for photon flux through the samples:
[[File:PhFl.jpg]]

File:SeSetup.jpg

2017-02-08T14:37:35Z

Starvale: uploaded a new version of "File:SeSetup.jpg"

File:SeSetup.jpg

2017-02-08T14:36:47Z

Starvale:

SeRun 02-13-17

2017-02-08T14:36:35Z

Starvale:

[[PAA_Selenium#SeRun_02-13-17]]

Selenium Irradiation Setup for MCNP simulations:
[[File:SeSetup.jpg]]

File:Fi22.jpg

2016-12-19T13:56:33Z

Starvale:

File:Fi21.jpg

2016-12-19T13:56:14Z

Starvale:

File:Fi1.jpg

2016-12-19T13:55:46Z

Starvale:

LBE Paper

2016-12-19T13:55:27Z

Starvale: /* Liquid metal targets as an alternative= */

Liquid Lead Bismuth Target for Positron Production

=Intro=
==Need for positrons==
Intense positron sources are urgently needed for numerous applications, primarily for positron spectroscopy, which can have a huge impact on chemistry, physics, materials and biological science [1–4]. Additionally, high intensity positron beams are required to carry out gravitation experiments [5, 6] and to do chemistry with antimatter [7]. Finally, efficient positron traps also require an intense source of positrons [8, 9].

The easiest way to produce positron beams is to use e+-emitting sources, such as Na-22, which can have activity as high as 1 MBq. Another possibility is to generate positrons by pair production. In this case, an electron beam is stopped in a converter creating bremsstrahlung γ-rays. Provided that the energy of the primary electron beam is high enough, the generation probability of e-/e+ pairs is sufficiently high. Typically high Z material (such as tungsten) is preferred for positron production and moderation [10, 11]. For 10 MeV beam the optimum tungsten converter thickness is about 1.4 mm, and about 20% of the electron beam energy is converted into the x-rays.

==Conventional W target (for a 10 MeV electron beam) – power limits?==
=Liquid metal targets as an alternative==
If the electron beam power exceeds ~10 kW it is nearly impossible to cool solid metal converters properly. Such power levels require liquid metal converters, for example lead–bismuth eutectic (LBE) containing 45% of lead and 55% of bismuth. Since the liquid metal simultaneously serves as a converter and a coolant, the concerns regarding possible melting of the components of the system (primarily converter channel windows) are minimal. Both lead and bismuth have high atomic numbers and good conversion efficiency. The eutectic has a low melting point (Tmelt = 124 ºC) and quickly solidifies in the case of leakage. Such converters can withstand tens of kW.

Optimum LBE converter thickness was simulated using MCNX and G4Beamline (see Figure 1) and was found to be about 2 mm which corresponded to ~2 x 10-3 e+/e-. Momentum distribution of the positrons and electron after the 2 mm LBE converter were also simulated (see Figure 2).

[[File:Fi1.jpg]]

[[File:Fi21.jpg]]

[[File:Fi22.jpg]]

=Beam Power capability of W -vs- LBE=
==Simple 1D calculations of heat transfer and temperature gradients==
==If we can back it up with ANSYS that would be great==

=Impact of windows on positron production=
==Walls might be needed for liquid LBE – windowless design is tricky ==
==Effect of thin windows (different materials, different thickness) needs to be evaluated - by how much the production rate drops==

=Impact of LBE flow rate=
==Maximum LBE flow rate is defined by corrosion and depends on the material of the window (~ 2 m/s)==
==Limit on the flow rate means limit on the beam current and e+ production rate. ==

=Conclusions=
=References=
1. Lee KH, Yang G, Koymen AR, et al (1994) Positron annihilation induced Auger electron spectroscopy studies of submonolayer Au on Cu(100): Direct evidence for positron localization at sites containing Au atoms. Phys Rev Lett 72:1866–1869. doi: 10.1103/PhysRevLett.72.1866

2. Martin P, Strong AW, Jean P, et al (2012) Galactic annihilation emission from nucleosynthesis positrons. Astron Astrophys Vol 543, idA3, 15 pp. doi: 10.1051/0004-6361/201118721

3. Gabrielse G, Bowden NS, Oxley P, et al (2002) Background-Free Observation of Cold Antihydrogen with Field-Ionization Analysis of Its States. Phys Rev Lett 89:213401. doi: 10.1103/PhysRevLett.89.213401

4. Amoretti M, Amsler C, Bonomi G, et al (2002) Production and detection of cold antihydrogen atoms. Nature 419:456–459. doi: 10.1038/nature01096

5. Kalaydzhyan T (2016) Gravitational mass of positron from LEP synchrotron losses. Sci Rep 6:30461. doi: 10.1038/srep30461
6. Perez P, Sacquin Y, G B-LA and C, et al (2012) The GBAR experiment: gravitational behaviour of antihydrogen at rest. Class Quantum Gravity 29:184008. doi: 10.1088/0264-9381/29/18/184008

7. Green J, Lee J (1964) Positronium chemistry. Academic Press

8. Jensen K, Walker A (1990) Positron thermalization and non-thermal trapping in metals. J. Phys. Condens. Matter

9. Danielson JR, Hurst NC, Surko CM (2013) Progress towards a practical multicell positron trap. In: AIP Conf. Proc. American Institute of PhysicsAIP, pp 101–112

10. Chemerisov S, Jonah CD, Jean P KJLVAMRJPSGKTBJ and VG, et al (2011) Development of high intensity source of thermal positrons APosS (Argonne Positron Source). J Phys Conf Ser 262:012012. doi: 10.1088/1742-6596/262/1/012012

11. Abbott D, Adderley P, Adeyemi A, et al (2016) Production of highly-polarized positrons using polarized electrons at MeV energies. doi: 10.1103/PhysRevLett.116.214801

LBE Paper

2016-12-19T13:55:03Z

Starvale: /* Liquid metal targets as an alternative= */

Liquid Lead Bismuth Target for Positron Production

=Intro=
==Need for positrons==
Intense positron sources are urgently needed for numerous applications, primarily for positron spectroscopy, which can have a huge impact on chemistry, physics, materials and biological science [1–4]. Additionally, high intensity positron beams are required to carry out gravitation experiments [5, 6] and to do chemistry with antimatter [7]. Finally, efficient positron traps also require an intense source of positrons [8, 9].

The easiest way to produce positron beams is to use e+-emitting sources, such as Na-22, which can have activity as high as 1 MBq. Another possibility is to generate positrons by pair production. In this case, an electron beam is stopped in a converter creating bremsstrahlung γ-rays. Provided that the energy of the primary electron beam is high enough, the generation probability of e-/e+ pairs is sufficiently high. Typically high Z material (such as tungsten) is preferred for positron production and moderation [10, 11]. For 10 MeV beam the optimum tungsten converter thickness is about 1.4 mm, and about 20% of the electron beam energy is converted into the x-rays.

==Conventional W target (for a 10 MeV electron beam) – power limits?==
=Liquid metal targets as an alternative==
If the electron beam power exceeds ~10 kW it is nearly impossible to cool solid metal converters properly. Such power levels require liquid metal converters, for example lead–bismuth eutectic (LBE) containing 45% of lead and 55% of bismuth. Since the liquid metal simultaneously serves as a converter and a coolant, the concerns regarding possible melting of the components of the system (primarily converter channel windows) are minimal. Both lead and bismuth have high atomic numbers and good conversion efficiency. The eutectic has a low melting point (Tmelt = 124 ºC) and quickly solidifies in the case of leakage. Such converters can withstand tens of kW.

Optimum LBE converter thickness was simulated using MCNX and G4Beamline (see Figure 1) and was found to be about 2 mm which corresponded to ~2 x 10-3 e+/e-. Momentum distribution of the positrons and electron after the 2 mm LBE converter were also simulated (see Figure 2).
[[File:Fi1.jpg]]

=Beam Power capability of W -vs- LBE=
==Simple 1D calculations of heat transfer and temperature gradients==
==If we can back it up with ANSYS that would be great==

=Impact of windows on positron production=
==Walls might be needed for liquid LBE – windowless design is tricky ==
==Effect of thin windows (different materials, different thickness) needs to be evaluated - by how much the production rate drops==

=Impact of LBE flow rate=
==Maximum LBE flow rate is defined by corrosion and depends on the material of the window (~ 2 m/s)==
==Limit on the flow rate means limit on the beam current and e+ production rate. ==

=Conclusions=
=References=
1. Lee KH, Yang G, Koymen AR, et al (1994) Positron annihilation induced Auger electron spectroscopy studies of submonolayer Au on Cu(100): Direct evidence for positron localization at sites containing Au atoms. Phys Rev Lett 72:1866–1869. doi: 10.1103/PhysRevLett.72.1866

2. Martin P, Strong AW, Jean P, et al (2012) Galactic annihilation emission from nucleosynthesis positrons. Astron Astrophys Vol 543, idA3, 15 pp. doi: 10.1051/0004-6361/201118721

3. Gabrielse G, Bowden NS, Oxley P, et al (2002) Background-Free Observation of Cold Antihydrogen with Field-Ionization Analysis of Its States. Phys Rev Lett 89:213401. doi: 10.1103/PhysRevLett.89.213401

4. Amoretti M, Amsler C, Bonomi G, et al (2002) Production and detection of cold antihydrogen atoms. Nature 419:456–459. doi: 10.1038/nature01096

5. Kalaydzhyan T (2016) Gravitational mass of positron from LEP synchrotron losses. Sci Rep 6:30461. doi: 10.1038/srep30461
6. Perez P, Sacquin Y, G B-LA and C, et al (2012) The GBAR experiment: gravitational behaviour of antihydrogen at rest. Class Quantum Gravity 29:184008. doi: 10.1088/0264-9381/29/18/184008

7. Green J, Lee J (1964) Positronium chemistry. Academic Press

8. Jensen K, Walker A (1990) Positron thermalization and non-thermal trapping in metals. J. Phys. Condens. Matter

9. Danielson JR, Hurst NC, Surko CM (2013) Progress towards a practical multicell positron trap. In: AIP Conf. Proc. American Institute of PhysicsAIP, pp 101–112

10. Chemerisov S, Jonah CD, Jean P KJLVAMRJPSGKTBJ and VG, et al (2011) Development of high intensity source of thermal positrons APosS (Argonne Positron Source). J Phys Conf Ser 262:012012. doi: 10.1088/1742-6596/262/1/012012

11. Abbott D, Adderley P, Adeyemi A, et al (2016) Production of highly-polarized positrons using polarized electrons at MeV energies. doi: 10.1103/PhysRevLett.116.214801

LBE Paper

2016-12-19T13:54:41Z

Starvale: /* Liquid metal targets as an alternative= */

Liquid Lead Bismuth Target for Positron Production

=Intro=
==Need for positrons==
Intense positron sources are urgently needed for numerous applications, primarily for positron spectroscopy, which can have a huge impact on chemistry, physics, materials and biological science [1–4]. Additionally, high intensity positron beams are required to carry out gravitation experiments [5, 6] and to do chemistry with antimatter [7]. Finally, efficient positron traps also require an intense source of positrons [8, 9].

The easiest way to produce positron beams is to use e+-emitting sources, such as Na-22, which can have activity as high as 1 MBq. Another possibility is to generate positrons by pair production. In this case, an electron beam is stopped in a converter creating bremsstrahlung γ-rays. Provided that the energy of the primary electron beam is high enough, the generation probability of e-/e+ pairs is sufficiently high. Typically high Z material (such as tungsten) is preferred for positron production and moderation [10, 11]. For 10 MeV beam the optimum tungsten converter thickness is about 1.4 mm, and about 20% of the electron beam energy is converted into the x-rays.

==Conventional W target (for a 10 MeV electron beam) – power limits?==
=Liquid metal targets as an alternative==
If the electron beam power exceeds ~10 kW it is nearly impossible to cool solid metal converters properly. Such power levels require liquid metal converters, for example lead–bismuth eutectic (LBE) containing 45% of lead and 55% of bismuth. Since the liquid metal simultaneously serves as a converter and a coolant, the concerns regarding possible melting of the components of the system (primarily converter channel windows) are minimal. Both lead and bismuth have high atomic numbers and good conversion efficiency. The eutectic has a low melting point (Tmelt = 124 ºC) and quickly solidifies in the case of leakage. Such converters can withstand tens of kW.

Optimum LBE converter thickness was simulated using MCNX and G4Beamline (see Figure 1) and was found to be about 2 mm which corresponded to ~2 x 10-3 e+/e-. Momentum distribution of the positrons and electron after the 2 mm LBE converter were also simulated (see Figure 2).

=Beam Power capability of W -vs- LBE=
==Simple 1D calculations of heat transfer and temperature gradients==
==If we can back it up with ANSYS that would be great==

=Impact of windows on positron production=
==Walls might be needed for liquid LBE – windowless design is tricky ==
==Effect of thin windows (different materials, different thickness) needs to be evaluated - by how much the production rate drops==

=Impact of LBE flow rate=
==Maximum LBE flow rate is defined by corrosion and depends on the material of the window (~ 2 m/s)==
==Limit on the flow rate means limit on the beam current and e+ production rate. ==

=Conclusions=
=References=
1. Lee KH, Yang G, Koymen AR, et al (1994) Positron annihilation induced Auger electron spectroscopy studies of submonolayer Au on Cu(100): Direct evidence for positron localization at sites containing Au atoms. Phys Rev Lett 72:1866–1869. doi: 10.1103/PhysRevLett.72.1866

2. Martin P, Strong AW, Jean P, et al (2012) Galactic annihilation emission from nucleosynthesis positrons. Astron Astrophys Vol 543, idA3, 15 pp. doi: 10.1051/0004-6361/201118721

3. Gabrielse G, Bowden NS, Oxley P, et al (2002) Background-Free Observation of Cold Antihydrogen with Field-Ionization Analysis of Its States. Phys Rev Lett 89:213401. doi: 10.1103/PhysRevLett.89.213401

4. Amoretti M, Amsler C, Bonomi G, et al (2002) Production and detection of cold antihydrogen atoms. Nature 419:456–459. doi: 10.1038/nature01096

5. Kalaydzhyan T (2016) Gravitational mass of positron from LEP synchrotron losses. Sci Rep 6:30461. doi: 10.1038/srep30461
6. Perez P, Sacquin Y, G B-LA and C, et al (2012) The GBAR experiment: gravitational behaviour of antihydrogen at rest. Class Quantum Gravity 29:184008. doi: 10.1088/0264-9381/29/18/184008

7. Green J, Lee J (1964) Positronium chemistry. Academic Press

8. Jensen K, Walker A (1990) Positron thermalization and non-thermal trapping in metals. J. Phys. Condens. Matter

9. Danielson JR, Hurst NC, Surko CM (2013) Progress towards a practical multicell positron trap. In: AIP Conf. Proc. American Institute of PhysicsAIP, pp 101–112

10. Chemerisov S, Jonah CD, Jean P KJLVAMRJPSGKTBJ and VG, et al (2011) Development of high intensity source of thermal positrons APosS (Argonne Positron Source). J Phys Conf Ser 262:012012. doi: 10.1088/1742-6596/262/1/012012

11. Abbott D, Adderley P, Adeyemi A, et al (2016) Production of highly-polarized positrons using polarized electrons at MeV energies. doi: 10.1103/PhysRevLett.116.214801

LBE Paper

2016-12-19T13:53:24Z

Starvale: /* Liquid metal targets as an alternative= */

Liquid Lead Bismuth Target for Positron Production

=Intro=
==Need for positrons==
Intense positron sources are urgently needed for numerous applications, primarily for positron spectroscopy, which can have a huge impact on chemistry, physics, materials and biological science [1–4]. Additionally, high intensity positron beams are required to carry out gravitation experiments [5, 6] and to do chemistry with antimatter [7]. Finally, efficient positron traps also require an intense source of positrons [8, 9].

The easiest way to produce positron beams is to use e+-emitting sources, such as Na-22, which can have activity as high as 1 MBq. Another possibility is to generate positrons by pair production. In this case, an electron beam is stopped in a converter creating bremsstrahlung γ-rays. Provided that the energy of the primary electron beam is high enough, the generation probability of e-/e+ pairs is sufficiently high. Typically high Z material (such as tungsten) is preferred for positron production and moderation [10, 11]. For 10 MeV beam the optimum tungsten converter thickness is about 1.4 mm, and about 20% of the electron beam energy is converted into the x-rays.

==Conventional W target (for a 10 MeV electron beam) – power limits?==
=Liquid metal targets as an alternative==
If the electron beam power exceeds ~10 kW it is nearly impossible to cool solid metal converters properly. Such power levels require liquid metal converters, for example lead–bismuth eutectic (LBE) containing 45% of lead and 55% of bismuth. Since the liquid metal simultaneously serves as a converter and a coolant, the concerns regarding possible melting of the components of the system (primarily converter channel windows) are minimal. Both lead and bismuth have high atomic numbers and good conversion efficiency. The eutectic has a low melting point (Tmelt = 124 ºC) and quickly solidifies in the case of leakage. Such converters can withstand tens of kW.

Optimum LBE converter thickness was simulated using MCNX and G4Beamline (see Figure 1) and was found to be about 2 mm which corresponded to ~2 x 10-3 e+/e-. Momentum distribution of the positrons and electron after the 2 mm LBE converter were also simulated (see Figure 2).
[[File:Example.jpg]]
[[File:Example.jpg]]
[[File:Example.jpg]]

=Beam Power capability of W -vs- LBE=
==Simple 1D calculations of heat transfer and temperature gradients==
==If we can back it up with ANSYS that would be great==

=Impact of windows on positron production=
==Walls might be needed for liquid LBE – windowless design is tricky ==
==Effect of thin windows (different materials, different thickness) needs to be evaluated - by how much the production rate drops==

=Impact of LBE flow rate=
==Maximum LBE flow rate is defined by corrosion and depends on the material of the window (~ 2 m/s)==
==Limit on the flow rate means limit on the beam current and e+ production rate. ==

=Conclusions=
=References=
1. Lee KH, Yang G, Koymen AR, et al (1994) Positron annihilation induced Auger electron spectroscopy studies of submonolayer Au on Cu(100): Direct evidence for positron localization at sites containing Au atoms. Phys Rev Lett 72:1866–1869. doi: 10.1103/PhysRevLett.72.1866

2. Martin P, Strong AW, Jean P, et al (2012) Galactic annihilation emission from nucleosynthesis positrons. Astron Astrophys Vol 543, idA3, 15 pp. doi: 10.1051/0004-6361/201118721

3. Gabrielse G, Bowden NS, Oxley P, et al (2002) Background-Free Observation of Cold Antihydrogen with Field-Ionization Analysis of Its States. Phys Rev Lett 89:213401. doi: 10.1103/PhysRevLett.89.213401

4. Amoretti M, Amsler C, Bonomi G, et al (2002) Production and detection of cold antihydrogen atoms. Nature 419:456–459. doi: 10.1038/nature01096

5. Kalaydzhyan T (2016) Gravitational mass of positron from LEP synchrotron losses. Sci Rep 6:30461. doi: 10.1038/srep30461
6. Perez P, Sacquin Y, G B-LA and C, et al (2012) The GBAR experiment: gravitational behaviour of antihydrogen at rest. Class Quantum Gravity 29:184008. doi: 10.1088/0264-9381/29/18/184008

7. Green J, Lee J (1964) Positronium chemistry. Academic Press

8. Jensen K, Walker A (1990) Positron thermalization and non-thermal trapping in metals. J. Phys. Condens. Matter

9. Danielson JR, Hurst NC, Surko CM (2013) Progress towards a practical multicell positron trap. In: AIP Conf. Proc. American Institute of PhysicsAIP, pp 101–112

10. Chemerisov S, Jonah CD, Jean P KJLVAMRJPSGKTBJ and VG, et al (2011) Development of high intensity source of thermal positrons APosS (Argonne Positron Source). J Phys Conf Ser 262:012012. doi: 10.1088/1742-6596/262/1/012012

11. Abbott D, Adderley P, Adeyemi A, et al (2016) Production of highly-polarized positrons using polarized electrons at MeV energies. doi: 10.1103/PhysRevLett.116.214801

LBE Paper

2016-12-19T13:52:03Z

Starvale: /* Liquid metal targets as an alternative= */

Liquid Lead Bismuth Target for Positron Production

=Intro=
==Need for positrons==
Intense positron sources are urgently needed for numerous applications, primarily for positron spectroscopy, which can have a huge impact on chemistry, physics, materials and biological science [1–4]. Additionally, high intensity positron beams are required to carry out gravitation experiments [5, 6] and to do chemistry with antimatter [7]. Finally, efficient positron traps also require an intense source of positrons [8, 9].

The easiest way to produce positron beams is to use e+-emitting sources, such as Na-22, which can have activity as high as 1 MBq. Another possibility is to generate positrons by pair production. In this case, an electron beam is stopped in a converter creating bremsstrahlung γ-rays. Provided that the energy of the primary electron beam is high enough, the generation probability of e-/e+ pairs is sufficiently high. Typically high Z material (such as tungsten) is preferred for positron production and moderation [10, 11]. For 10 MeV beam the optimum tungsten converter thickness is about 1.4 mm, and about 20% of the electron beam energy is converted into the x-rays.

==Conventional W target (for a 10 MeV electron beam) – power limits?==
=Liquid metal targets as an alternative==
If the electron beam power exceeds ~10 kW it is nearly impossible to cool solid metal converters properly. Such power levels require liquid metal converters, for example lead–bismuth eutectic (LBE) containing 45% of lead and 55% of bismuth. Since the liquid metal simultaneously serves as a converter and a coolant, the concerns regarding possible melting of the components of the system (primarily converter channel windows) are minimal. Both lead and bismuth have high atomic numbers and good conversion efficiency. The eutectic has a low melting point (Tmelt = 124 ºC) and quickly solidifies in the case of leakage. Such converters can withstand tens of kW.

Optimum LBE converter thickness was simulated using MCNX and G4Beamline (see Figure 1) and was found to be about 2 mm which corresponded to ~2 x 10-3 e+/e-. Momentum distribution of the positrons and electron after the 2 mm LBE converter were also simulated (see Figure 2).

=Beam Power capability of W -vs- LBE=
==Simple 1D calculations of heat transfer and temperature gradients==
==If we can back it up with ANSYS that would be great==

=Impact of windows on positron production=
==Walls might be needed for liquid LBE – windowless design is tricky ==
==Effect of thin windows (different materials, different thickness) needs to be evaluated - by how much the production rate drops==

=Impact of LBE flow rate=
==Maximum LBE flow rate is defined by corrosion and depends on the material of the window (~ 2 m/s)==
==Limit on the flow rate means limit on the beam current and e+ production rate. ==

=Conclusions=
=References=
1. Lee KH, Yang G, Koymen AR, et al (1994) Positron annihilation induced Auger electron spectroscopy studies of submonolayer Au on Cu(100): Direct evidence for positron localization at sites containing Au atoms. Phys Rev Lett 72:1866–1869. doi: 10.1103/PhysRevLett.72.1866

2. Martin P, Strong AW, Jean P, et al (2012) Galactic annihilation emission from nucleosynthesis positrons. Astron Astrophys Vol 543, idA3, 15 pp. doi: 10.1051/0004-6361/201118721

3. Gabrielse G, Bowden NS, Oxley P, et al (2002) Background-Free Observation of Cold Antihydrogen with Field-Ionization Analysis of Its States. Phys Rev Lett 89:213401. doi: 10.1103/PhysRevLett.89.213401

4. Amoretti M, Amsler C, Bonomi G, et al (2002) Production and detection of cold antihydrogen atoms. Nature 419:456–459. doi: 10.1038/nature01096

5. Kalaydzhyan T (2016) Gravitational mass of positron from LEP synchrotron losses. Sci Rep 6:30461. doi: 10.1038/srep30461
6. Perez P, Sacquin Y, G B-LA and C, et al (2012) The GBAR experiment: gravitational behaviour of antihydrogen at rest. Class Quantum Gravity 29:184008. doi: 10.1088/0264-9381/29/18/184008

7. Green J, Lee J (1964) Positronium chemistry. Academic Press

8. Jensen K, Walker A (1990) Positron thermalization and non-thermal trapping in metals. J. Phys. Condens. Matter

9. Danielson JR, Hurst NC, Surko CM (2013) Progress towards a practical multicell positron trap. In: AIP Conf. Proc. American Institute of PhysicsAIP, pp 101–112

10. Chemerisov S, Jonah CD, Jean P KJLVAMRJPSGKTBJ and VG, et al (2011) Development of high intensity source of thermal positrons APosS (Argonne Positron Source). J Phys Conf Ser 262:012012. doi: 10.1088/1742-6596/262/1/012012

11. Abbott D, Adderley P, Adeyemi A, et al (2016) Production of highly-polarized positrons using polarized electrons at MeV energies. doi: 10.1103/PhysRevLett.116.214801

LBE Paper

2016-12-19T13:51:23Z

Starvale: /* References */

Liquid Lead Bismuth Target for Positron Production

=Intro=
==Need for positrons==
Intense positron sources are urgently needed for numerous applications, primarily for positron spectroscopy, which can have a huge impact on chemistry, physics, materials and biological science [1–4]. Additionally, high intensity positron beams are required to carry out gravitation experiments [5, 6] and to do chemistry with antimatter [7]. Finally, efficient positron traps also require an intense source of positrons [8, 9].

The easiest way to produce positron beams is to use e+-emitting sources, such as Na-22, which can have activity as high as 1 MBq. Another possibility is to generate positrons by pair production. In this case, an electron beam is stopped in a converter creating bremsstrahlung γ-rays. Provided that the energy of the primary electron beam is high enough, the generation probability of e-/e+ pairs is sufficiently high. Typically high Z material (such as tungsten) is preferred for positron production and moderation [10, 11]. For 10 MeV beam the optimum tungsten converter thickness is about 1.4 mm, and about 20% of the electron beam energy is converted into the x-rays.

==Conventional W target (for a 10 MeV electron beam) – power limits?==
=Liquid metal targets as an alternative==

=Beam Power capability of W -vs- LBE=
==Simple 1D calculations of heat transfer and temperature gradients==
==If we can back it up with ANSYS that would be great==

=Impact of windows on positron production=
==Walls might be needed for liquid LBE – windowless design is tricky ==
==Effect of thin windows (different materials, different thickness) needs to be evaluated - by how much the production rate drops==

=Impact of LBE flow rate=
==Maximum LBE flow rate is defined by corrosion and depends on the material of the window (~ 2 m/s)==
==Limit on the flow rate means limit on the beam current and e+ production rate. ==

=Conclusions=
=References=
1. Lee KH, Yang G, Koymen AR, et al (1994) Positron annihilation induced Auger electron spectroscopy studies of submonolayer Au on Cu(100): Direct evidence for positron localization at sites containing Au atoms. Phys Rev Lett 72:1866–1869. doi: 10.1103/PhysRevLett.72.1866

2. Martin P, Strong AW, Jean P, et al (2012) Galactic annihilation emission from nucleosynthesis positrons. Astron Astrophys Vol 543, idA3, 15 pp. doi: 10.1051/0004-6361/201118721

3. Gabrielse G, Bowden NS, Oxley P, et al (2002) Background-Free Observation of Cold Antihydrogen with Field-Ionization Analysis of Its States. Phys Rev Lett 89:213401. doi: 10.1103/PhysRevLett.89.213401

4. Amoretti M, Amsler C, Bonomi G, et al (2002) Production and detection of cold antihydrogen atoms. Nature 419:456–459. doi: 10.1038/nature01096

5. Kalaydzhyan T (2016) Gravitational mass of positron from LEP synchrotron losses. Sci Rep 6:30461. doi: 10.1038/srep30461
6. Perez P, Sacquin Y, G B-LA and C, et al (2012) The GBAR experiment: gravitational behaviour of antihydrogen at rest. Class Quantum Gravity 29:184008. doi: 10.1088/0264-9381/29/18/184008

7. Green J, Lee J (1964) Positronium chemistry. Academic Press

8. Jensen K, Walker A (1990) Positron thermalization and non-thermal trapping in metals. J. Phys. Condens. Matter

9. Danielson JR, Hurst NC, Surko CM (2013) Progress towards a practical multicell positron trap. In: AIP Conf. Proc. American Institute of PhysicsAIP, pp 101–112

10. Chemerisov S, Jonah CD, Jean P KJLVAMRJPSGKTBJ and VG, et al (2011) Development of high intensity source of thermal positrons APosS (Argonne Positron Source). J Phys Conf Ser 262:012012. doi: 10.1088/1742-6596/262/1/012012

11. Abbott D, Adderley P, Adeyemi A, et al (2016) Production of highly-polarized positrons using polarized electrons at MeV energies. doi: 10.1103/PhysRevLett.116.214801

LBE Paper

2016-12-19T13:50:41Z

Starvale: /* References */

Liquid Lead Bismuth Target for Positron Production

=Intro=
==Need for positrons==
Intense positron sources are urgently needed for numerous applications, primarily for positron spectroscopy, which can have a huge impact on chemistry, physics, materials and biological science [1–4]. Additionally, high intensity positron beams are required to carry out gravitation experiments [5, 6] and to do chemistry with antimatter [7]. Finally, efficient positron traps also require an intense source of positrons [8, 9].

The easiest way to produce positron beams is to use e+-emitting sources, such as Na-22, which can have activity as high as 1 MBq. Another possibility is to generate positrons by pair production. In this case, an electron beam is stopped in a converter creating bremsstrahlung γ-rays. Provided that the energy of the primary electron beam is high enough, the generation probability of e-/e+ pairs is sufficiently high. Typically high Z material (such as tungsten) is preferred for positron production and moderation [10, 11]. For 10 MeV beam the optimum tungsten converter thickness is about 1.4 mm, and about 20% of the electron beam energy is converted into the x-rays.

==Conventional W target (for a 10 MeV electron beam) – power limits?==
=Liquid metal targets as an alternative==

=Beam Power capability of W -vs- LBE=
==Simple 1D calculations of heat transfer and temperature gradients==
==If we can back it up with ANSYS that would be great==

=Impact of windows on positron production=
==Walls might be needed for liquid LBE – windowless design is tricky ==
==Effect of thin windows (different materials, different thickness) needs to be evaluated - by how much the production rate drops==

=Impact of LBE flow rate=
==Maximum LBE flow rate is defined by corrosion and depends on the material of the window (~ 2 m/s)==
==Limit on the flow rate means limit on the beam current and e+ production rate. ==

=Conclusions=
=References=
1. Lee KH, Yang G, Koymen AR, et al (1994) Positron annihilation induced Auger electron spectroscopy studies of submonolayer Au on Cu(100): Direct evidence for positron localization at sites containing Au atoms. Phys Rev Lett 72:1866–1869. doi: 10.1103/PhysRevLett.72.1866/
2. Martin P, Strong AW, Jean P, et al (2012) Galactic annihilation emission from nucleosynthesis positrons. Astron Astrophys Vol 543, idA3, 15 pp. doi: 10.1051/0004-6361/201118721
3. Gabrielse G, Bowden NS, Oxley P, et al (2002) Background-Free Observation of Cold Antihydrogen with Field-Ionization Analysis of Its States. Phys Rev Lett 89:213401. doi: 10.1103/PhysRevLett.89.213401
4. Amoretti M, Amsler C, Bonomi G, et al (2002) Production and detection of cold antihydrogen atoms. Nature 419:456–459. doi: 10.1038/nature01096
5. Kalaydzhyan T (2016) Gravitational mass of positron from LEP synchrotron losses. Sci Rep 6:30461. doi: 10.1038/srep30461
6. Perez P, Sacquin Y, G B-LA and C, et al (2012) The GBAR experiment: gravitational behaviour of antihydrogen at rest. Class Quantum Gravity 29:184008. doi: 10.1088/0264-9381/29/18/184008
7. Green J, Lee J (1964) Positronium chemistry. Academic Press
8. Jensen K, Walker A (1990) Positron thermalization and non-thermal trapping in metals. J. Phys. Condens. Matter
9. Danielson JR, Hurst NC, Surko CM (2013) Progress towards a practical multicell positron trap. In: AIP Conf. Proc. American Institute of PhysicsAIP, pp 101–112
10. Chemerisov S, Jonah CD, Jean P KJLVAMRJPSGKTBJ and VG, et al (2011) Development of high intensity source of thermal positrons APosS (Argonne Positron Source). J Phys Conf Ser 262:012012. doi: 10.1088/1742-6596/262/1/012012
11. Abbott D, Adderley P, Adeyemi A, et al (2016) Production of highly-polarized positrons using polarized electrons at MeV energies. doi: 10.1103/PhysRevLett.116.214801

LBE Paper

2016-12-19T13:50:03Z

Starvale: /* References */

Liquid Lead Bismuth Target for Positron Production

=Intro=
==Need for positrons==
Intense positron sources are urgently needed for numerous applications, primarily for positron spectroscopy, which can have a huge impact on chemistry, physics, materials and biological science [1–4]. Additionally, high intensity positron beams are required to carry out gravitation experiments [5, 6] and to do chemistry with antimatter [7]. Finally, efficient positron traps also require an intense source of positrons [8, 9].

The easiest way to produce positron beams is to use e+-emitting sources, such as Na-22, which can have activity as high as 1 MBq. Another possibility is to generate positrons by pair production. In this case, an electron beam is stopped in a converter creating bremsstrahlung γ-rays. Provided that the energy of the primary electron beam is high enough, the generation probability of e-/e+ pairs is sufficiently high. Typically high Z material (such as tungsten) is preferred for positron production and moderation [10, 11]. For 10 MeV beam the optimum tungsten converter thickness is about 1.4 mm, and about 20% of the electron beam energy is converted into the x-rays.

==Conventional W target (for a 10 MeV electron beam) – power limits?==
=Liquid metal targets as an alternative==

=Beam Power capability of W -vs- LBE=
==Simple 1D calculations of heat transfer and temperature gradients==
==If we can back it up with ANSYS that would be great==

=Impact of windows on positron production=
==Walls might be needed for liquid LBE – windowless design is tricky ==
==Effect of thin windows (different materials, different thickness) needs to be evaluated - by how much the production rate drops==

=Impact of LBE flow rate=
==Maximum LBE flow rate is defined by corrosion and depends on the material of the window (~ 2 m/s)==
==Limit on the flow rate means limit on the beam current and e+ production rate. ==

=Conclusions=
=References=
1. Lee KH, Yang G, Koymen AR, et al (1994) Positron annihilation induced Auger electron spectroscopy studies of submonolayer Au on Cu(100): Direct evidence for positron localization at sites containing Au atoms. Phys Rev Lett 72:1866–1869. doi: 10.1103/PhysRevLett.72.1866
2. Martin P, Strong AW, Jean P, et al (2012) Galactic annihilation emission from nucleosynthesis positrons. Astron Astrophys Vol 543, idA3, 15 pp. doi: 10.1051/0004-6361/201118721
3. Gabrielse G, Bowden NS, Oxley P, et al (2002) Background-Free Observation of Cold Antihydrogen with Field-Ionization Analysis of Its States. Phys Rev Lett 89:213401. doi: 10.1103/PhysRevLett.89.213401
4. Amoretti M, Amsler C, Bonomi G, et al (2002) Production and detection of cold antihydrogen atoms. Nature 419:456–459. doi: 10.1038/nature01096
5. Kalaydzhyan T (2016) Gravitational mass of positron from LEP synchrotron losses. Sci Rep 6:30461. doi: 10.1038/srep30461
6. Perez P, Sacquin Y, G B-LA and C, et al (2012) The GBAR experiment: gravitational behaviour of antihydrogen at rest. Class Quantum Gravity 29:184008. doi: 10.1088/0264-9381/29/18/184008
7. Green J, Lee J (1964) Positronium chemistry. Academic Press
8. Jensen K, Walker A (1990) Positron thermalization and non-thermal trapping in metals. J. Phys. Condens. Matter
9. Danielson JR, Hurst NC, Surko CM (2013) Progress towards a practical multicell positron trap. In: AIP Conf. Proc. American Institute of PhysicsAIP, pp 101–112
10. Chemerisov S, Jonah CD, Jean P KJLVAMRJPSGKTBJ and VG, et al (2011) Development of high intensity source of thermal positrons APosS (Argonne Positron Source). J Phys Conf Ser 262:012012. doi: 10.1088/1742-6596/262/1/012012
11. Abbott D, Adderley P, Adeyemi A, et al (2016) Production of highly-polarized positrons using polarized electrons at MeV energies. doi: 10.1103/PhysRevLett.116.214801

LBE Paper

2016-12-19T13:49:38Z

Starvale: /* Need for positrons */

PAA Selenium

2016-09-07T12:34:13Z

Starvale: /* Can one use plant material to measure the provenance of selenium? */

Using PAA ro measure Selenium concentrations.

According to Krouse<ref name="Krous1962"> H.R. Krause and H.G. Thode,"Thermodynamic Properties and Geochemistry of Iosotopic Compounds of Selenium",.Can. J. Chem., vol 40, pg 367</ref>
, the fractional concentration of Se-82/Se-76 in plant material is observed to be less than from primordial (meteoric) concentrations by as much as 1.2%. Anaerobic bacteria are known to reduce selenates and senelites in biological systems. This may be the reason plant material has fractionation of selenium isotopes. They also observe excess concentrations of up to 0.4% in soil.

Plant material appears to detect environmental selenium.

=Can one use plant material to measure the provenance of selenium?=

Natural abundance of selenium

{| border="3" cellpadding="5" cellspacing="0"
| Isotope|| Abundance
|-
| Se-74 || 0.86%
|-
| Se-76 || 9.23%
|-
| Se-77 || 7.60%
|-
| Se-78 || 23.69%
|-
| Se-80 || 49.80%
|-
| Se-82 || 8.82%
|}

Possible reactions

{| border="3" cellpadding="5" cellspacing="0"
| Reaction|| Half-life ||Relative activity ||Gamma-rays, keV (BR)
|-
| Se-74(gamma,n)Se-73 || 7.1 h || 1.5E-1 || 361 (100)
|-
| Se-74(gamma,n)Se-73m || 39 m || 3.2 || 402 (4)
|-
| Se-74(gamma,np)As-72 || 26 h || 1.0E-3 || 834 (100)
|-
| Se-76(gamma,n)Se-75 || 120 d || 1.3E-2 || 265(29)
|-
| Se-77(gamma,p)As-76 || 26.4 h || 4.4E-2 || 559(44)
|-
| Se-78(gamma,p)As-77 || 38.8 h || 8.6E-2 || 239(2)
|-
| Se-80(gamma,n)Se-79m || 3.9 m || 5.9 || 96(10)
|-
| Se-80(gamma,np)As-78 || 1.5 h || 2.2E-2 || 614(54)
|-
| Se-80(gamma,p)As-79 || 8.2 m || 1.3 || 96(9)
|-
| Se-80(gamma,<math>a</math>p)Ge-75 || 83 m || 2.8E-1 || 265(11)
|-
|}

=Can one perform PAA measurements of Se-82 and Se-76?=

==Neutron knockout of Se-82==
If you knock a neutron out of Se-82 you produce the unstable isotope Se-81 which Beta emitts with half life of 18 min and a meta-state that emmits a 103 keV gamma with a 57 minute half life.

<math>{82 \atop 34\; }Se (\gamma,n){81 \atop \; }Se</math>

Other prominent photons

260 & 276 keV for the 57 minute half life isotope

==Neutron knockout of Se-76==
If you knock a neutron out of Se-76 you produce the unstable isotope Se-75 which has a half life of 119 days.

<math>{76 \atop\; }Se (\gamma,n){75 \atop \; }Se</math>

The prominent photons emitted have the following energies

136, 264, and 279 keV

The article below describes how plant material and soil contain Se-76 to Se-82 ratios that differ from other natural samples by 1.5%. They argue that it is due to the bacteria living in plant material.

[[File:Krouse_CanJournChem_40_1962_p367.pdf]]

Plant material is a natural way to sample the selenium content to determine if there are difference isotopic ratios due to the impact of human activities on the environment.

=Experiments=

==Chlorine==

It looks like Cl-35 is abundant as you see photon energies of 146 keV and 2127 keV (you can barely see 1176 keV) from Cl-34's decay (neutron knocked out of Cl-35).

The half life is 32 minutes.

Should check the half life from the run AccOnAlInDetASe-AinDetD_001.root using the calibration

MPA->Draw("0.18063+0.960133*evt.Chan>> SeRun_008(8000,0.5,8000.5)","evt.ADCid==3");

== Irradiation of Horse Mineral Supplement==

Below is the EMSL report for the horse feed sample.
https://wiki.iac.isu.edu/index.php/File:EMSL_Report_Horse_Feed.pdf

=== Chlorine is a dominant signal===

First, look at the peak around 146 keV
[[File:146_keV.png | 200 px]]

Next I plotted the counts as a function of time to get an exponentially decaying graph. When doing an exponential fit here, the parameter "b" given by root will be the decay constant.

[[ File:Chlorine.png | 200 px]]

Root gives a half life of 32.9508 +/- 0.01 minutes

Now do the same for the 2127 keV line
[[File:2127_keV.png | 200 px]]

Here are the counts plotted as a function of time
[[File:2127.png | 200 px ]]

Root gives a half life of 35.3962 +/- 0.2 minutes

=== Potassium is a potential signal ===

Looking at the spectrum for the fast irradiation sample, there are 2 prominent lines that could be from 38-K. The mechanism would be a single neutron knockout from a stable 39-K nucleus. The two most dominant energies of the three for 38-K are 2167 keV and 3936 keV and the half life is 7.63 minutes. Below is a fit to the energy spectrum histogram

[[File:2168_peak.png | 200 px]]

Now check the half life

[[File:2167.png | 200 px]]

Root gives a half life of 8.03 +/- 0.02 minutes

Next check the 3936 peak

[[File: 3937_Peak.png | 200 px ]]

and check the half life

[[File: 3936_keV_halflife.png | 200 px ]]

Root gives a value for b = - 1.14372x10^(-3), which in turn gives a half life of 10.1 minutes

It seems very possible that 38-K could be in the sample of horse feed.

== First Observation of Se lines==

Using the 44 Machine at 7 kW power and 44 meV incident electron energy to produce a bremsstrahlung spectrum with a mean energy of 15 meV.

All runs lasting less than 214 seconds have time stamp that gives real time if you divide by clock frequency of 20 MHz. The first 32 bits are used for a real time measurement.

== Detector Efficiency ==

Below is the runlist for finding the efficiency of the detector at position R

{| border="3" cellpadding="5" cellspacing="0"
| Source || Serial # || Reference Date || Activity || Start || Stop || Live
|-
| Na-22 || 129743 || 7-01-08 || 9.427 microCi || 15:49 || 16:19 || 1796.803
|-
| Cs-137 || 129793 || 7-01-08 || 1.006 microCi || 14:25 || 14:56 || 1879.606
|-
| Mn-54 || 129807 || 7-01-08 || 11.77 microCi || 15:00 || 15:30 || 1793.420
|-
| Co-60 || 129740 || 7-01-08 || 10.42 microCi || 15:33 || 15:43 || 569.725
|-
|}

Below are the theoretical calculations for the theoretical decay frequencies

Na-22, 9.427micro Ci on July 1, 2008, half life 2.602 +/- 0.002 years, 99.937% for 1274.52 and 178.8 for 511 line , activity in March 31, 2016 =1.196micro Ci
:= <math>\left (0.99937 \right )\left ( 1.196 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 44,224 Hz </math> for the 1274 line

:= <math>\left (1.788 \right )\left ( 1.196 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 79122.6 Hz </math> for the 511 line

Cs-137, 661.660 line, 85.21% * 1.066micro Ci on July 1, 2008, half life 30.0 +/- 0.2 yrs, March 31, 2016 activity = 0.891micro Ci expected rate for 661 line

:= <math>\left (0.8521 \right )\left ( 0.891 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 28091.2 Hz </math>

Mn-54, 11.77 microCi on July 1, 2008, half life =312.20 +/- 0.07 days, 99.975% intensity on 834.826 , March 31, 2016 activity =0.02328micro Ci

:= <math>\left (0.99975 \right )\left ( 0.02328 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 861.1 Hz </math> for the 834 line

Co-60, 10.42micro Ci July 1, 2008, half life 5.271 +/- 0.001 years, 99.0 % for 1173.237 and 99.9824 % for 1332.501, March 31, 2016 activity=3.759micro Ci

:= <math>\left (0.99 \right )\left ( 3.759 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 137692.17 Hz </math> for the 1173 line

:= <math>\left (0.999824 \right )\left ( 3.759 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 139058.52 Hz </math> for the 1332 line

Below is a table where the actual efficiency will be calculated for position R (farthest position).

{| border="3" cellpadding="5" cellspacing="0"
| Run || Source || Energy (keV) || Expected Rate (Hz) || HpGe Rate (Hz) || HpGe Det D Efficiency (%)
|-
| Eff_003 || Na-22 || 511 || 79122.6 || (506:516) (4.309-0.065=4.244) || 0.005
|-
| Eff_005 || Cs-137 || 661.657 || 28091.2 ||(657:666)(1.105-0.02281=1.0821) ||0.004
|-
| Eff_006 || Mn-54 || 834.848 || 861.1 ||(830:839)(0.04037-0.009123=0.031247)||0.004
|-
| Eff_007 || Co-60 || 1173.228 || 137692 ||(1164:1182)(3.686-0.01939=3.67)||0.003
|-
| Eff_003 || Na-22 || 1274.537 || 44224 ||(1270:1279) (1.073-0.0057=1.0673)||0.002
|-
| Eff_007 || Co-60 || 1332.492 || 139058.52 ||(1328:1337)(3.283-0.05702=3.22598)|| 0.002
|}

Below is a runlist for position k

{| border="3" cellpadding="5" cellspacing="0"
| Source || Serial # || Reference Date || Activity || Start || Stop || Live
|-
| Na-22 || 129743 || 7-01-08 || 9.427 microCi || 14:54 || 15:01 || 434.087
|-
| Cs-137 || 129793 || 7-01-08 || 1.006 microCi || 15:48 || 15:55 || 413.925
|-
| Mn-54 || 129807 || 7-01-08 || 11.77 microCi || 15:28 || 15:40 || 705.186
|-
| Co-60 || 129740 || 7-01-08 || 10.42 microCi || 15:41 || 15:47 || 346.092
|-
|}

Below are the theoretical decay frequencies

Na-22, 9.427micro Ci on July 1, 2008, half life 2.602 +/- 0.002 years, 99.937% for 1274.52 and 178.8 for 511 line , activity in April 14, 2016 =1.183micro Ci
:= <math>\left (0.99937 \right )\left ( 1.183 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 43743.4 Hz </math> for the 1274 line

:= <math>\left (1.788 \right )\left ( 1.183 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 78262.5 Hz </math> for the 511 line

Cs-137, 661.660 line, 85.21% * 1.066micro Ci on July 1, 2008, half life 30.0 +/- 0.2 yrs, April 14, 2016 activity =0.890 micro Ci expected rate for 661 line

:= <math>\left (0.8521 \right )\left ( 0.890 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 28059.7 Hz </math>

Mn-54, 11.77 on July 1, 2008, half life =312.20 +/- 0.07 days, 99.975% intensity on 834.826 , April 14, 2016 activity =0.02251micro Ci

:= <math>\left (0.99975 \right )\left ( 0.02251 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 830.79 Hz </math> for the 834 line

Co-60, 10.42micro Ci July 1, 2008, half life 5.271 +/- 0.001 years, 99.0 % for 1173.237 and 99.9824 % for 1332.501, April 14, 2016 activity=3.74micro Ci

:= <math>\left (0.99 \right )\left ( 3.74 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 136996.2 Hz </math> for the 1173 line

:= <math>\left (0.999824 \right )\left ( 3.74 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 138355.6 Hz </math> for the 1332 line

Below are the actual efficiencies for position k

{| border="3" cellpadding="5" cellspacing="0"
| Run || Source || Energy (keV) || Expected Rate (Hz) || HpGe Rate (Hz) || HpGe Det D Efficiency (%)
|-
| Eff_k_002 || Na-22 || 511 || 79122.6 || (506:516)(49.21-0.6272=48.58) || 0.06
|-
| Eff_k_006 || Cs-137 || 661.657 || 28091.2 ||(657:666)(12.86-0.02281=12.837) ||0.05
|-
| Eff_k_004 || Mn-54 || 834.848 || 861.1 ||(830:839)(0.3204-0.009123=0.311)||0.04
|-
| Eff_k_005 || Co-60 || 1173.228 || 137692 ||(1164:1182)(42.39-0.02053=42.369)||0.03
|-
| Eff_k_002 || Na-22 || 1274.537 || 44224 ||(1270:1279) (12.53-0.005702)=12.52||0.03
|-
| Eff_k_005 || Co-60 || 1332.492 || 139058.52 ||(1328:1337)(35.94-0.005072)|| 0.03
|}

Below is a runlist for position C

{| border="3" cellpadding="5" cellspacing="0"
| Source || Serial # || Reference Date || Activity || Start || Stop || Live
|-
| Na-22 || 129742 || 7-01-08 || 1.146 microCi || 12:55 || 12:57 || 129.782
|-
| Cs-137 || 129793 || 7-01-08 || 1.006 microCi || 13:02 || 13:04 || 123.818
|-
| Mn-54 || 129806 || 7-01-08 || 1.226 microCi || 13:11 || 13:21 || 613.754
|-
| Co-60 || 129739 || 7-01-08 || 1.082 microCi || 13:08 || 13:09 || 103.599
|-
|}

Below are the calculations for the theoretical frequencies

Na-22, 9.427micro Ci on July 1, 2008, half life 2.602 +/- 0.002 years, 99.937% for 1274.52 and 178.8 for 511 line , activity in May 5, 2016 =1.196micro Ci
:= <math>\left (0.99937 \right )\left ( 0.14 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 5176.7 Hz </math> for the 1274 line

:= <math>\left (1.788 \right )\left ( 0.14 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 9261.8 Hz </math> for the 511 line

Cs-137, 661.660 line, 85.21% * 1.066micro Ci on July 1, 2008, half life 30.0 +/- 0.2 yrs, May 5, 2016 activity = 0.89micro Ci expected rate for 661 line

:= <math>\left (0.8521 \right )\left ( 0.891 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 28059.7 Hz </math>

Mn-54, 1.226 microCi on July 1, 2008, half life =312.20 +/- 0.07 days, 99.975% intensity on 834.826 , May 5, 2016 activity =0.002micro Ci

:= <math>\left (0.99975 \right )\left ( 0.002 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 73.98 Hz </math> for the 834 line

Co-60, 1.082micro Ci July 1, 2008, half life 5.271 +/- 0.001 years, 99.0 % for 1173.237 and 99.9824 % for 1332.501, May 5, 2016 activity=0.39micro Ci

:= <math>\left (0.99 \right )\left ( 0.39 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 14285.7 Hz </math> for the 1173 line

:= <math>\left (0.999824 \right )\left ( 0.39 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 14427.5 Hz </math> for the 1332 line

Below is a table with the calculated efficiencies

{| border="3" cellpadding="5" cellspacing="0"
| Run || Source || Energy (keV) || Expected Rate (Hz) || HpGe Rate (Hz) || HpGe Det D Efficiency (%)
|-
| Eff_C_001 || Na-22 || 511 || 9261.8 || (506:516) (45.65-0.065=45.585) || 0.5
|-
| Eff_C_002 || Cs-137 || 661.657 || 28059.7 ||(657:666)(101.7-0.02281=101.67) || 0.4
|-
| Eff_C_004 || Mn-54 || 834.848 || 73.98 ||(830:839)(0.2704-0.009123=0.2612)||0.4
|-
| Eff_C_003 || Co-60 || 1173 || 14285.7 ||(1164:1182)(34.24-0.01939=34.22)||0.2
|-
| Eff_C_001 || Na-22 || 1274.537 || 5176.7 ||(1270:1279) (11.15-0.0057=11.14)||0.2
|-
| Eff_C_003 || Co-60 || 1332.492 || 14427.5 ||(1328:1337)(28.05-0.05702=27.99)|| 0.2
|}

=Run List=

{| border="3" cellpadding="5" cellspacing="0"
| Date || Time elapsed (Seconds) || Sample || Document Title || Start || Stop || Real || Live || Position
|-
| 04-01-16 || 2.16x10^6 || Se_B || Se_B_002 || 15:55 || 09:15 || 235989.882 || 235687.660 || k
|-
| 04-06-16 || 2.592x10^6 || Se_B || Se_B_003 || 12:57 || Interrupted || computer || crash || k
|-
| 04-14-16 || 3.283x10^6 || Se_B || Se_B_005 || 15:57 || 09:37 || 63581.784 || 63509.895||k
|-
| 04-15-16 || 3.37x10^6 || Sample D || Sample_D_001 || 14:47 || 08:23 || 236172.264 || 236173.271||k
|-
| 04-19-16 || 3.715x10^6 || Sample B || Sample_B_001 ||15:31||15:18 || 85634.862 || 85624.090||k
|-
| 4-20-16 || 3.802x10^6 || Sample C || Sample_C_001 ||15:22||10:19 || 68253.774 || 68232.238||k
|-
| 04-21-16 || 3.888x10^6 || Sample A || Sample_A_001 || 10:22 || 10:37 || 87292.409 || 87268.114||k
|-
|04-25-16 || 4.234x10^6 || Sample E || Sample_E_001 || 11:36 || 10:03 || 80822.406 || 80795.679||k
|-
|04-26-16 || 4.32x10^6 || Se_B || Se_B_008 || 10:06 || 10:29 || 87784.755 || 87664.070 || k
|-
|05-05-16 || 5.098x10^6 || Sample A || Sample_A_002 || 13:31 || 14:30 || 3605.507 || 3602.925 || c
|-
|05-05-16 || 5.098x10^6 || Sample B || Sample_B_002 || 14:34 || 15:26 || 3114.244 || 3112.620 || c
|-
|05-05-16 || 5.098x10^6 || Sample C || Sample_C_002 || 15:28 || 10:57 || 70124.788 || 70044.470 || c
|-
| 05-06-16 ||5.184x10^6|| Sample D || Sample_D_002 || 10:59 || 15:34 || 16516.898 || 16512.570||c
|-
|05-06-16 || 5.184x10^6 || Sample E || Sample_E_004 || 15:37 || 16:18 || 261654.225 || 261344.308 || c
|-
|05-09-16 || 5.443x10^6 || Se B|| Se_B_012 || 16:20 || 11:08||67157.101||66660.298 || c
|-
|05-10-16 || 5.5296x10^6 || Sample A || Sample_A_004 || 11:03 || 15:19 || 15379.475 || 15363.017 || c
|-
|05-10-16 || 5.5296x10^6 || Sample B || Sample_B_004 || 15:22:04 || 11:43 || 73256.181 || 73220.324 || c
|-
|05-16-16 || 6.048x10^6 || Sample C || Sample_C_004 || 16:33 || 08:19 || 56758.980 || 56711.121 || c
|-
|05-18-16 || 6.2208x10^6 || Sample D || Sample_D_006 || 08:44:21 || 14:05 || 19271.829 || 19266.929 || c
|-
|05-18-16 || 6.2208x10^6 || Sample E || Sample_E_006 || 14:08 || 08:06 || 151108.258 || 150955.915 || c
|-
|05-20-16 || 6.3936x10^6 || Se_B || Se_B_014 || 08:08:47 || 08:44 || 261353.204 || 259621.655 || c
|-
|05-23-16 || 6.6528x10^6 || Sample A || Sample_A_006 || 08:48 || 13:49 || 18103.004 || 18091.523 || c
|-
|05-23-16 || 6.6528x10^6 || Sample B || Sample_B_006 || 13:52 || 13:24 || 84763.938 || 84696.083 || c
|-
|05-24-16 || 6.7392x10^6 || Sample C || Sample_C_006 || 13:28:28 || 10:28 || 75571.716 || 75502.871 || c
|-
|05-31-16 || 7.344x10^6 || Sample B || Sample_B_008 || 08:57:22 || 08:55 || 86282.861 || 86237.392 || c
|-
|06-01-16 || 7.4304x10^6 || Sample C || Sample_C_008 || 08:58:39 || 13:31 || 102739.504 || 102647.471 || c
|-
|06-02-16 || 7.5168x10^6 || Sample D || Sample_D_010 || 13:33 || 08:41 || 68915.044 || 68898.246 || c
|}

[[SeRun_01-11-16]]

[[SeRun_03-07-16]]

=References=

<references/>

[[File:Krouse_CanJournChem_40_1962_p367.pdf]]

=MSDS=

[https://www.alfa.com/en/catalog/010603/ Selenium shot, amorphous, 2-6 mm, Puratronic, 99.999% Alfa Aesar product # 10603] [[File:AlphaAesarSelenium_MDSD.pdf]]

=Informative links=

http://www.deq.idaho.gov/regional-offices-issues/pocatello/southeast-idaho-phosphate-mining/southeast-idaho-selenium-investigations/

https://inldigitallibrary.inl.gov/sti/3169894.pdf

http://giscenter.isu.edu/research/Techpg/sisp/index.htm

[[PAA_Research]]

PAA Selenium

2016-09-07T12:19:42Z

Starvale: /* Can one use plant material to measure the provenance of selenium? */

Using PAA ro measure Selenium concentrations.

According to Krouse<ref name="Krous1962"> H.R. Krause and H.G. Thode,"Thermodynamic Properties and Geochemistry of Iosotopic Compounds of Selenium",.Can. J. Chem., vol 40, pg 367</ref>
, the fractional concentration of Se-82/Se-76 in plant material is observed to be less than from primordial (meteoric) concentrations by as much as 1.2%. Anaerobic bacteria are known to reduce selenates and senelites in biological systems. This may be the reason plant material has fractionation of selenium isotopes. They also observe excess concentrations of up to 0.4% in soil.

Plant material appears to detect environmental selenium.

=Can one use plant material to measure the provenance of selenium?=

Natural abundance of selenium

{| border="3" cellpadding="5" cellspacing="0"
| Isotope|| Abundance
|-
| Se-74 || 0.86%
|-
| Se-76 || 9.23%
|-
| Se-77 || 7.60%
|-
| Se-78 || 23.69%
|-
| Se-80 || 49.80%
|-
| Se-82 || 8.82%
|}

=Can one perform PAA measurements of Se-82 and Se-76?=

==Neutron knockout of Se-82==
If you knock a neutron out of Se-82 you produce the unstable isotope Se-81 which Beta emitts with half life of 18 min and a meta-state that emmits a 103 keV gamma with a 57 minute half life.

<math>{82 \atop 34\; }Se (\gamma,n){81 \atop \; }Se</math>

Other prominent photons

260 & 276 keV for the 57 minute half life isotope

==Neutron knockout of Se-76==
If you knock a neutron out of Se-76 you produce the unstable isotope Se-75 which has a half life of 119 days.

<math>{76 \atop\; }Se (\gamma,n){75 \atop \; }Se</math>

The prominent photons emitted have the following energies

136, 264, and 279 keV

The article below describes how plant material and soil contain Se-76 to Se-82 ratios that differ from other natural samples by 1.5%. They argue that it is due to the bacteria living in plant material.

[[File:Krouse_CanJournChem_40_1962_p367.pdf]]

Plant material is a natural way to sample the selenium content to determine if there are difference isotopic ratios due to the impact of human activities on the environment.

=Experiments=

==Chlorine==

It looks like Cl-35 is abundant as you see photon energies of 146 keV and 2127 keV (you can barely see 1176 keV) from Cl-34's decay (neutron knocked out of Cl-35).

The half life is 32 minutes.

Should check the half life from the run AccOnAlInDetASe-AinDetD_001.root using the calibration

MPA->Draw("0.18063+0.960133*evt.Chan>> SeRun_008(8000,0.5,8000.5)","evt.ADCid==3");

== Irradiation of Horse Mineral Supplement==

Below is the EMSL report for the horse feed sample.
https://wiki.iac.isu.edu/index.php/File:EMSL_Report_Horse_Feed.pdf

=== Chlorine is a dominant signal===

First, look at the peak around 146 keV
[[File:146_keV.png | 200 px]]

Next I plotted the counts as a function of time to get an exponentially decaying graph. When doing an exponential fit here, the parameter "b" given by root will be the decay constant.

[[ File:Chlorine.png | 200 px]]

Root gives a half life of 32.9508 +/- 0.01 minutes

Now do the same for the 2127 keV line
[[File:2127_keV.png | 200 px]]

Here are the counts plotted as a function of time
[[File:2127.png | 200 px ]]

Root gives a half life of 35.3962 +/- 0.2 minutes

=== Potassium is a potential signal ===

Looking at the spectrum for the fast irradiation sample, there are 2 prominent lines that could be from 38-K. The mechanism would be a single neutron knockout from a stable 39-K nucleus. The two most dominant energies of the three for 38-K are 2167 keV and 3936 keV and the half life is 7.63 minutes. Below is a fit to the energy spectrum histogram

[[File:2168_peak.png | 200 px]]

Now check the half life

[[File:2167.png | 200 px]]

Root gives a half life of 8.03 +/- 0.02 minutes

Next check the 3936 peak

[[File: 3937_Peak.png | 200 px ]]

and check the half life

[[File: 3936_keV_halflife.png | 200 px ]]

Root gives a value for b = - 1.14372x10^(-3), which in turn gives a half life of 10.1 minutes

It seems very possible that 38-K could be in the sample of horse feed.

== First Observation of Se lines==

Using the 44 Machine at 7 kW power and 44 meV incident electron energy to produce a bremsstrahlung spectrum with a mean energy of 15 meV.

All runs lasting less than 214 seconds have time stamp that gives real time if you divide by clock frequency of 20 MHz. The first 32 bits are used for a real time measurement.

== Detector Efficiency ==

Below is the runlist for finding the efficiency of the detector at position R

{| border="3" cellpadding="5" cellspacing="0"
| Source || Serial # || Reference Date || Activity || Start || Stop || Live
|-
| Na-22 || 129743 || 7-01-08 || 9.427 microCi || 15:49 || 16:19 || 1796.803
|-
| Cs-137 || 129793 || 7-01-08 || 1.006 microCi || 14:25 || 14:56 || 1879.606
|-
| Mn-54 || 129807 || 7-01-08 || 11.77 microCi || 15:00 || 15:30 || 1793.420
|-
| Co-60 || 129740 || 7-01-08 || 10.42 microCi || 15:33 || 15:43 || 569.725
|-
|}

Below are the theoretical calculations for the theoretical decay frequencies

Na-22, 9.427micro Ci on July 1, 2008, half life 2.602 +/- 0.002 years, 99.937% for 1274.52 and 178.8 for 511 line , activity in March 31, 2016 =1.196micro Ci
:= <math>\left (0.99937 \right )\left ( 1.196 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 44,224 Hz </math> for the 1274 line

:= <math>\left (1.788 \right )\left ( 1.196 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 79122.6 Hz </math> for the 511 line

Cs-137, 661.660 line, 85.21% * 1.066micro Ci on July 1, 2008, half life 30.0 +/- 0.2 yrs, March 31, 2016 activity = 0.891micro Ci expected rate for 661 line

:= <math>\left (0.8521 \right )\left ( 0.891 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 28091.2 Hz </math>

Mn-54, 11.77 microCi on July 1, 2008, half life =312.20 +/- 0.07 days, 99.975% intensity on 834.826 , March 31, 2016 activity =0.02328micro Ci

:= <math>\left (0.99975 \right )\left ( 0.02328 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 861.1 Hz </math> for the 834 line

Co-60, 10.42micro Ci July 1, 2008, half life 5.271 +/- 0.001 years, 99.0 % for 1173.237 and 99.9824 % for 1332.501, March 31, 2016 activity=3.759micro Ci

:= <math>\left (0.99 \right )\left ( 3.759 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 137692.17 Hz </math> for the 1173 line

:= <math>\left (0.999824 \right )\left ( 3.759 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 139058.52 Hz </math> for the 1332 line

Below is a table where the actual efficiency will be calculated for position R (farthest position).

{| border="3" cellpadding="5" cellspacing="0"
| Run || Source || Energy (keV) || Expected Rate (Hz) || HpGe Rate (Hz) || HpGe Det D Efficiency (%)
|-
| Eff_003 || Na-22 || 511 || 79122.6 || (506:516) (4.309-0.065=4.244) || 0.005
|-
| Eff_005 || Cs-137 || 661.657 || 28091.2 ||(657:666)(1.105-0.02281=1.0821) ||0.004
|-
| Eff_006 || Mn-54 || 834.848 || 861.1 ||(830:839)(0.04037-0.009123=0.031247)||0.004
|-
| Eff_007 || Co-60 || 1173.228 || 137692 ||(1164:1182)(3.686-0.01939=3.67)||0.003
|-
| Eff_003 || Na-22 || 1274.537 || 44224 ||(1270:1279) (1.073-0.0057=1.0673)||0.002
|-
| Eff_007 || Co-60 || 1332.492 || 139058.52 ||(1328:1337)(3.283-0.05702=3.22598)|| 0.002
|}

Below is a runlist for position k

{| border="3" cellpadding="5" cellspacing="0"
| Source || Serial # || Reference Date || Activity || Start || Stop || Live
|-
| Na-22 || 129743 || 7-01-08 || 9.427 microCi || 14:54 || 15:01 || 434.087
|-
| Cs-137 || 129793 || 7-01-08 || 1.006 microCi || 15:48 || 15:55 || 413.925
|-
| Mn-54 || 129807 || 7-01-08 || 11.77 microCi || 15:28 || 15:40 || 705.186
|-
| Co-60 || 129740 || 7-01-08 || 10.42 microCi || 15:41 || 15:47 || 346.092
|-
|}

Below are the theoretical decay frequencies

Na-22, 9.427micro Ci on July 1, 2008, half life 2.602 +/- 0.002 years, 99.937% for 1274.52 and 178.8 for 511 line , activity in April 14, 2016 =1.183micro Ci
:= <math>\left (0.99937 \right )\left ( 1.183 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 43743.4 Hz </math> for the 1274 line

:= <math>\left (1.788 \right )\left ( 1.183 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 78262.5 Hz </math> for the 511 line

Cs-137, 661.660 line, 85.21% * 1.066micro Ci on July 1, 2008, half life 30.0 +/- 0.2 yrs, April 14, 2016 activity =0.890 micro Ci expected rate for 661 line

:= <math>\left (0.8521 \right )\left ( 0.890 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 28059.7 Hz </math>

Mn-54, 11.77 on July 1, 2008, half life =312.20 +/- 0.07 days, 99.975% intensity on 834.826 , April 14, 2016 activity =0.02251micro Ci

:= <math>\left (0.99975 \right )\left ( 0.02251 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 830.79 Hz </math> for the 834 line

Co-60, 10.42micro Ci July 1, 2008, half life 5.271 +/- 0.001 years, 99.0 % for 1173.237 and 99.9824 % for 1332.501, April 14, 2016 activity=3.74micro Ci

:= <math>\left (0.99 \right )\left ( 3.74 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 136996.2 Hz </math> for the 1173 line

:= <math>\left (0.999824 \right )\left ( 3.74 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 138355.6 Hz </math> for the 1332 line

Below are the actual efficiencies for position k

{| border="3" cellpadding="5" cellspacing="0"
| Run || Source || Energy (keV) || Expected Rate (Hz) || HpGe Rate (Hz) || HpGe Det D Efficiency (%)
|-
| Eff_k_002 || Na-22 || 511 || 79122.6 || (506:516)(49.21-0.6272=48.58) || 0.06
|-
| Eff_k_006 || Cs-137 || 661.657 || 28091.2 ||(657:666)(12.86-0.02281=12.837) ||0.05
|-
| Eff_k_004 || Mn-54 || 834.848 || 861.1 ||(830:839)(0.3204-0.009123=0.311)||0.04
|-
| Eff_k_005 || Co-60 || 1173.228 || 137692 ||(1164:1182)(42.39-0.02053=42.369)||0.03
|-
| Eff_k_002 || Na-22 || 1274.537 || 44224 ||(1270:1279) (12.53-0.005702)=12.52||0.03
|-
| Eff_k_005 || Co-60 || 1332.492 || 139058.52 ||(1328:1337)(35.94-0.005072)|| 0.03
|}

Below is a runlist for position C

{| border="3" cellpadding="5" cellspacing="0"
| Source || Serial # || Reference Date || Activity || Start || Stop || Live
|-
| Na-22 || 129742 || 7-01-08 || 1.146 microCi || 12:55 || 12:57 || 129.782
|-
| Cs-137 || 129793 || 7-01-08 || 1.006 microCi || 13:02 || 13:04 || 123.818
|-
| Mn-54 || 129806 || 7-01-08 || 1.226 microCi || 13:11 || 13:21 || 613.754
|-
| Co-60 || 129739 || 7-01-08 || 1.082 microCi || 13:08 || 13:09 || 103.599
|-
|}

Below are the calculations for the theoretical frequencies

Na-22, 9.427micro Ci on July 1, 2008, half life 2.602 +/- 0.002 years, 99.937% for 1274.52 and 178.8 for 511 line , activity in May 5, 2016 =1.196micro Ci
:= <math>\left (0.99937 \right )\left ( 0.14 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 5176.7 Hz </math> for the 1274 line

:= <math>\left (1.788 \right )\left ( 0.14 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 9261.8 Hz </math> for the 511 line

Cs-137, 661.660 line, 85.21% * 1.066micro Ci on July 1, 2008, half life 30.0 +/- 0.2 yrs, May 5, 2016 activity = 0.89micro Ci expected rate for 661 line

:= <math>\left (0.8521 \right )\left ( 0.891 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 28059.7 Hz </math>

Mn-54, 1.226 microCi on July 1, 2008, half life =312.20 +/- 0.07 days, 99.975% intensity on 834.826 , May 5, 2016 activity =0.002micro Ci

:= <math>\left (0.99975 \right )\left ( 0.002 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 73.98 Hz </math> for the 834 line

Co-60, 1.082micro Ci July 1, 2008, half life 5.271 +/- 0.001 years, 99.0 % for 1173.237 and 99.9824 % for 1332.501, May 5, 2016 activity=0.39micro Ci

:= <math>\left (0.99 \right )\left ( 0.39 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 14285.7 Hz </math> for the 1173 line

:= <math>\left (0.999824 \right )\left ( 0.39 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 14427.5 Hz </math> for the 1332 line

Below is a table with the calculated efficiencies

{| border="3" cellpadding="5" cellspacing="0"
| Run || Source || Energy (keV) || Expected Rate (Hz) || HpGe Rate (Hz) || HpGe Det D Efficiency (%)
|-
| Eff_C_001 || Na-22 || 511 || 9261.8 || (506:516) (45.65-0.065=45.585) || 0.5
|-
| Eff_C_002 || Cs-137 || 661.657 || 28059.7 ||(657:666)(101.7-0.02281=101.67) || 0.4
|-
| Eff_C_004 || Mn-54 || 834.848 || 73.98 ||(830:839)(0.2704-0.009123=0.2612)||0.4
|-
| Eff_C_003 || Co-60 || 1173 || 14285.7 ||(1164:1182)(34.24-0.01939=34.22)||0.2
|-
| Eff_C_001 || Na-22 || 1274.537 || 5176.7 ||(1270:1279) (11.15-0.0057=11.14)||0.2
|-
| Eff_C_003 || Co-60 || 1332.492 || 14427.5 ||(1328:1337)(28.05-0.05702=27.99)|| 0.2
|}

=Run List=

{| border="3" cellpadding="5" cellspacing="0"
| Date || Time elapsed (Seconds) || Sample || Document Title || Start || Stop || Real || Live || Position
|-
| 04-01-16 || 2.16x10^6 || Se_B || Se_B_002 || 15:55 || 09:15 || 235989.882 || 235687.660 || k
|-
| 04-06-16 || 2.592x10^6 || Se_B || Se_B_003 || 12:57 || Interrupted || computer || crash || k
|-
| 04-14-16 || 3.283x10^6 || Se_B || Se_B_005 || 15:57 || 09:37 || 63581.784 || 63509.895||k
|-
| 04-15-16 || 3.37x10^6 || Sample D || Sample_D_001 || 14:47 || 08:23 || 236172.264 || 236173.271||k
|-
| 04-19-16 || 3.715x10^6 || Sample B || Sample_B_001 ||15:31||15:18 || 85634.862 || 85624.090||k
|-
| 4-20-16 || 3.802x10^6 || Sample C || Sample_C_001 ||15:22||10:19 || 68253.774 || 68232.238||k
|-
| 04-21-16 || 3.888x10^6 || Sample A || Sample_A_001 || 10:22 || 10:37 || 87292.409 || 87268.114||k
|-
|04-25-16 || 4.234x10^6 || Sample E || Sample_E_001 || 11:36 || 10:03 || 80822.406 || 80795.679||k
|-
|04-26-16 || 4.32x10^6 || Se_B || Se_B_008 || 10:06 || 10:29 || 87784.755 || 87664.070 || k
|-
|05-05-16 || 5.098x10^6 || Sample A || Sample_A_002 || 13:31 || 14:30 || 3605.507 || 3602.925 || c
|-
|05-05-16 || 5.098x10^6 || Sample B || Sample_B_002 || 14:34 || 15:26 || 3114.244 || 3112.620 || c
|-
|05-05-16 || 5.098x10^6 || Sample C || Sample_C_002 || 15:28 || 10:57 || 70124.788 || 70044.470 || c
|-
| 05-06-16 ||5.184x10^6|| Sample D || Sample_D_002 || 10:59 || 15:34 || 16516.898 || 16512.570||c
|-
|05-06-16 || 5.184x10^6 || Sample E || Sample_E_004 || 15:37 || 16:18 || 261654.225 || 261344.308 || c
|-
|05-09-16 || 5.443x10^6 || Se B|| Se_B_012 || 16:20 || 11:08||67157.101||66660.298 || c
|-
|05-10-16 || 5.5296x10^6 || Sample A || Sample_A_004 || 11:03 || 15:19 || 15379.475 || 15363.017 || c
|-
|05-10-16 || 5.5296x10^6 || Sample B || Sample_B_004 || 15:22:04 || 11:43 || 73256.181 || 73220.324 || c
|-
|05-16-16 || 6.048x10^6 || Sample C || Sample_C_004 || 16:33 || 08:19 || 56758.980 || 56711.121 || c
|-
|05-18-16 || 6.2208x10^6 || Sample D || Sample_D_006 || 08:44:21 || 14:05 || 19271.829 || 19266.929 || c
|-
|05-18-16 || 6.2208x10^6 || Sample E || Sample_E_006 || 14:08 || 08:06 || 151108.258 || 150955.915 || c
|-
|05-20-16 || 6.3936x10^6 || Se_B || Se_B_014 || 08:08:47 || 08:44 || 261353.204 || 259621.655 || c
|-
|05-23-16 || 6.6528x10^6 || Sample A || Sample_A_006 || 08:48 || 13:49 || 18103.004 || 18091.523 || c
|-
|05-23-16 || 6.6528x10^6 || Sample B || Sample_B_006 || 13:52 || 13:24 || 84763.938 || 84696.083 || c
|-
|05-24-16 || 6.7392x10^6 || Sample C || Sample_C_006 || 13:28:28 || 10:28 || 75571.716 || 75502.871 || c
|-
|05-31-16 || 7.344x10^6 || Sample B || Sample_B_008 || 08:57:22 || 08:55 || 86282.861 || 86237.392 || c
|-
|06-01-16 || 7.4304x10^6 || Sample C || Sample_C_008 || 08:58:39 || 13:31 || 102739.504 || 102647.471 || c
|-
|06-02-16 || 7.5168x10^6 || Sample D || Sample_D_010 || 13:33 || 08:41 || 68915.044 || 68898.246 || c
|}

[[SeRun_01-11-16]]

[[SeRun_03-07-16]]

=References=

<references/>

[[File:Krouse_CanJournChem_40_1962_p367.pdf]]

=MSDS=

[https://www.alfa.com/en/catalog/010603/ Selenium shot, amorphous, 2-6 mm, Puratronic, 99.999% Alfa Aesar product # 10603] [[File:AlphaAesarSelenium_MDSD.pdf]]

=Informative links=

http://www.deq.idaho.gov/regional-offices-issues/pocatello/southeast-idaho-phosphate-mining/southeast-idaho-selenium-investigations/

https://inldigitallibrary.inl.gov/sti/3169894.pdf

http://giscenter.isu.edu/research/Techpg/sisp/index.htm

[[PAA_Research]]

G4Beamline PbBi

2015-06-22T16:43:55Z

Starvale: /* Energy Deposition in Target system (Heat) */

Development of a Positron source using a PbBi converter and a Solenoid

=Converter target properties=

Definition of Lead Bismuth

1cm diameter target
2 mm thick PbBi

0.5 Tesla solenoid

Desire to know

Emmittance (mrad * mm)

dispersion (Delta P/P) (mradian/1000th mm/1000th)

of electrons after the PbBi target.

pole face rotation in vertical plane.

=G4BeamLine and MCNPX=

==Target thickness optimization==

===[[PbBi_THickness_GaussBeam]]===
Dmitry's processing of Tony's GEANT simulations showing transverse phase space portrait (left) and longitudinal phase space portrait (right). Phase space portraits show coordinate x or y vs
diveregense=px/pz or py/pz (or time vs kinetic energy ). Captions show:

1. geometric (not normalized) emittance for transverse and emittance for longitudinal phase space portraits (ellipse areas divided by "pi")

2. Twiss parameters

3. Ellipse centroid for longitudinal phase portrait

4. sqrt(beta*emittance) and sqrt(gamma*emittance) - half sizes of the projections of the ellipses on the coordinate and divergence axes respectively.

Electrons - RMS

[[File:Ed1.png| 400 px]]

Electrons - 68.2% core

[[File:Ed2.png| 400 px]]

Positrons - RMS

[[File:Pd1.png| 400 px]]

Positrons - 68.2% core

[[File:Pd2.png| 400 px]]

=== [[PbBi_THickness_CylinderBeam]]===
Dmitry's processing of Tony's GEANT simulations showing transverse phase space portrait (left) and longitudinal phase space portrait (right). Phase space portraits show coordinate x or y vs
diveregense=px/pz or py/pz (or time vs kinetic energy ). Captions show:

1. geometric (not normalized) emittance for transverse and emittance for longitudinal phase space portraits (ellipse areas divided by "pi")

2. Twiss parameters

3. Ellipse centroid for longitudinal phase portrait

4. sqrt(beta*emittance) and sqrt(gamma*emittance) - half sizes of the projections of the ellipses on the coordinate and divergence axes respectively.

Electrons - RMS

[[File:E1.png| 400 px]]

Electrons - 68.2% core

[[File:E2.png| 400 px]]

Positrons - RMS

[[File:P1.png| 400 px]]

Positrons - 68.2% core

[[File:P2.png| 400 px]]

=== [[PbBi_THickness_PntSource]]===

Electrons and Positrons after 2mm of LBE:

Electrons:

[[File:e01.png| 200 px]][[File:e02.png| 200 px]]

Positrons:

[[File:p01.png| 200 px]][[File:p02.png| 200 px]]

===Energy Deposition in Target system (Heat)===

[[File:ElectronTracks.png| 200 px]][[File:PhotonTracks.png| 200 px]]

[[File:ElectronEnergy.png| 200 px]][[File:PhotonEnergy.png| 200 px]]

MCNPX simulations of energy deposition into different cells are below. There is a slight overestimate (they add up to about 120%). Positrons contribute less than 1% of electrons' contribution. No magnetic filed is assumed.

[[File:Model.png| 400 px]]

[[File:Tablen1.png| 200 px]]

[[File:Tablen2.png| 200 px]]

==Solenoid==

Inner Radiusu=

Outer Radius =

Length =

Current=

Magnetic Field Map in cylindrical coordinates (Z & R) from Niowave

=Beam Line Design=

[[PbBi_BeamLine_Elements]]

=goals for JLab=

[[Positrons#Simulations]]

File:P02.png

2015-05-21T21:07:52Z

Starvale:

File:P01.png

2015-05-21T21:05:44Z

Starvale:

File:E02.png

2015-05-21T21:04:26Z

Starvale:

File:E01.png

2015-05-21T21:03:59Z

Starvale:

G4Beamline PbBi

2015-05-21T21:02:49Z

Starvale: /* PbBi_THickness_PntSource */

Development of a Positron source using a PbBi converter and a Solenoid

=Converter target properties=

Definition of Lead Bismuth

1cm diameter target
2 mm thick PbBi

0.5 Tesla solenoid

Desire to know

Emmittance (mrad * mm)

dispersion (Delta P/P) (mradian/1000th mm/1000th)

of electrons after the PbBi target.

pole face rotation in vertical plane.

=G4BeamLine and MCNPX=

==Target thickness optimization==

===[[PbBi_THickness_GaussBeam]]===
Dmitry's processing of Tony's GEANT simulations showing transverse phase space portrait (left) and longitudinal phase space portrait (right). Phase space portraits show coordinate x or y vs
diveregense=px/pz or py/pz (or time vs kinetic energy ). Captions show:

1. geometric (not normalized) emittance for transverse and emittance for longitudinal phase space portraits (ellipse areas divided by "pi")

2. Twiss parameters

3. Ellipse centroid for longitudinal phase portrait

4. sqrt(beta*emittance) and sqrt(gamma*emittance) - half sizes of the projections of the ellipses on the coordinate and divergence axes respectively.

Electrons - RMS

[[File:Ed1.png| 400 px]]

Electrons - 68.2% core

[[File:Ed2.png| 400 px]]

Positrons - RMS

[[File:Pd1.png| 400 px]]

Positrons - 68.2% core

[[File:Pd2.png| 400 px]]

=== [[PbBi_THickness_CylinderBeam]]===
Dmitry's processing of Tony's GEANT simulations showing transverse phase space portrait (left) and longitudinal phase space portrait (right). Phase space portraits show coordinate x or y vs
diveregense=px/pz or py/pz (or time vs kinetic energy ). Captions show:

1. geometric (not normalized) emittance for transverse and emittance for longitudinal phase space portraits (ellipse areas divided by "pi")

2. Twiss parameters

3. Ellipse centroid for longitudinal phase portrait

4. sqrt(beta*emittance) and sqrt(gamma*emittance) - half sizes of the projections of the ellipses on the coordinate and divergence axes respectively.

Electrons - RMS

[[File:E1.png| 400 px]]

Electrons - 68.2% core

[[File:E2.png| 400 px]]

Positrons - RMS

[[File:P1.png| 400 px]]

Positrons - 68.2% core

[[File:P2.png| 400 px]]

=== [[PbBi_THickness_PntSource]]===

Electrons and Positrons after 2mm of LBE:

Electrons:

[[File:e01.png| 200 px]][[File:e02.png| 200 px]]

Positrons:

[[File:p01.png| 200 px]][[File:p02.png| 200 px]]

===Energy Deposition in Target system (Heat)===

[[File:Layout.png| 400 px]]

[[File:ElectronTracks.png| 200 px]][[File:PhotonTracks.png| 200 px]]

[[File:ElectronEnergy.png| 200 px]][[File:PhotonEnergy.png| 200 px]]

MCNPX simulations of energy deposition into different cells are below. There is a slight overestimate (they add up to about 120%). Positrons contribute less than 1% of electrons' contribution. No magnetic filed is assumed.

[[File:Model.png| 400 px]]

[[File:Tablen1.png| 200 px]]

[[File:Tablen2.png| 200 px]]

==Solenoid==

Inner Radiusu=

Outer Radius =

Length =

Current=

Magnetic Field Map in cylindrical coordinates (Z & R) from Niowave

=Beam Line Design=

[[PbBi_BeamLine_Elements]]

=goals for JLab=

[[Positrons#Simulations]]

G4Beamline PbBi

2015-05-21T21:02:16Z

Starvale: /* PbBi_THickness_PntSource */

Development of a Positron source using a PbBi converter and a Solenoid

=Converter target properties=

Definition of Lead Bismuth

1cm diameter target
2 mm thick PbBi

0.5 Tesla solenoid

Desire to know

Emmittance (mrad * mm)

dispersion (Delta P/P) (mradian/1000th mm/1000th)

of electrons after the PbBi target.

pole face rotation in vertical plane.

=G4BeamLine and MCNPX=

==Target thickness optimization==

===[[PbBi_THickness_GaussBeam]]===
Dmitry's processing of Tony's GEANT simulations showing transverse phase space portrait (left) and longitudinal phase space portrait (right). Phase space portraits show coordinate x or y vs
diveregense=px/pz or py/pz (or time vs kinetic energy ). Captions show:

1. geometric (not normalized) emittance for transverse and emittance for longitudinal phase space portraits (ellipse areas divided by "pi")

2. Twiss parameters

3. Ellipse centroid for longitudinal phase portrait

4. sqrt(beta*emittance) and sqrt(gamma*emittance) - half sizes of the projections of the ellipses on the coordinate and divergence axes respectively.

Electrons - RMS

[[File:Ed1.png| 400 px]]

Electrons - 68.2% core

[[File:Ed2.png| 400 px]]

Positrons - RMS

[[File:Pd1.png| 400 px]]

Positrons - 68.2% core

[[File:Pd2.png| 400 px]]

=== [[PbBi_THickness_CylinderBeam]]===
Dmitry's processing of Tony's GEANT simulations showing transverse phase space portrait (left) and longitudinal phase space portrait (right). Phase space portraits show coordinate x or y vs
diveregense=px/pz or py/pz (or time vs kinetic energy ). Captions show:

1. geometric (not normalized) emittance for transverse and emittance for longitudinal phase space portraits (ellipse areas divided by "pi")

2. Twiss parameters

3. Ellipse centroid for longitudinal phase portrait

4. sqrt(beta*emittance) and sqrt(gamma*emittance) - half sizes of the projections of the ellipses on the coordinate and divergence axes respectively.

Electrons - RMS

[[File:E1.png| 400 px]]

Electrons - 68.2% core

[[File:E2.png| 400 px]]

Positrons - RMS

[[File:P1.png| 400 px]]

Positrons - 68.2% core

[[File:P2.png| 400 px]]

=== [[PbBi_THickness_PntSource]]===

Electrons and Positrons after 2mm of LBE:

Electrons:

[[File:e1.png| 200 px]][[File:e2.png| 200 px]]

Positrons:

[[File:p1.png| 200 px]][[File:p2.png| 200 px]]

===Energy Deposition in Target system (Heat)===

[[File:Layout.png| 400 px]]

[[File:ElectronTracks.png| 200 px]][[File:PhotonTracks.png| 200 px]]

[[File:ElectronEnergy.png| 200 px]][[File:PhotonEnergy.png| 200 px]]

MCNPX simulations of energy deposition into different cells are below. There is a slight overestimate (they add up to about 120%). Positrons contribute less than 1% of electrons' contribution. No magnetic filed is assumed.

[[File:Model.png| 400 px]]

[[File:Tablen1.png| 200 px]]

[[File:Tablen2.png| 200 px]]

==Solenoid==

Inner Radiusu=

Outer Radius =

Length =

Current=

Magnetic Field Map in cylindrical coordinates (Z & R) from Niowave

=Beam Line Design=

[[PbBi_BeamLine_Elements]]

=goals for JLab=

[[Positrons#Simulations]]