BriansRanLogbook

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Revision as of 00:49, 9 May 2023 by Rasmbria (talk | contribs)
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This is where I write down what I'm doing

1/13/23 : Turned on HpGe HV to 1500 and learned about analog to digital signal processing

detected signal rate -vs- HpGe Voltage

HpGe Detector

HPGe Counts vs Voltage Cs-137 Source
High Voltage (V) Counts (with source) Counts (no source)
1492.67 1532.5 ± 36.67 167.5 ± 7.78
799.15 1336.5 ± 2.12 149.4 ± 34.65
396.83 1193.5 ± 54.48 127.5 ± 7.78
197.19 1035.5 ± 40.31 121 ± 4.24
4.88 562.5 ± 2.12 332 ± 35.36
HpGe Detector Voltage vs Counts graph.jpg

05/02/2023 Amplifier Course Gain: 2 High Voltage: 1500V

run 7343 Disc Thresh:0.588V

run 7345 Disc Thresh: 0.500V

run 7346,7347 Disc Thresh: 0.425V

Background Subtracted graph for Cs-137

run 7348, Disc Thresh: 0.351V

run 7351, Cs-137 source, Disc Thresh: 0.306V run 7353, EU-152 source Disc Thresh: 0.306V

He3 Tube

1/27/23 : Turned on He3 detector, adjusted to find counts with Cf source in containment and out of containment

2/3/23 : Same as 1/27, adjusting discriminator voltage and recording counts with Cf-252 source. Encountered strange effects of higher counts with source away at low QD voltage. Sets of measurements notably inconsistent.

He3 Counts vs Voltage (1208 HV)
Discriminator Voltage (V) Counts/10s (no source) Counts/10s (with source)
2.003 4.4 ± 1.67 97.0 ± 8.49
1.788 4.8 ± 1.09 108.2 ± 10.89
1.503 5.4 ± 2.22 105.7 ± 8.63
1.227 7.9 ± 3.14 109.8 ± 9.34
1.009 89.9 ± 7.87 234.1 ± 20.06
0.799 2656 ± 251.1 2447 ± 183.0
0.485 55479 ± 1325 48360 ± 1938
Plateau graph for He3 tube at 1208V

2/10/23 Same procedure as 2/3/23, just changing HV applied to He3 detector to values of 1300V then 1100V.


He3 Counts vs Voltage (1100 HV)
Discriminator Voltage (V) Counts/10s (no source) Counts/10s (with source)
1.971 4.6 ± 2.37 107.7 ± 13.17
1.775 7.7 ± 2.11 100 ± 10.70
1.486 5.5 ± 2.32 104.8 ± 12.79
1.248 4.7 ± 2.00 99.6 ± 7.09
1.013 75.2 ± 12.17 171 ± 12.82
0.762 3074 ± 143.0 2833 ± 894.7
0.509 19658 ± 424.6 40290 ± 2402
Plateau graph for He3 tube at 1100V
He3 Counts vs Voltage (1300 HV)
Discriminator Voltage (V) Counts/10s (no source) Counts/10s (with source)
1.971 5.4 ± 1.78 111.3 ± 9.97
1.773 5.3 ± 1.89 97.3 ± 7.70
1.524 7.1 ± 4.51 99.7 ± 11.78
1.275 12.2 ± 3.55 117.3 ± 23.11
0.993 177.7 ± 8.18 351.9 ± 28.71
0.784 2691.2 ± 114.7 2763.7 ± 126.2
0.485 50346 ± 3831 53920 ± 4354
Plateau graph for He3 tube at 1300V

03/31/2023

  • Analyzed the plateau graphs.
  • Began taking plateau measurements between a discriminator voltage range of about 1.000V and 1.250V to determine where the noise is cut from the signal.
  • Got abnormal fluctuations in counts.

04/04/2023

  • Worked with Dr. Forest to tune the He3 detector such that the peak height of the signal could be read by the computer.
  • Set up the computer to read from the peak sensing ADC and start taking measurements.
  • Started a background measurement to run overnight.

04/05/2023

  • Ended the background measurement.
  • Took a new measurement, this time with source out.

04/07/2023

  • Worked with Dr. Forest to graph the two measurements and to create a graph of the source out measurement minus the background measurement.
  • Began re-tuning the detector in order to repeat the process once more.

04/11/2023

  • Finished tuning the detector and took another source out measurement. The discriminator threshold this time was at 3.660V.
  • Completed a second background measurement.

04/12/2023

  • Started a new plateau measurement by taking a measurement with the source out and viewing the graph in root.
  • Since the He3 detector was readjusted the new point where noise is cut from the signal has shifted, after some measurements it was determined to now be somewhere between 1.900 and 2.000 instead of the window from 03/31/2023.
  • Took a source out measurement at a discriminator threshold 1.900V.

04/18/2023

  • Before starting measurements the GUI displayed an error "Lost Connection to the Platform." Had to restart the process.
  • After adjusting the discriminator threshold to 1.927V and taking a source out measurement, the data file produced no results when graphing the data in ROOT. Was unable to determine the reason for this. It's possible the width of the logic pulse was accidentally adjusted while while changing the disc voltage or that some adjustment was made to their position so that the computer does not have enough time to read out the measurement. Will check the detector is correctly adjusted and ask Dr. Forest when he returns if that is not the problem.

04/19/2023

  • Was unable to determine the reason that the data file was reading out incorrectly. Will have to wait for Dr. Forest to help understand and fix the problem.
  • Attempted to start creating background subtracted graphs in ROOT for the measurements already taken.

04/20/2023

  • Finished the background subtracted graphs.
  • Looked at the peak sensing ADC one more time without success.

05/08/2023

  • Started by doing a coincidence experiment using two plastic scintillators, Jacinda and Michele. We placed the wider one, Jacinda, on a table and connected it to a high voltage power supply at about 1200V as well as the oscilloscope on scope 3.
  • Michelle, the thinner scintillator, was connected to another high voltage power supply at about 1050V and connected to scope 4 on the oscilloscope. Both power supplies had negative polarity. Michelle was held above Jacinda and the scope was used to observe coincidence counts. It did appear that we were may have been receiving more pulses through Jacinda that did not pass through Michelle than expected.
  • Next, Michelle was connected to a discriminator and sent to a scalar. At the discriminators lowest setting of 0.306V, no counts from background sources were observed. A Cs-137 source was brought close to the scintillator and no counts were observed. We then tried sending Michelle's signal through a spec amp and timing filter amp and then through the discriminator and scalar. Doing this did cause the source in/source out signals to become distinguishable.
  • Tried again to send Michelle directly to a discriminator unamplified with a high voltage of 1000V and did observe background counts. The error was likely due to sending the signal through an timing filter amp unnecessarily. The Cs-137 source was brought close to the scintillator again and a noticeable difference in counts between the source in/source out signals was observed.
Source in/source out counts for the Michelle scintillator (1000V)
Source in counts (Hz) Source out counts (Hz)
112 2
105 2
103 2
122 2
99 3
128 3
98 5
117 4
127 1
117 0
Average: 112 ± 11.15 Average: 2.4 ± 1.43
Caption text
Disc Threshold (V) Source in (counts/100s) Source out (Counts/100s)
0.318 V 10578 271
0.354 V 10837 262
0.410 V 9908 234
0.450 V 9198 213
0.503 V 8473 210
0.554 V 8152 183
0.604 V 7342 154
0.653 V 6609 159
0.702 V 6076 158
0.755 V 5427 139
0.805 V 4943 140
0.854 V 4500 124
0.904 V 3686 130
0.950 V 3289 131
1.004 V 2533 112
1.055 V 2046 126
1.104 V 1464 108
1.149 V 1148 112
1.201 V 825 118
1.249 V 553 108
1.299 V 385 87
1.355 V 230 94
1.400 V 210 91
1.450 V 135 89
1.500 V 111 86
1.555 V 109 82