Neutron TGEM Detector Abdel

2009

2010

AFCRD Reports-2011

• A vendor is being sought for a flex circuit version of the readout card adapter in order to allow the readout cards to attach to the detector more easily.
• A detector gas system upgrade is underway and should be completed before the next quarter
• A new TGEM card has been machined which was redesigned to reduce spark discharge between two adjacent TGEM preamplifier cards previously observed at 1.7 kV. The expectation is to reach a TGEM voltage of 2 kV with two preamplifier cards stacked on top of each other and separated by 2.5 mm.

January

• Determined the closest distance between two TGEM amplifier cards at 2kV to be 2.5 cm.
• Readout card adapters have arrived
• A third TGEM amplifier has been fabricated

February

• A third THGEM card is installed, the detector is ready to test with cosmic rays.
• New flex circuit adapter cards have been stuffed with connectors. The 16 signals on five 20 pin connectors will be merged onto one 130 connector used by the digitization cards.
• New HV-circuit design is ready to give the needed voltage to operate three THGEM cards simultaneously with the cathode.
• A gas system is currently in place with a 50 micron filter and a flow meter. Check valves are being sought to support a system using 2 supply tanks for continuous operation. The check valves will allow an empty tank to be replaced while the gas system continues operating on a second tank.

Look for NE213 and NE230 liquid scintillator detectors for fast neutrons. Does the neutron leave the detector?

March

• The detector's cathode-TGEM distance had to be increased in order to avoid a spark discharge problem was found when testing the detector at HV using cosmic rays.
• A modification took place on the detector's cavity by raising up the detector's widow 5 cm which helped to increase the distance between the cards.

April

• A setback to the project occurred when a spark discharge event, during excessive testing, destroyed our 3 THGEM pre-amplifiers.
• Seven FR4 cards, coated with resistive paste, were submitted to the machine shop in ISU and they will be ready in the time after May 15.

May

• Two new THGEM cards and cathode have been installed in the THGEM detector. the card testing is going according to the procedure mentioned below.[[1]]

1/13/11

Sparking Test

Sparking test for the HT-THGEM of holes size(76) and rim (63)

Separation distance (mm)	type of gas surrounding	V1GB (kV)	V1GT(kV)	V2GB (kV)	V2GT (kV)	Notes
6.5	Ar/CO2	0
5.0	Ar/CO2	0
2.6	Ar/CO2	0	-2	+2	-3	sparking on the edge then holes starts to spark too
2.6	Air/CO2	0	-2	-2	0	no sparking.

where:

V1GB = bottom of the first THGEM card which is placed 2 mm above the charge collector

V1GT = top of the first THGEM card

V2GB = bottom of second THGEM card just above the first TGEM card.

V2GT = top of second THGEM card.

1/21/11

• The THGEM card is still sparking because of the hook up wires; which are tested up to 600V by the manufacturer.

The maximum voltage applied for one card only is 2000V on the top and 2000V on the bottom of the card. As soon as the voltage increases more than 2000V on the bottom of the card. a spark is seen in the hole that contains the hook up wire. There is an insulation problem may get serious specially if we still planning to apply 4kV and 6kV on the THGEM card.

The following website is offering hook up wires solid core and can hold up to 2000V, 24 gauge size.

http://caledonian-cables.com/product/Hoop-Up_Wire/UL_1430_Hoop-Up_Wire.htm

we may use the wires supported by the glu to have a good insulation.

• Next step is to repeat the experiment again but after adding the glu on the soldered parts.

2/14/11

Leakage current test

On Thur. 2/10 the leakage current measured for the max. voltage (around 300V) was in 25 nA using user1 setup.

Today the measured current for the voltages shown in the table using user0 setup in clean environment:

Source Voltage(V)	GEM Voltage (V)	Current (uA)	Notes
500	196	6.1	Sparking rate was high in the beginning, higher current observed in a higher sparking rate
570	224	23	GEM sparking rate decreased after a while, current most of the time in the range of the noise level

Switching to user1 setup when the voltage applied 224V on GEM foil, the maximum current measured was around 10um. The result is not enough to compare the accuracy of the two setups, but it gives a feeling that user1 setup is underestimating.

• The 3rd THGEM card is ready to pick up, the vendor suggested to find another place to do the one with massive number of holes since this semester there is not any time available to do it.

I will start working to collect the 3 cards together using the high voltage circuit distribution, an adjust is going to take place to get the desired voltage for the 3 cards in addition to the cathode.

2/15/11

The following figure shows the elastic xsection and fission xsection for U-238:

The elastic scattering is higher over the energy range of 5-14 MeV, the probability for the U-238 to recoil is higher than that to have a fission.

2/17/11

• The high voltage circuit is ready to get a voltage up to 9 kV from the source to provide a voltage up to 2 kV for each THGEM card and potential difference between successive cards up to 115 V (between the high voltage sides) and 80 V (between successive low voltage sides).

2/22/11

Circuit 1

The operating voltage for the HV-circuit is 5kV, the voltages on the sides of the THGEM cards is as the following:

Source Voltage(kV)	THGEM_T1 (kV)	THGEM_B1 (kV)Current (uA)	THGEM_T2 (kV)Notes	THGEM_B2 (kV)	THGEM_T3 (kV)	THGEM_B3 (kV)
5.15	5.15	2.92	5.00	2.88	2.49	1.90

But in the case of connecting the two circuits together, the effect of the capacitor extends to the other circuit causing the difference in voltage between top and bottom of each THGEM cards is only 0.5kV.

3/10/11

New design for HV-circuit

A new design is ready to feed the THGEM cards with voltage difference up to 2kV between the top and the bottom side of the card. Also source drops gradually according to that difference from 6 kV (operating voltage) to 0.1 on the bottom of the card which is closer to the read out card.

The follwing table shows the voltage distribution to the cards as the voltage source rises from 4 kV up to 6.5 kV.

Voltage source (kV)+_ 0.01	THEGM card number	Top side voltage(kV)+_ 0.01	Bottom side voltage (kV)+_ 0.01	Voltage difference between the two sides (kV)+_ 0.01
4.06	1	4.06	2.85	1.21
	2	2.36	1.44	0.92
	3	1.38	0.08	1.3
4.50	1	4.50	3.15	1.35
	2	2.71	1.58	1.13
	3	1.54	0.08	1.46
5.00	1	5.00	3.55	1.45
	2	3.06	1.86	1.2
	3	1.80	0.11	1.69
5.50	1	5.50	3.81	1.69
	2	3.74	2.04	1.78
	3	1.98	0.12	1.86
6.02	1	6.02	4.13	1.89
	2	3.92	2.20	1.72
	3	2.15	0.13	2.02
6.52	1	6.52	4.47	2.05
	2	4.28	2.39	2.11
	3	2.33	0.14	2.15

THGEM card number 1 is the closest to the cathode. THGEM card number 3 is the closest to the readout card.

• When the voltage is 6 kV, the current that passes through the circuit is [math] I = 6000/42 Mohm = 142 uA [/math]

3/18/11

Sparking Cathode

The cathode is still sparking even when it is replaced by another new one with the same dimension and distance from the THGEM cards. when I tried to make a little higher I could not since the top part of the detector has less space to get the increment in height.

Machining the top part is important to get more distance for the cathode to avoid the sparking (minimum another 2 cm and if it is more it would be better).

if we succeed to get that space, then a longer corner screw can be installed to give us a little flexibility to get a better distance for the cathode as it is mounted vertically.

4/4/11

• The detector window's extension is completed and it is test, totally sealed without any gas leakage.

4/9/11

• The THGEM is tested to look for a signal, Na-22 and Co-60 sources were used for this purpose, the result that New kind of peaks were detected followed by a tail. Unfortunately the test did not reach the full voltage capacity (up to 6.5 kV) but it was operating under 4.5 kV.

• The detector was tested again before removing the cards without Ar/CO2 gas, the applied voltage on the cards was up to 2.5-2.7 kV, without any sparking, cathode was under 8 kV, without any sparks, I excluded the distance between the cards is small to cause a spark, otherwise I won't be able to reach that high voltage without any sparks.

• The detector was inspected after the test, signs of sparking were very clear on the THGEM, and they all located in the same side for the 3 cards but in different degrees of burns (the bottom one was he worst). Through the inspection I was wondering how can they all be burnt on the same side of the card ?????

4/13/11

• The detector was tested without the cathode, the maximum voltage was 6 kV without sparking, looks the distance should be increased to exclude it of being a reason for sparking and to hit 6.5 kV easily.

• The distance is increased to about 1 mm, the detector is tested again and we hit 6.3 kV as maximum voltage on the THGEM without the cathode.

4/14/11

• The distance between the THGEM is increased to another 1mm ( to have a total of 0.5 cm), the cathode is added to the group with a maximum distance from the top THGEM card, observation will uploaded as soon as possible.

4/18/11(HV-probe)

The following is a list of what is available in the markets:

http://shop.ebay.com/i.html?rt=nc&LH_BIN=1&_nkw=probe+high+voltage&_dmd=1&_sop=12&_trksid=p3286.c0.m301

This is what the IAC are using :

http://cgi.ebay.com/FLUKE-80K-40-AC-DC-HIGH-VOLTAGE-PROBE-/190503643488?pt=LH_DefaultDomain_0&hash=item2c5ae6e960

I think this is good for our our application , (the price with shipping = 119 + 7 +_ 1) :

http://www.mouser.com/ProductDetail/BK-Precision/HV-44A/?qs=sGAEpiMZZMtNaRJxj63fb%2F49ig1SXyqg1%2FPoyVZEbeA%3D

5/26/11

There are new 6 THGEM cards machined and ready for installation.

• Steps of Installing the new THGEM cards

1- Cleaning the chamber under the laminar hood.

2- Cleaning the card very well by alcohol and be sure there is not any place on the surface that may collect charge.

3- Installing a card then performing the discharge test up to 2 kV.

4- whenever the card passes the discharge test another card will be added until 3 cards installed in the chamber.

5- Adding the cathode to an appropriate distance in a way the charged particle range is covered within this distance and there is not any discharge.

• Procedure for adding an alpha source film to the detector to test the detector signal???? Please add your comments.

• GEANT4 changes:

A discussion about the ENDF data used by GEANT4 9.4 that does not include Th-232 fission cross section, the collaborators recommended me to contact Tatsumi for more information about the Th-232 and U-238 cross sections . He sent me a files that I can install in GEANT4 ENDF directory, I ma going ot repeat the simulation again for U-238 target of thickness of 1 um to measure the to calculate the fission cross section. They also recommend me to contact the INCL model programmer and discuss with him the issue of underestimating the values of the fission cross section in our simulation.

I am going to start my simulation on BREMS using the new fission cross section file. Is that ok?

6/14/11

Three different cathodes were tested in a distance of 10.5 mm from the last THGEM and I still have a sparking problem.

Installing two THGEM cards with a separation distance of 3 mm does not cause any problem without the cathode.

I am trying to find a way to have a cathode that can hold up a high voltage without sparking. (the only idea I have is use one of the FR4 double clad sheet as a cathode after I etch one side completely, please add your feedback Dr. Forest).

6/21/11

Three THGEM cards has been installed in the gas chamber without a cathode. they have equal vertical separation distances of 3 mm from each other and from the readout plate. A voltage up to 6 kV was applied without any sparking, but unfortunately the the power supply was tripped without observing any sparks on the oscilloscope. I am going to open the detector tomorrow and be sure there is any signs of discharge, then repeat the test again as hope to reach to 6.5 kV.

6/22/11

• The installed THGEM cards were tested, they are not any signs of discharge on any card when the voltage is up to 6 kV.

• The HV for the THGEM cards tripped when 6.5 kV was reached. The distance between THGEM cards was 7.5 mm and the current through the HV resistor network reached 150 [math]\mu[/math]A current.

• A step should be taken to build a union to add the cathode.

6/23/11

• Three THGEM cards were tested under a voltage of 6 kV supported by 140 uA, the detector is stable without any increase in the background noise or passage through any discharge, the detector was on from 5:45-6:45am.

• As the voltage increases to 6.2 kV with 145 uA, a discharge tripped the voltage after about 5 minutes. time between 7:00 and 7:05 am

• The experiment is repeated again to 6.2kV but using only 143 uA. the voltage tripped after 7 minutes (7:23-7:30am) which indicates the exitance of discharge at this voltage. but the experiment is going to be repeated again through the day.

• When the voltage is 5.5 kV and current is 127 uA, noise we detected up to 632 mV.

6/24/11

• An overnight tested has been done for 3 THGEM cards installed in the gas chamber, the voltage applied is 5.5 kV and the current is 128 uA. The HV did not trip when operating the detector at 5.5 kV over the time period from 6/23/11 at 6:15 pm until 6/24/11 6:00am. The scope threshold was set to 400 mV and single mode. A scope trace was not observed overnight indicating that a voltage excursion beyond 450 mV did not occur. A noise level was measured using the scope between 6 and 6:30 am on 6/24/11. The average noise voltage was between 300-350mV (peak to peak).

6/25/11

• The test for the 3 THGEM cards was repeated between 7:30- 8:10pm under a voltage of 6.3kV and a current of 148 [math]\mu A[/math]. The detector was tripped by a discharge shown below.(power supply trip circuit has a T-shape connector divides the signal between the discriminator with a voltage of 0.4V and the oscilloscope)

6/27/11

• The test for the 3 THGEM cards was repeated at 11:10am under a voltage of 6.2kV and a current of 144 [math]\mu A[/math]. The power supply is tripped at 11:40am by discharge.

• The test for the 3 THGEM cards was repeated at 2:10pm under a voltage of 6.2kV and a current of 144 [math]\mu A[/math]. The power supply is tripped at 2:32pm by a discharge which appears clearly after decreasing the time scale to 20ns as shown above.

6/28/11

• The test for the 3 THGEM cards was repeated at 5pm under a voltage of 5.5kV and a current of 125 [math]\mu A[/math]. There is not any discharge in the detector until 6:27pm.
• The voltage was increased to 6 kV and a current of 140 [math]\mu A[/math], the Power supply tripped but an image was not captured on the oscilloscope.

6/29/11

• The test was repeated at 6:38pm (6/28/11) under a voltage of 5.5kV and a current of 125 [math]\mu A[/math]. There is not any discharge or noise that may cause the power supply to trip until 5:30am (6/29/11).

• At 3:30pm under a voltage is increased up to 6kV and a current of 140 [math]\mu A[/math].The power supply is tripped in 15 minutes.

• The test was repeated at 4:30pm under a voltage of 5.5kV and a current of 140 [math]\mu A[/math].A discharge of about 2V (peak to peak) is detected (observed by 8:15pm) and it did not trip the power supply. The current is decreased the 130 [math]\mu A[/math].

6/30/11

• The previous test is still running until 5:30 am without showing any discharge after the current is decreased to 130[math]\mu A[/math], the voltage was decreased gradually without increasing the current unless it is needed, the voltage increment is 100 V every 15 minutes. The applied voltage is 6kV and 138[math]\mu A[/math] at 6:40am, the detector is tripped by a discharge at 7:20am.

Summary or testing 3 THGEM cards with a distance of 7.5 mm without a cathode

Table of observations

Date and time	Test Duration	Voltage source [math](kV) \pm 0.01 [/math]	Current [math](\mu A) \pm 1 [/math]	Notes
6/22/11	N/A	6.5	150	the power supply tripped directly
6/23/11 5:45-6:45am	1hr	6	137	increment 20V until 5.5V then 5V until 6 kV
6/23/11 7-7:05am	5min	6.2	145	increment 20V until 5.5V then 5V until 6.2 kV
6/23/11 7:23-7:30am	7min	6.2	143	increment 20V until 5.5V then 5V until 6.2 kV but the current provided when it is needed
6/25/11 7:30-8:10pm	50min	6.3	145	increment 20V until 5.5V then 5V until 6.3 kV (T-shape connector divides the signal between the discriminator with a voltage of 0.4V and the oscilloscope)
6/27/11 11-11:40am	30min	6.2	144	increment 20V until 5.5V then 5V until 6.2 kV (weekend)
6/27/11 2-2:32pm	32min	6.2	144	increment 20V until 5.5V then 5V until 6.2 kV
6/28/11 5pm-3:30pm	22.5hr	5.5	125	increment 20V and there is not any discharge
6/28/11 3:30-3:45pm	15min	6	137	over night at 5.5kV then 5V until 6 kV
6/29/11 3:30-3:45pm	15min	6	137	over night at 5.5kV then 5V until 6 kV
6/29/11 4:30pm-5:30am	13hr	5.5	125	increment by 5V, a discharge is observed but it was not enough to trip
6/30/11 6:40pm-7:20am	40min	6	137	increment by 5V and 15 min waiting time every 100V , proving the current when it is needed
7/1/11 9:15pm- 8:10am(or earlier)	9	5.5	124	increment by 5V, a discharge is observed by the time mentioned

7/5/11

• The vertical distance between the THGEM card is 9 mm except for top one that follows the union, it has a distance of 11mm.

Date and time	Test Duration	Voltage source [math](kV) \pm 0.01 [/math]	Current [math](\mu A) \pm 1 [/math]	Notes
7/5/11_2:53-2:58pm	5 min	6.1	140	The voltage is gradually increased and sets for 45 min. as it is 6kV
7/5/11_7:25pm-11pm	4.55 h	5.5	125	No discharge
7/5/11_11pm-5am	6h	5.75	130	Discharge with small peaks
7/6/11_5:50am		5.75	130		50px

• HV_circuit IV table:

Voltage source [math](kV) \pm 0.01 [/math]	Current [math](\mu A) \pm 1 [/math]
5.5	125
5.75	130
6	137
6.1	140

Comparison ENDF evaluation of U-238 neutron fission xsection and GEANT4

INTERNATIONAL EVALUATION OF NEUTRON CROSS-SECTION STANDARDS, INTERNATIONAL ATOMIC ENERGY AGENCY,VIENNA, 2007 File:U238-xsection.pdf

absolute f_xsection in the table 7.1 p.91

Ref. number	inxn	data description	author	citation	notes
809	238U(n,f)	Absolute	G. Winkler et al.	91Jülich (1991) 514	the paper represents f_xsection ratio measurements of U_238 to Al_27, Na_24, Fe_56, Mn_56 * found in library QC770 N742 1992)
810	238U(n,f)	Absolute	K. Merla et al.	91Jülich (1991) 510	* The paper represents f_xsection ratio measurements of U_238, U_235 , Np_237, and Pu_239 for 4.45 MeV, 8.46 MeV, 18.8 MeV * very accurate description for the experiment details and through the figures and the tables * found in library QC770 N742 1992)
877	238U(n,f)	Absolute	I.M. Kuks et al.	At. Energy 30 (1971) 55	*measured f_xsection U_238 fission for 2.5 MeV Neutrons
860	238U(n,f)	Absolute	N.N. Flerov et al.	At. Energy 5 (1958) 657	*title : antinutrino , Mean number of neutrons emitted in fission of U235 and U238 by 14-Mev neutrons, Mean number of neutrons emitted in fission of U235 and U238 by 14-Mev neutrons

Done In April (edited by 04/30/10)

1.)Testing the new laminate with random holes after applying the resistive paste on both sides. Also, the trial of applying the paste was done, 0.1 inch brush is used for that to avoid covering the holes with the paste. the following procedure were taken:

a- Voltage is applied on the the foil to check the first sparking place.

b- Applying the paste carefully on the area between the holes with very small quantities.

Result

a) Applying the paste shifts the sparking area to next neighboring one, so looks this will lead us to cover all the areas between the holes to kill the sparks.

b)A need to keep the foil under voltage to keep tracking of the sparks which lead unfortunately led to loss the voltage between the two copper layers.

Even a drop of paste got stuck in one of the holes(which has low possibility since I cleaned all the paste applied very well), or the two layers are no longer isolated from each other!

2.)Final touches on the HV-circuit are done, diagrams are done by eagle with Gerber files, the chamber is ready for redesigning.

3.)Running Th-232 fission simulation without ionization on inca and daq1. Energies 1-9MeV (inca) and 19-22 MeV(daq1) will be done by today(04/30/10).

4.)Tracking the process to get Th-232, contacting other vendors for radioactive isotopes, trying to get low cost ones.

Th-232 and U-238 Activity in mCi

General information:

Physical properties	U-238	Th-232
Half life in years	4.468 X 10^9	1.405 X 10^10
Decay rate per second	4.91 X 10^-18	1.56 X 10^ -18
Molar Mass g/mol	238.02891	232.0381
Activity of 2 kg in mCi	0.68	0.22

Avogadro's number is 6.0221 X 10^23 /mol

1 Ci = 3.7 X 10^10 disintegration/ second

[math]2 \times 10^3 g \times \frac{1 mol}{238.03 g} \times \frac{6 \times 10^{23} atoms}{mol} \times \frac{decay}{4.4 \times 10^{9} years} \times \frac{yr}{365\times 24 \times 3600 sec} \frac{1 Ci}{3.7 \times 10^{10} decays/sec} \equiv 0.98 mCi[/math]

[math] \ Half Life \times \ Decay Rate = ln2 [/math]

[math]2 \times 10^3 g \times \frac{1 mol}{238.03 g} \times \frac{6 \times 10^{23} atoms}{mol} \times \frac{ ln2\times \ decay}{4.4 \times 10^{9} years} \times \frac{yr}{365\times 24 \times 3600 sec} \frac{1 Ci}{3.7 \times 10^{10} decays/sec} \equiv 0.68 mCi[/math]

References

2010 THGEM design(s)

File:THGEM 2009 design gas efficiency.pdf

Simulations_of_Particle_Interactions_with_Matter

Voss and 3 russian references for Dy(n,x) cross sections

Media:Shalem_MSthesis_march2005.pdf

http://arxiv.org/abs/0903.3819 Dy photon gammas spectrum

http://www.ippe.obninsk.ru/podr/cjd/kobra13.php?SubentID=30974002

http://www.americanelements.com/thoxst.html

http://arxiv.org/pdf/physics/0404119

NIM_A535_2004_93[2]

File:NIM A590 2008 pg134 Eberhardt.pdf Prep Targets

Neutron cross sections for different elements Media:Neutron_cross_sections.pdf

http://www-nds.iaea.org/RIPL-2/

Media:n gamma cross sections at 25 keV.jpg

Media:n alpha cross section at 14.2 MeV.jpg

Media:ne cross section at 14 MeV.jpg

Media:high enegy fission x-section.jpg

Media:N_gamma_x-section_at_400_keV.jpg

Media:x-sections of reactions at 14 MeV.jpg

Media:n p x-section at 14.3MeV.jpg

Media: n gamma x-section at 14.5 MeV.jpg

Media: elastic x-section at 0.5 MeV.jpg

Media: n gamma x-section at 1 MeV.jpg

Media: n 2n x-section at 14.3 MeV.jpg

Donald James Hughes, Neutron cross sections, 2nd edition 1958, u.s.a atomic energy commission.Media:Neutron cross sections.pdf

File:NSAE 151 2005 319-334 Y.D. Lee.pdf

TGEM-2009 File:TGEM 2009.pdf

12 Volt power supply system.

http://www.lnf.infn.it/esperimenti/imagem/doc/NIMA_46128.pdf

http://electrontube.com.Media: rp097mono HV divier.pdf

http://www.cerac.com/pubs/proddata/thf4.htm#anchor550078

http://en.wikipedia.org/wiki/PC_board

http://wikipedia.org

A : concise review on THGEM detectors A.Breskin, R. Alon, M. Cortesi, R. Chechik, J. Miyamoto, V. Dangendorf, J. Maia, J. M. F. Dos Santos

GEANT4_Paticles_Models[3]

Resistors online store : http://www.justradios.com/rescart.html

RETGEMs

Media:Jinst8_02_p02012_THGEM_spark.pdf‎

Media:2010_INST_5_P03002.pdf‎

Thick GEM COBRA

Media:THGEM_COBRA_08_10.pdf‎

Media: Nucl_Phys_B_Bidault_ novel UV photon detector.pdf

Media:Mauro micro pattern gaseuos detectors.pdf

Media:Development and First Tests of GEM-Like Detectors With Resistive Electrodes.pdf

http://www.supplydivision.co.uk/genitem.htm

http://www.radioshack.com/search/index.jsp?kwCatId=&kw=24%20gauge%20wires&origkw=24%20gauge%20wires&sr=1

Thick_GEM_versus_thin_GEM_in_two_phase_argon_avalanche_detectors (HV circuit)[4]

Stainless Steel deflection [5]

Th-Xsection references

File:Th-232 fxsection Behrens 0.7-1.4MeV.pdf

File:Th-232 fxsection Blons 1975 1.2-1.8MeV.pdf

File:Th-232 fxsection ermagambetov 0-3MeV.pdf

File:Th-232 fxsection Henkel 0-9MeV.pdf

File:Th-232 fxsection Ohsawa original.pdf

File:Th-232 fxsection pankratov 3-35MeV.pdf

File:Th-232 fxsection protopopov distancefromthesource.pdf

File:Th-232 fxsection rago 12.5-18MeV.pdf

U-238-Xsection and coating references

relative cross section and calibration samples characteristics for a well determined number of fissions per second

File:Eismont relative absolute nf induced intermediate energy.pdf

U_238 cross section error analysis

INTERNATIONAL EVALUATION OF NEUTRON CROSS-SECTION STANDARDS, INTERNATIONAL ATOMIC ENERGY AGENCY,VIENNA, 2007 File:U238-xsection.pdf

U_238 (0.5-4MeV) and Th_232 (1-6MeV) fission cross section with statistical error.File:Th-232 U238 xsetion data ebars.txt

File:Pankratov fxsection Th232 U233 U235 Np237 U238 5-37MeV.pdf

Thorium Coating

ThF4 target for sputtering coatings

http://www.cerac.com/pubs/proddata/thf4.htm

Machining Uranium

Uranium will ignite in powder form

http://www.springerlink.com/content/rr072r52163x0833/

coating Uranium

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TVV-46G57SW-53&_user=10&_coverDate=10%2F01%2F1991&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1388383717&_rerunOrigin=google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=c3229e061695dfa28617f9f5db1ef55d

http://cat.inist.fr/?aModele=afficheN&cpsidt=16864172

Calorimeters/Detectors: DU sheet is in wide-scale use as an absorber material in high-energy physics research at large accelerator laboratories. The high atomic number and density of DU presents a large number of atoms per unit volume to interact with the particles emerging from collisions in these detectors. Also the slight background radiation from DU enables in situ calibration of the electronic read out devices within such detectors, thereby improving the accuracy of measurement.

http://www.2spi.com/catalog/chem/depleted-uranium-products.html

http://books.google.com/books?id=NRXnXmFRjWYC&pg=SA48-PA17&lpg=SA48-PA17&dq=depleted+uranium+coating&source=bl&ots=a6jHsdI6Ec&sig=zVxKGeD4E42gAVkr8Otg9bfpkyg&hl=en&ei=8FgtTIH1HMGC8gbNl-S-Aw&sa=X&oi=book_result&ct=result&resnum=6&ved=0CCoQ6AEwBThG

http://www.google.com/url?sa=t&source=web&cd=90&ved=0CDYQFjAJOFA&url=http%3A%2F%2Fwww.ga.com%2Fenergy%2Ffiles%2FIFT_Catalog.pdf&ei=RFktTPbgKYL88AbC1tSSAw&usg=AFQjCNE3VbqBWbvcKln4pJVAj8FyKfcOig

IAEA Photonuclear Data Library [6]

Data Acquisition

Warren_logbook[7]

Warren_Thesis [8]

Related To Gaseous Detectors

Breakdown and Detector Failure (10/21/10)

Different kind of micro-pattern detectors

References

1- A. Bressan, M. Hocha : NIM A 424 (1999) 321—342 File:High rate behavior and discharge limits in micro-pattern detectors .pdf

2- Fonte and Peskov IEEE 1999 :File:Fundamental limitations of high rate gaseous detectors.pdf

3- B. Schmidt: NIM A 419 (1998) 230—238 File:Microstrip gas chambers Recent developments radiation damage.pdf

Ideas

1.) Can we mix resistive paste (Encre MINICO) with TH-232. We construct a "bed of nails" to place a predrilled G-10 board with a copper border. The nails fill in the holes of the G-10 to keep the paste out. Ecre MINICO is a resistive paste used for transistors.

a.) Get some resistive paste.

http://www.leggesystems.com/p-253-elimstat-uxm-ccp.aspx

Resistive glue to compare

File:Duralco 4461.pdf

http://www.ellsworth.com/conformal.html?tab=Products

http://www.ellsworth.com/display/productdetail.html?productid=764&Tab=Products

http://www.ellsworth.com/display/productdetail.html?productid=2067&Tab=Products

http://www.cotronics.com/vo/cotr/ea_electricalresistant.htm

b.) mix with a metal similar to Th-232.

c.) construct bed of 0.4 mm nails. Look for 0.4 mm diameter pins.

7/31/2009

New vendor for carbon paste.

http://www.electrapolymers.com/productItem.asp?id=33

The data sheet does not show any information about the thickness of the paste.

The company has a distributor in the usa (877)-867-9668. A phone call is expected on Sat. 8/3/2009 about the availability of the product.

TGEM Mask Design

Coating U-238 or Th-232 is essential for neutron detection in the range 2-14 MeV, but THGEM contains holes that should be protected from any coating material. So, a mask is designed to cover these holes. The holes are in drilled to be on the corners of hexagonal of 1mm side length as in the figure:

The mask is made of stainless steel, 10 um laser tolerance with cut the plate to get the shape in the figure:

Please look at the following files for more details:

Make number bold black font. Add color so it is clear that they are holes in a material.

File:Copper foil 04mm.pdf

File:Holes mask together.pdf

TGEM_Mask_Design

P_D

Performance of THGEM as a Neutron Detector

H_Proposal_Defense

Vendor

Thick Film Screen Printers

http://www.sciquip.com/browses/browse_Cat.asp?Category=Screen+Printers

http://www.marubeni-sunnyvale.com/screen_printing.html

Go Back TGEMS

tektronix oscilloscope

134.50.3.73