NAA SolarPanel

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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

Mg Rate 06042018.png

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