NAA SolarPanel

PAA_Research

SolarPanel A Irradiation on Jack

Apparatus

Running conditions

Irradiated on Jack by placing samples just above the Radiator as shown in the picture.

Beam parameters: Irradiation Date : 5/23/18

Start Time: 09:07:30

Stop Time: 11:07:30

[math]T_{Irradiation} = 120 min [/math]

Rep Rate=300 Hz

I = 98 mA

Pulse Width = 10 usec

E = 38 MeV

The solar panel current output dropped 1 mA per hour during irradiation. The cove was too dark to produce a signal from ambient light. The observed signal was completely due to the electron beam.

Photonuclear cross section for Tungsten

The cross section for photon knockout of a neutron from several Tungsten Isotopes is given in the article below File:NucTech Volume 168 2009.pdf

and the figure below

File:GammaNOnW 061918.png

Neutron Energy Spectrum

A simulation of 40 MeV electrons on thick Tungsten produces the Neutron energy spectrum below, overlay with the U-235 fission spectrum

File:NeutronEnergySpectFrom40MeVElectronsOnTungsten 061918.png

neutron Flux precitions

Radiation Damage Study of Materials The modified neutron source capable of producing 1014 n/cm2s, will generate ~2 DPA/year in steels (HT9, 304L, MA956). To achieve DPA levels of interest (>0.1 DPA at <400 °C) it would take about 20 days of neutron irradiation.

In File name:10uC_Cs_Mn_SolarPan_DetD_55.5cm_002.lst

Measurements started at 14:45:38, 2:38:08 (158 min, 9488 sec) after irradiation ended,

Add 9488 seconds to time below to get time since irradiation

Time (sec)	Sample
0	Cs-137 (661 keV line) #64121 55.5 cm away from face
360	Mn sample (1.7 g, 1.5 cm x 1.5 cm square, 847 keV) 55.5 cm away from face
690	Thorium Rods on face of detector
1020	Solar Panel A 55.5 cm away from face
1410	Cs-137 #129792 55.5 cm away from face
1820	Mn sample (847 keV) 55.5 cm away from face
2230	Cs-137 #129792 55.5 cm away from face (0.54% deadtime)
2560	Solar Panel A 55.5 cm away from face (0.55% deadtime, 300 Hz DAQ rate)
2880	Cs-137 (661 keV line) #64121 55.5 cm away from face (1.1% deadtime, 350 Hz)
3070	Mn sample (847 keV) 55.5 cm away from face (13 % deadtime, 4600 Hz)
3330	Ignore (Mn source was too close) Cs-137 #129792 15 cm away from face(6 % deadtime, 2000 Hz)
3600	Cs-137 #129792 15 cm away from face(.5 % deadtime, 200 Hz)
4000	Solar Panel A 15 cm away from face (2 % deadtime, 880 Hz DAQ rate)

Check out Solar panel channels

root [24] MPA->Draw("evt.Chan>>(496,0,496)","evt.Sec> 2560 && evt.Sec<2800 && evt.Chan >306 && evt.Chan < 311");

root [25] MPA->Draw("evt.Chan>>(496,0,496)","evt.Sec> 1020 && evt.Sec<1260 && evt.Chan >306 && evt.Chan < 311");

Calibration

Source	Energy (keV0	Channel
Th Rod	238.8 (highest peak)	487.2 +/- 1.1
Th Rod	338.8 (4th highest)	690.4 +/- 1.3
Th Rod	511
Th Rod	583.4 (2nd highest peak)	1189.6 + / 1.2
Cs-137	661.7	1350
Th Rod	911.2 (3rd highest)	1858.3 +/- 1.4
Th Rod	2614.6	5331.0 +/- 2.2

Energy (keV) = (0.065 +/- 1.34) + Channel*(0.490287 +/- 0.001174)

MPA->Draw("evt.Chan*(0.490) >>(6096,0,6096)","evt.Sec > 690 && evt.Sec < 1000");

Solar Panel Lines of interest

491, 528, 552.5, 847 , 1097 , 1293, 1303, 1810, 1997

In File name:10uC_Cs_Mn_SolarPan_DetD_55.5cm_003.lst

The measurement below started at 16:24:09, 4:16:39 after irradiation ended

Add 15399 seconds to time below to get time since irradiation

Time (sec)	Sample
0	Thorium Rods on face of detector (2% deadtime, 750 Hz)
350	Mn sample (847 keV) 55.5 cm away from face (12% deadtime, 3800 Hz)

Ended measurements at (9:34 am Thursday, 5/24/18)

[math]{55 \atop 25\; }Mn (n,\gamma){56 \atop 25\; }Mn[/math]

[math]T_{1/2} = 2.579 hr[/math]

Reference for Mn half life of 2.5785 hrs

https://journals.aps.org/prl/pdf/10.1103/PhysRevLett.60.2246

Rate Estimates

Activation Equations

[math]R=N \sigma \phi[/math]

R = Activations /cm^3/s

N = # atoms / cm^3

\sigma = Crossection (cm^2)

\phi = nuetron flux density ( neutrons/cm^2/s)

Observed Activity

Mass of Sample = 1.6992 g

Surface area 1 cm^2

30 cm from radiator

After 2 hours of irradiation the count rate from the Manganese witness foil was 250 Hz

Neutron capture cross section for manganese

https://journals.aps.org/prc/pdf/10.1103/PhysRevC.18.2079

Misnamed article below

File:PHYSRevL60 2246.pdf

Min Energy (keV)	Max Energy (keV)	Cross Section (mb)
3	6	81.3
6	9	186.6
9	12	67.1
12	15	27.7
15	20	43.6
20	30	44.6
30	40	44.7
40	50	28.2
50	60	26.0
60	80	21.5
80	100	16.3
100	120	14.3
120	140	15.2
140	160	8.3
160	180	8.6
180	200	8.3
200	220	6.5
220	240	6.3
240	260	5.6
260	280	5.6
280	300	6.6
300	320	5.8
320	340	5.7
340	360	5.8
360	380	4.3
380	400	5.1
400	420	5.9
420	440	5.0
440	460	5.6
460	480	5.6
480	500	4.6
500	550	4.2
550	600	4.8
600	650	3.8
650	700	4.3

PAA_Research