CH PAS He3 BorAl Attenuation Study

Experimental Setup

Attenuation Measurements Setup
Poly box to contain Cf-252 source for attenuation measurements	[[File:|400px|thumb|none|He3 tube mounting for attenuation measurements ]]	[[File: |300px|thumb|none| ]]
[[File:|300px|thumb|none| ]]	Top down view of Cf-252 source in place, ready to be covered by top sheet of virgin poly	[[File: |300px|thumb|none| ]]

The He3 detector is shrouded in BorAl, in a triangular configuration with +1250V to the pre-amp (this voltage is based on previous work by Jeff Burggraf and David Friant).

The thermalizing box is designed as regular poly surrounding the Cf-252 source on all sides except the side in the direction of the He3 tube.

The thermalizer is considered a regular poly sheet that can be slid in and out of the experimental setup.

The detector is ~30cm from the Cf-252 source. This allows for enough distance to insert 8" (20.32cm) of green borated poly, a 1" (2.54cm) thermalizing sheet, and still have the BorAl in the correct position.

No lead was included in the setup as it was not necessary.

The discriminator threshold was not changed during this experiment as it is in the center of the plateau work done by David Friant. See plot below.

Credit: David Friant. This plot is source in and source out He3 tube plateau measurements which were used to base discriminator and bias voltages for attenuation measurements.

Measurements

Background Measurements

I will be performing background runs overnight due to the low amount of background counts. This is necessary to get an acceptable level of uncertainty in the measurements as the count rate looks to be on the order of .5Hz.

The first run background run is taking place the evening of 6/25/21 and will end the following day.

Background run lasted for 60000 seconds and took place overnight. Run ended at approximately 11:45am 6/26/21

1250V Source Out Data
Run Number	Configuration	Discriminator Threshold (mV)	Cf-252 Button Source	Counts	Run Time (Sec)	Count Rate (Hz)	Uncertainty
1	Detector on BorAl at +1250V	255	No	722	60000

Source In

No thermalizer, no borated poly, just BorAl shielding around detector

1250V Source In Data
Run Number	Configuration	Discriminator Threshold (mV)	Cf-252 Source	Counts	Run Time (Sec)	Count Rate (Hz)	Uncertainty
1	Detector on BorAl at +1250V	255	Yes	236	300
2	Detector on BorAl at +1250V	255	Yes	263	60
3	Detector on BorAl at +1250V	255	Yes	251	60
4	Detector on BorAl at +1250V	255	Yes	203	60
5	Detector on BorAl at +1250V	255	Yes	218	60

Source In with Thermalizer

Thermalizer, no borated poly, & BorAl shielding around detector

1250V Source In Data
Run Number	Configuration	Discriminator Threshold (mV)	Cf-252 Source	Counts	Run Time (Sec)	Count Rate (Hz)	Uncertainty
1	Detector on BorAl at +1250V	255	Yes		300
2	Detector on BorAl at +1250V	255	Yes		60
3	Detector on BorAl at +1250V	255	Yes		60
4	Detector on BorAl at +1250V	255	Yes		60
5	Detector on BorAl at +1250V	255	Yes		60

Green Poly without Thermalizer

1" Green poly (one sheet), no thermalizer

1250V source in
Run Number	Configuration	Discriminator Threshold (mV)	Cf-252 Source	Counts	Run Time (Sec)	Count Rate (Hz)	Uncertainty
1	Detector on poly at +1250V	255	Yes		300
2	Detector on poly at +1250V	255	Yes		300
3	Detector on poly at +1250V	255	Yes		300
4	Detector on poly at +1250V	255	Yes		300
5	Detector on poly at +1250V	255	Yes		300

2" Green poly (one brick) no thermalizer

1250V source in
Run Number	Configuration	Discriminator Threshold (mV)	Cf-252 Source	Counts	Run Time (Sec)	Count Rate (Hz)	Uncertainty
1	Detector on poly at +1250V	255	Yes	154	300
2	Detector on poly at +1250V	255	Yes	163	300
3	Detector on poly at +1250V	255	Yes	150	300
4	Detector on poly at +1250V	255	Yes	125	300
5	Detector on poly at +1250V	255	Yes	154	300

3" Green poly (one brick & sheet) no thermalizer

1250V source in
Run Number	Configuration	Discriminator Threshold (mV)	Cf-252 Source	Counts	Run Time (Sec)	Count Rate (Hz)	Uncertainty
1	Detector on poly at +1250V	255	Yes		300
2	Detector on poly at +1250V	255	Yes		300
3	Detector on poly at +1250V	255	Yes		300
4	Detector on poly at +1250V	255	Yes		300
5	Detector on poly at +1250V	255	Yes		300

4" Green poly (two bricks) no thermalizer

These measurements need to be redone as <100 counts is higher than 10% uncertainty

300 sec runs

1250V source in
Run Number	Configuration	Discriminator Threshold (mV)	Cf-252 Source	Counts	Run Time (Sec)	Count Rate (Hz)	Uncertainty
1	Detector on poly at +1250V	255	Yes	74	300
2	Detector on poly at +1250V	255	Yes	65	300
3	Detector on poly at +1250V	255	Yes	71	300
4	Detector on poly at +1250V	255	Yes	61	300
5	Detector on poly at +1250V	255	Yes		300

600 sec runs

1250V source in
Run Number	Configuration	Discriminator Threshold (mV)	Cf-252 Source	Counts	Run Time (Sec)	Count Rate (Hz)	Uncertainty
1	Detector on poly at +1250V	255	Yes	153	600
2	Detector on poly at +1250V	255	Yes	134	600
3	Detector on poly at +1250V	255	Yes	124	600
4	Detector on poly at +1250V	255	Yes	145	600
5	Detector on poly at +1250V	255	Yes	133	600

6" Green poly (three bricks) no thermalizer

1250V source in
Run Number	Configuration	Discriminator Threshold (mV)	Cf-252 Source	Counts	Run Time (Sec)	Count Rate (Hz)	Uncertainty
1	Detector on poly at +1250V	255	Yes	115	900
2	Detector on poly at +1250V	255	Yes		900
3	Detector on poly at +1250V	255	Yes		900
4	Detector on poly at +1250V	255	Yes		900
5	Detector on poly at +1250V	255	Yes		900

8" Green poly (four bricks) no thermalizer

1250V source in
Run Number	Configuration	Discriminator Threshold (mV)	Cf-252 Source	Counts	Run Time (Sec)	Count Rate (Hz)	Uncertainty
1	Detector on poly at +1250V	255	Yes		300
2	Detector on poly at +1250V	255	Yes		300
3	Detector on poly at +1250V	255	Yes		300
4	Detector on poly at +1250V	255	Yes		300
5	Detector on poly at +1250V	255	Yes		300

Green Poly with Thermalizer

1" Green poly, with thermalizer

1250V source in
Run Number	Configuration	Discriminator Threshold (mV)	Cf-252 Source	Counts	Run Time (Sec)	Count Rate (Hz)	Uncertainty
1	Detector on poly at +1250V	255	Yes		300
2	Detector on poly at +1250V	255	Yes		300
3	Detector on poly at +1250V	255	Yes		300
4	Detector on poly at +1250V	255	Yes		300
5	Detector on poly at +1250V	255	Yes		300

2" Green poly (one brick) with thermalizer

1250V source in
Run Number	Configuration	Discriminator Threshold (mV)	Cf-252 Source	Counts	Run Time (Sec)	Count Rate (Hz)	Uncertainty
1	Detector on poly at +1250V	255	Yes		300
2	Detector on poly at +1250V	255	Yes		300
3	Detector on poly at +1250V	255	Yes		300
4	Detector on poly at +1250V	255	Yes		300
5	Detector on poly at +1250V	255	Yes		300

3" Green poly (one brick & sheet) with thermalizer

1250V source in
Run Number	Configuration	Discriminator Threshold (mV)	Cf-252 Source	Counts	Run Time (Sec)	Count Rate (Hz)	Uncertainty
1	Detector on poly at +1250V	255	Yes		300
2	Detector on poly at +1250V	255	Yes		300
3	Detector on poly at +1250V	255	Yes		300
4	Detector on poly at +1250V	255	Yes		300
5	Detector on poly at +1250V	255	Yes		300

4" Green poly (two bricks) with thermalizer

1250V source in
Run Number	Configuration	Discriminator Threshold (mV)	Cf-252 Source	Counts	Run Time (Sec)	Count Rate (Hz)	Uncertainty
1	Detector on poly at +1250V	255	Yes		300
2	Detector on poly at +1250V	255	Yes		300
3	Detector on poly at +1250V	255	Yes		300
4	Detector on poly at +1250V	255	Yes		300
5	Detector on poly at +1250V	255	Yes		300

6" Green poly (three bricks) with thermalizer

1250V source in
Run Number	Configuration	Discriminator Threshold (mV)	Cf-252 Source	Counts	Run Time (Sec)	Count Rate (Hz)	Uncertainty
1	Detector on poly at +1250V	255	Yes		300
2	Detector on poly at +1250V	255	Yes		300
3	Detector on poly at +1250V	255	Yes		300
4	Detector on poly at +1250V	255	Yes		300
5	Detector on poly at +1250V	255	Yes		300

8" Green poly (four bricks) with thermalizer

1250V source in
Run Number	Configuration	Discriminator Threshold (mV)	Cf-252 Source	Counts	Run Time (Sec)	Count Rate (Hz)	Uncertainty
1	Detector on poly at +1250V	255	Yes		300
2	Detector on poly at +1250V	255	Yes		300
3	Detector on poly at +1250V	255	Yes		300
4	Detector on poly at +1250V	255	Yes		300
5	Detector on poly at +1250V	255	Yes		300

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CH He3 Attenuation Measurements

PAS Experiment Attenuation Measurements

PAS_He3_Detector

PAS_Experiment