Neutron TGEM Detector Abdel

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2012

2011

2010

2009

THGEM#9 Counting Experiment test 1/4/13

The same setup above for THGEM#9 is used for a counting experiment.

The aim is to compare the number of counts in an hour for three different cases:

case 1-The alpha source's shutter is closed.

case 2- The alpha source's shutter is closed and a gamma source (Co-60) placed on the detector's entrance window.

case 3-The alpha source's shutter is open the gamma source is removed

case 4-The alpha source's shutter is open and a gamma source (Co-60) is placed on the detector's entrance window.

V_cathode THGEM_1T THGEM_1B [math]\Delta V1 [/math] THGEM_2T THGEM_2B [math]\Delta V2 [/math] THGEM_3T THGEM_3B [math]\Delta V3 [/math]
4200 2950 2450 500 1950 1200 750 950 100 850


Experimental Setup

Trigout-> 474 ortec timing filter amp. -> EGG&G ESN CF4000-01 discriminator (5 mV threshold) -> tennelec TC534 counter and timer.


case # case 1 case 2 case 3
counts/hr 462 2400 2759

According to the number of counts in each case:

1- The detector detects cosmic rays (noise). (assuming the shutter stops all the alpha particles without any ionization)

2- The detector is sensitive to gamma rays (2400-462 = 1938)

3- The detector is sensitive to alpha particles (2759-462 = 2297) considering the same assumption above.


Discriminator level-count level relationship

V_cathode THGEM_1T THGEM_1B [math]\Delta V1 [/math] THGEM_2T THGEM_2B [math]\Delta V2 [/math] THGEM_3T THGEM_3B [math]\Delta V3 [/math]
4359 2950 2450 500 1950 1200 750 985 100 850

The following table represent the discriminator level and the count rate that is measured in 10 minute time interval with the shutter OPEN and 474 ortec timing filter amp. amplification is x6.


discriminator level Counts/min
(mv) Trial 1 trial 2 Trial 3 Trial 4 trial 5 Ave [math]\pm[/math] err
5 80.7 104.2 67.4 64.5 72.8
7 96.6
8
9 36.8
10
12 11.2
13
15 5.1
18 3.7
20 3.2
50 0
75 0.1
100 0

Counting Experiment using Leading Edge discriminator (Lecroy 623b)

The same setup above for THGEM#9 is used for a counting experiment.

The aim is to compare the number of counts for three different cases:

case 1-The alpha source's shutter is closed.

case 2- The alpha source's shutter is closed and a gamma source (Co-60) placed on the detector's entrance window.

case 3-The alpha source's shutter is open the gamma source is removed

case 4-The alpha source's shutter is open and a gamma source (Co-60) is placed on the detector's entrance window.

V_cathode THGEM_1T THGEM_1B [math]\Delta V1 [/math] THGEM_2T THGEM_2B [math]\Delta V2 [/math] THGEM_3T THGEM_3B [math]\Delta V3 [/math]
4200 2950 2450 500 1950 1200 750 950 100 850

The amplifier amplification affect the count rate, the follwing table shows the effect as the discrimination level is 1.19V :

Amplification Count rate (Count/min)
x10 1.37x10^7
X6 1151
x4 9
x2 1
x1 1

based on the above table, the amplification is chosen to be x6 for the measurement below.

case # case 1 case 2 case 3 case 4 Notes
counts/min 1.55 x 10^7 disc. level = 0.30V (700 mV sq.p-p)
counts/min 2.08 x10^6 disc. level = 0.53 mV (1.8V sq.p-p)
counts/min 6902 disc. level = 1.1 V (3V sq.p-p)
counts/min 3222 disc. level = 1.2 V
counts/min 1469 disc. level = 1.3 V
counts/min 680 disc. level = 1.4 V
counts/min 113 disc. level = 1.5 V
counts/min 64 84 disc. level = 1.62 V (4V sq.p-p)
counts/min 10 11 disc. level = 1.7 V
counts/min disc. level = 1.8 V
counts/min 10 9 disc. level = 1.9 V
counts/min 7 9 disc. level = 2 V

Alpha-Beta detector counter

GEM before modification

GEM detector was operated without U-233 source inside the chamber, the detector's counting rate relationship with the applied voltage on the cathode was investigated and the result is shown by the following figure:

GEM CATH BEFORE.png


In the counting experiment, P.S. discriminator was used to discriminate againt the noise, the relationship between the count rate and the discrimination level (without changing the applied voltages on GEM cards and the cathode. The data is represented by the following figure:

GEM DISC BEFORE.png

The detector signal detected when the voltage on GEM HV-circuit was 2800V, but it was lower the noise, but raising up the voltage to 3000 V made the signal higher than the noise. So all the previous measurements observed ast he GEM HV-circuit was 3000V.

GEM after modification

A new cathode with thin layer of U-233 and its a FR4 shutter were added to the chamber, the distance of cathode is 8mm from the first GEM card, the distances between the GEM cards have equal distances to the ones before the modifications.

The VFAT connectors are connected together to provide the signal of the signal of the readout plate.

A signal is observed (on trigout and readout)as the voltage magnitude on the GEM HV-voltage circuit is 2800V, and the cathode is 3100V.

Prelimanry count rate measurements were recorded using 474 time filter amplifier, P.S. 710 discrimonator (at 0.7V) and a counter in the following table:

Shutter location Counts/min
close 2049 2500
open 6561 6360

The high rate of counts observed as the sutter is close is due to the U-233 beta decay as shown in the figure:

U-233 decay.gif

Two Counter Counting Experiment

Two counters were used for counting the detector signal after installing U-233 inside the detector. The signal detected by the trigout was an input for P.S. eight channel variable gain amplifier (model 777) that had two outputs fed two types discriminators; EG&G-EN CF4000 Constant Fraction Discriminator and P.S. octal leading edge discriminator (model 710). The discrimination level of each of them allowed one of the counters (ortec 875) to count for all the amplified signal pulses produced as the shutter was close, simultaneously, the second counter to count for them as the shutter was open. (The CFD D.V. was 0.025V and 6x 474 Ortec TFA , LED D.V. was 1.52V and 1x TFA)


Due to the lower pulse amplitude for the alpha particles the higher one for negative beta, decrease the detector gain may help in counting for alphas and fission fragments without counting for beta particles. Or we can use Ortec 552 (pulse shape analyzer and timer) with ortec 460 (delay shaping line amplifier).


Counting started by the lowest voltage alpha signal is observed (2.6 kV, 2.9 kV), an ortec 474 is used and it amplifies the signal up to 6x.A leading edge P.S. 710 octal discriminator is used with a discrimination level of 150 mV.

GEM performance data graphs

Without a source

DISC COUNTS CLOSESHUTTER.png

DISC COUNTS OPENSHUTTER.png

With a source

DISC COUNTS CLOSESHUTTER Cf252.png

DISC COUNTS OPENSHUTTER Cf252.png


Shutter Open (Source on - Source off)/Source on vs. discrimination level

S open source on-off ratio 2600.png


Ratio amp 2600.png

Ratio disc 2600.png


Ratio disc 2600 stable.png

The uncertainty is calculated as the following:

u=on v=off


[math]Y = U-v/u \,,\,\,\,\,\,\, x = u-v [/math]


[math] dy = y[(dx)^2/x^2 +(du)^2/u^2]^{0.5} [/math]


[math] dx = [(du)^2+ (dv)^2]^{0.5} [/math]


[math] d y = y[(du)^2+(dv)^2/(u^2-v^2)+ (du/u)^2]^{0.5 }[/math]

Run List1 GEM, Cathode 2.6, 2.9kV

/home/daq/CODA/CODAreader/ROOT_V5.30/V775mV792/evio2nt -fr4685.dat > /dev/null

The voltage of the Cathode is 2.9 kV and of the GEMs is 2.6 kV.

The amplifier is on x6 level fine gain which will amplify the detector signal to 33.5 times (6.56+_ 0+_ V/196 +_ 0.6mV).


Run # discrimination level ortec 474 amplification Start Date End Date Shutter Position Source pulse snapshot picture and Comparison notes
4662 0.25 4 17:00 04/04 10:00 04/05 open off R4664 0.25disc ortex4.png
4663 1.1 4 10:00 04/05 13:14 04/05 open off R4664 1.1disc ortex4.png
4664 0.9 4 13:14 04/05 16:48 04/05 open off R4664 0.9disc ortex4.png
4665 0.9 4 17:11 04/05 20:21 04/05 open on R4664 0.9disc ortex4 sourceOn.png
4666 1.1 4 20:26 04/05 21:38 04/05 open On R4664 1.1disc ortex4 sourceOn.png
4668 0.25 6 21:47 04/05 7:45 04/06 open off compare ampx4 (blue) and ampx6 (red)Comp r4662r4662 0.25disc ortex4x6.png R4664 0.25disc ortex6.png ortec #of counts 1.37M, ADC # of counts 676056
4670 0.25 4 11:00 04/05 11:55 closed On
4671 0.25 6+ fine level 3 12:28:38 04/06 12:38 closed off
4672 0.25 10 12:38:28 04/06 12:42 closed off
4673 0.25 6+fine level 5 12:42:59 04/06 12:47:30 closed off
4674 0.25 6+fine level 4.5 12:48:18 04/06 13:01:50 closed Off
4675 0.25 6+fine level 4.5 13:03:35 04/06 21:00:55 closed Off R4675 0.25disc ortex6.png
4676 0.25 6+fine level 4.5 21:06:07 04/06 09:27:29 04/07 open Off

R4676 0.25disc ortex6 shutteropen.pngR4676 0.25disc ortex6 compshutteropen close.png compare shutter open (blue) and shutter close (red)

4677 0.25 6+fine level 4.5 09:31:03 04/07 21:31:07 04/07 open on

R4676 0.25disc ortex6 shutteropen sourceOn.pngR4677 0.25disc ortex6 compshutteropen sourceon on off.png compare shutter open as the source is off(blue) and as it is on (red)

4678 0.25 6+fine level 4.5 21:32:10 04/07 close on R4678 0.25disc ortex6 shutterclose sourceon.png
4679 0.25 6+fine level 4.5 10:39:19 04/08 22:22:21 04/08 close off R4678 0.25disc ortex6 shutterclose sourceff.png
4680 0.25 6+fine level 4.5 22:26:10 04/08 10:05:07 04/09 open off R4680 0.25disc ortex6 shutteropen sourceff.png
4681 0.25 6+fine level 4.5 10:08:59 04/09 14:26:12 04/09 open on R4681 0.25disc ortex6 shutteropen sourceon.png
4682 0.25 6+fine level 4.5 14:30:43 04/09 06:51:39 04/10 open off R4682 0.25disc ortex6 shutteropen sourceoff.png
4683 0.25 6+fine level 4.5 06:56:00 04/10 16:07:36 04/10 close off R4683 0.25disc ortex6 shutterclose sourceoff.png

compare r4683 (red) and r4679 (blue) as both have hsutter is close without source Comp r4683 r4679S 0.25disc ortex6 shutterclose sourceoff.png

4684 0.25 6+fine level 4.5 16:10:59 04/10 10:46:10 04/11 close off R4684 0.25disc ortex6 shutterclose sourceoff.png

compare r4684 (red) and r4683 (blue) as both have hsutter is close without source Comp r4684 r4683S 0.25disc ortex6 shutterclose sourceoff.png

4685 0.25 6+fine level 4.5 10:50:52 04/11 07:06:55 04/12 open off R4685 0.25disc ortex6 shutteropen sourceoff.png Comp 4676g 4682r 4685b.png r4685 (blue) has the two peaks close in height compared to the other two runs (r4682(red) and r4676(green), which indicates that the source has a new source of charge as result of a decay to one of the short half life alpha emitting daughters.
4686 0.25 6+fine level 4.5 07:37:34 04/12 19:50:55 04/12 close off R4686 0.25disc ortex6 shutteropen sourceoff.png Comp r4686b r4684r r4679g.png comparing three runs together r4686(blue),r4684(red), and r4679 (green). they are all record the charge as the shutter is close. it is noticed that the last run reproduced the expected peak that was observed before in r4679
4687 0.25 6+fine level 4.5 19:54:17 04/12 06:59:28 04/13 open off R4687 0.25disc ortex6 shutteropen sourceoff.png
4688 0.25 6+fine level 4.5 07:01:35 04/13 10:31:31 04/13 open off R4688 0.25disc ortex6 shutteropen sourceoff.png
4689 0.25 6+fine level 4.5 10:33:13 04/13 19:09:56 04/13 close off R4689 0.25disc ortex6 shutterclose sourceoff.png Comp 4686r 4689b 4685b.png the new peak (in 4688) was partial blocked by the shutter but the tail is still high compared to 4686.
4690 0.25 6+fine level 4.5 19:26:44 04/13 06:41:16 04/14 open off R4690 0.25disc ortex6 shutteropen sourceoff.png
4691 0.25 6+fine level 4.5 21:15:44 04/13 09:58:16 04/14 open off R4691 0.25disc ortex6 shutteropen sourceoff.png
4692 0.25 6+fine level 4.5 10:05:14 04/15 16:34:50 04/15 open off R4692 0.25disc ortex6 shutteropen sourceoff.png back to the normal spectrum as the shutter is open
4693 0.25 6+fine level 4.5 16:41:05 04/15 07:29:25 04/15 close off R4693 0.25disc ortex6 shutterclose sourceoff.png
4694 0.25 6+fine level 4.5 07:39:30 04/16 14:51:29 04/16 close off R4694 0.25disc ortex6 shutterclose sourceoff.png
4694 battery R4694 battery.png battery charged collected by the ADC without any electronics used1
4695 battery R4695 battery MINmodules.png battery charged collected by the ADC as the battery charge passes through the NIM-modules
4914 0.57 6+fine level 4.5 13:39:25 04/30 07:26:42 05/01 open off R4914 0.57disc ortex6 shutteropen sourceoff.png
4917 0.36 6+fine level 4.5 10:00:21 05/01 14:43:05 05/01 open off R4917 0.36disc ortex6 shutteropen sourceoff.png
4918 0.36 6+fine level 4.5 14:53:41 05/01 13:56:05 05/01 open on R4918 0.36disc ortex6 shutteropen sourceon.png
4935 0.36 6+fine level 6 16:38:38 05/01 07:30:04 05/02 open off R4935 0.36disc ortex6 shutteropen sourceoff.png
4936 0.36 6+fine level 6 07:34:01 05/02 15:02:30 05/02 close off R4936 0.36disc ortex6 shutterclose sourceoff.png
4989 0.36 6+fine level 6 11:47:06 05/03 15:40:47 05/03 close off R4989 0.36disc ortex6 shutterclose sourceoff.png 10Hz
4990 0.36 6+fine level 6 15:44:10 05/03 22:36:28 05/03 open off R4990 0.36disc ortex6 shutteropen sourceoff.png 10Hz
4992 0.36 6+fine level 6 22:57:47 05/03 08:51:26 05/04 close off R4992 0.36disc ortex6 shutterclose sourceoff.png 100Hz clock
5078 0.5 6+fine level 6 20:39:35 05/08 06:09:23 05/09 open off R5078 0.5disc ortex6 shutteropen sourceoff.png 10Hz
5079 0.36 6+fine level 6 06:47:58 05/09 14:26:08 05/09 open off R5079 0.36disc ortex6 shutteropen sourceoff.png 10Hz
5091 0.36 6+fine level 6 16:25:48 05/09 21:21:11 05/09 close off R5091 0.36disc ortex6 shutterclose sourceoff.png without clock
5092 0.36 6+fine level 6 21:26:23 05/09 06:23:34 05/10 open off R5092 0.36disc ortex6 shutteropen sourceoff.png 10 clock
overlayed plots need to be normalized to the running time! sure Comp newpeak develp.png comparing 4691 (light brown),4690(blue),4687 (red),4676 (green),4685 (purple)


Run List2 GEM,Cathode 2.65,2.95kV

The voltage of the Cathode is 2.95 kV and of the GEMs is 2.65 kV.


Run # discrimination level ortec 474 amplification Attenuation (dB) Start Date End Date Shutter Position Source pulse snapshot picture and Comparison notes
5061 0.40 6 level 6 6 12:15:47 05/04 18:16:57 05/04 close off 10Hz R5061 0.4disc ortex6 6 shutterclose sourceoff.png
5062 0.40 6 level 6 6 18:23:41 05/04 16:12:20 05/05 open off 10Hz R5062 0.4disc ortex6 6 shutteropen sourceoff.png
5063 0.40 6 level 6 8 16:18:02 05/05 22:55:20 05/05 open off 10Hz R5063 0.4disc ortex6 8 shutteropen sourceoff.png
5064 0.40 6 level 6 8 22:59:02 05/05 07:32:26 05/06 open on 10Hz R5064 0.4disc ortex6 8 shutteropen sourceon.png
5065 0.40 6 level 6 8 07:37:17 05/06 12:39:17 05/06 close on 10Hz R5065 0.4disc ortex6 6 shutterclose sourceon.png
5066 0.40 6 level 6 8 02:43:55 05/06 17:44:20 05/06 close off 10Hz R5066 0.4disc ortex6 6 shutterclose sourceoff.png
5198 0.96 6 level 6 8 18:12:00 06/03 00:05:32 06/04 open off 700Hz R5198 0.96disc ortex6 6 shutteropen sourceoff.png
5200 0.96 6 level 6 8 00:08:49 06/04 07:19:28 06/04 close off 10Hz R5200 0.96disc ortex6 6 shutterclose sourceoff.png
5204 0.96 6 level 6 8 09:33:45 06/04 14:31:49 06/04 open off 10Hz R5204 0.96disc ortex6 6 shutteropen sourceoff.png
5215 1.55 6 level 6 8 16:04:59 06/04 20:15:59 06/04 close off 10Hz

R5215 1.55disc ortex6 6 shutterclose sourceoff.png

5224 1.25 6 level 6 8 21:45:45 06/04 07:12:49 06/05 open off 10Hz R5224 1.25disc ortex6 6 shutteropen sourceoff.png
5225 0.96 6 level 6 8 7:15:51 06/05 07:12:49 06/04 open off 10Hz R5224 0.96disc ortex6 6 shutteropen sourceoff.png



Run List3 GEM,Cathode 2.7,3kV

Calibration curve

Charge channelnumber x6 6 attenuated.png


,Measurements


The voltage of the Cathode is 3 kV and of the GEMs is 2.7 kV. Without any attenuation -85 mV was the initial voltage and its equivalent charge is 1.02 nC. According this value the charge below is calculated using

[math] Q = Q_0 10^{(L_v/20)} [/math]

Run # discrimination level ortec 474 amplification Attenuation (dB) Start Date End Date Shutter Position Source pulse snapshot picture and Comparison notes Channel number ADC charge (nC) Detector charge (nC)
5072 0.50 6 level 6 11 18:20:09 05/06 22:28:25 05/04 open off 10Hz R5072 0.5disc ortex6 6 shutteropen sourceoff.png 1650 , 3500 0.766, 1.506 7.7, 15.06
5073 0.50 6 level 6 11 22:31:50 05/06 06:09:58 05/07 open on 10Hz R5073 0.5disc ortex6 6 shutteropen sourceon.png
5074 0.50 6 level 6 11 06:16:00 05/07 12:39:58 05/07 close on 10Hz R5074 0.5disc ortex6 6 shutterclose sourceon.png
5075 0.50 6 level 6 11 12:45:04 05/07 07:58:00 05/08 close off 10Hz R5075 0.5disc ortex6 6 shutterclose sourceoffS.png
5076 0.50 6 level 6 11 08:00:44 05/08 13:06:40 05/08 open off 10Hz R5076 0.5disc ortex6 6 shutteropen sourceoff.png
5077 0.50 6 level 6 11 13:09:56 05/08 20:27:39 05/08 close off 10Hz R5077 0.5disc ortex6 6 shutterclose sourceoff.png





Run List 4 GEM,Cathode 2.75,3.05kV

Run # discrimination level ortec 474 amplification Attenuation (dB) Start Date End Date Shutter Position Source pulse snapshot picture and Comparison notes Channel number ADC charge (nC) Detector charge (nC)
5228 1.29 6 level 6 15 10:26:45 06/05 14:48:25 06/05 open off 10Hz R5228 15att ortex6 6 shutteropen sourceoff.png
5229 1.29 6 level 6 15 14:49:16 06/05 20:27:39 05/08 close off 10Hz 90px




histogram analysis Shutter Open - Closed

GEM detector voltage settings:

Discriminator:

Amplification:

Shutter open run 4676 took data for 44480 seconds (12.4 hrs) and Shutter closed run 4675 took data for 28638 seconds (8 hrs)

R4676 raw.png R4675 raw.png
Run 4676 :raw shutter Open ADC spectrum Run 4675 raw shutter closed ADC spectrum
R4676 norm.png R4675 norm.png
Run 4676 :NORMALIZED shutter Open ADC spectrum Run 4675 NORMALIZED shutter closed ADC spectrum


Assume that the single peak for the Closed shutter spectrum is the result of less charge being liberated by the right most peak of the shutter open spectrum due to the energy lost by the ionizing particle as it travels through the 1mm thick FR4 shutter into the ionization chamber.

R4676-4675 Ovrlay.png R4675-4675 ShiftedOverlay raw.png
Run 4676 :raw shutter Open ADC spectrum Run 4675 raw shutter closed ADC spectrum
R4676-4675.png
Shutter Open - Shutter Closed Difference

U-233 fission x-section data

U-233 fissionxsection 0.01-100MeV.gif


U-233 fissionxsection fullenergyrange.gif

What is the energy distribution of Beta and Photon from U-233

Gamma distribution for U-233 and its daughters are in metioned in details in the documents , File:U233 day gamma.pdf <ref>http://www.radiochemistry.org/periodictable/gamma_spectra , Wed. 04/10/2013</ref>

The energy range of the emitted gamma is shown in the following table .

nuclide Energy Minimum Energy Maximum (keV)
U-233 25 1,119
Ra-225 40 40
Ac-225 10.5 758.9
Fr-221 96.8 410.7
At-217 140 593.1
Bi-213 323.81 1,119.4


Negative beta particles are emitted mainly from U-233 daughters as shown in the figure <ref> http://itu.jrc.ec.europa.eu/index.php?id=204, Wed. 04/10/2013 </ref>

U-233 decay beta energy.jpg


The following table shows the negative beta emitter nuclides,their parent nuclides, and their half lives:

Nuclides energy (MeV) half life
[math]Ra^{225} \rightarrow Ac^{225}[/math] 0.357 14d.
[math]Bi^{213} \rightarrow Po^{213}[/math] 1.426 46min.
[math]Tl^{209} \rightarrow Pb^{209}[/math] 1.981 2.2 min.
[math]Pb^{209} \rightarrow Bi^{209}[/math] 0.644 3.25h
[math]Bi^{209}[/math] 1.893 stable

What is the energy distribution after the 1 mm FR4 shutter

electrons

The energy distribution below represents the incidence electron on a 1 mm FR4 shutter.

E spectrum.png


The energy distribution of photons was observed on the opposite side of the shutter

Photon spectrum.png


Electrons (with least energy from U-233= 0.2 MeV) pass through the shutter have the energy distribution below.

photons

Number of ions produced from Beta and Photon in ArCo2

EMTest10 is used to calculate the average number of ions (electrons) when a 101 beta of 1 MeV are fired in a world that contains ArCO2. (13.5 per primary electron).


SecondaryElectron Energy 1Mevbeta.png

Calibrating GEM detector

The charge of the detector detected by the trigger output, the ADC distributes the charge over 4096 channel (12 bit CAEN V792). The aim is to calibrate the charge collected to the ADC channel number by injecting a known pulse in the wired electronics system used for detecting and processing the detector's charge.The following figure shows the the calibration curve.

V channelnumber.png


C channelnumber.png


Amplifier effect on the signal

Ortec 474 timing filter amplifier amplifies the signal from the trigger output.The amplification will make a shift in the channel number compared to the same signal without application. To determine exactly the shift in channel number after the amplification, a choice for an input signal amplitude to charge the ADC just above noise, then amplifying the same input then recording the channel number (if possible). For example, generating a pulse of 0.1 V amplitude with an offset of 0.06 V using stanford research system pulse generator DG535 will hit channel 291 +_0.34 (run#4829), after the amplification it hits channel number 3767 +_0.78. Input pulse for the attenuator is 1.80V +_ 0.045, and the attenuator output pulse is 222 +_ 2.5 mV (factor of 8.1) when is set on 17.5 dB.

04/26/13


Run Number attenuation (dB) Amplification Average channel Number Average channel Number - Noise (79) calculated gain Notes
4853 0 0 880 801 0 reference for the next two
4854 2 0 553 474 4.6
4855 4 0 304 225 11.0
4860 0 0 3399 3320 0
4861 14 0 98.46 19.46 44.6
4862 0 0 3514 3435 0
4863 14 0 133 54 36.1
4868 0 0 3903 3824 0
4869 14 0 114 35 40.8
4872 0 0 2974 2895 0
4846 24.5 yes 436 357 18.2
4848 18 yes 1720 1641 4.9
4849 20 yes 1213 1134 8.1
4850 14 yes 3210 3131 -0.7
4851 16 yes 2365 2286 2.1


04/27/13

unamplified input pulse passed through an attenuator, the attenuation is changed (without changing the input pulse offset of the input), the results are in the following table:

Run Number attenuation (dB) Average channel Number Average channel Number - Noise (79) calculated gain
4894 0 3653 3574 0
4897 8 1104 1025 10.8
4898 9 916 837 12.6
4899 6 1531 1452 7.8
4898 3 2380 2301 3.8

04/28/13

Amplified x4 level 4 fine gain


Run Number attenuation (dB) Average channel Number Average channel Number - Noise (79) calculated gain
4905 0 3779 3700 0
4906 3 2580 2501 3.4
4907 6 1776 1679 6.8
4908 9 1124 1045 10.9
4909 12 626 547 16.6
4910 15 287 208 25
4911 18 99 20 42.6


05/04/13

Amplified x6 level 6 fine gain


Charge channelnumber x6 6.png


With attenuator

Charge channelnumber x6 6 attenuated.png

Mathmatica x6 6 attenuated.png


According to the calibration curve above the charge collected by the ADC is determined in the table above.[https://wiki.iac.isu.edu/index.php/Neutron_TGEM_Detector_Abdel#Run_List3 ]

05/10/13 & 06/03/13

The table below shows the measurements of the charge of a square pulse that has an amplitude of -0.49 V (osc. 0.504+_ 0 V )with a zero offset and a width of 25.2us. The gate width is 70ns.

[math] Q = Q_0 10^{(L_v/20)} [/math]

Run Number attenuation (dB) Average channel Number Pedestal subtracted Average channel Number calculated gain
5120 0 3876.27 3797 0
5120 3 3057 2977
5123 6 1906 1827
5124 9 1339 1260
5125 12 940 861
5126 14 742 663
data2 06/03/13
5172 0 3818.94 +/- 0.06
5173 3 2685.03 +/- 0.05
5174 6 1889.48 +/- 0.05
5176 9 1322.00 +/- 0.03
5177 12 926.62 +/- 0.03
5178 15 647.03 +/- 0.02


Amplifier

An amplifier (x6 level 6) was added to amplify the signal before attenuation, a square pulse of an amplitude of (1st time-0.18V) and for (the second time 0.47V) (osc. 235 +_ 4 mV) with a zero offset and a width of 25.8us was used, the gate width was 70ns. After the amplification the signal amplitude is (first time 3.42+_ 0.29 V) (2nd time: gate integrate 4.21 +/-0 V).

[math] Q = Q_0 10^{(L_v/20)} [/math]


Run Number attenuation (dB) Average channel Number Average channel Number - Noise (79) charge collected (nC) calculated attenuation expected attenuation V(mV)
5134 14 3952 3873 1.6552 0 647+_32
5135 15 3503 3424 1.4756 0.997 576+_27
5136 18 2474 2395 1.064 20*log(3952/2472) = 4.2 4 416+_16
5137 21 1752 1673 0.7752 6.589 235+_ 32
5138 24 1206 1127 0.5568 20*log(3873/1127) = 10.7 10 222 +_7
Data2 06/03/13 Pedestal 63
5180 14 2872.76 +/- 0.09 872
5181 15 2477.22 +/- 0.08 782
5182 18 1823.29 +/- 0.08 546
5183 21 1306.90 +/- 0.04 392
5184 24 933.94 +/- 0.03 271

05/24/13

ADC calibration using a battery

Using a 1.5V battery connected to to 5 kohm resistor, then 25 ohm terminated ADC. The oscilloscope measures 15 mV DC voltage for the battery as it is 50 ohm terminated.


Run Number channel Number Channel Number - padestal Gate width (ns) Charge (nC)
62 851 771 500 0.015*(Gate width)/25 = 0.3
63 1263 1184 750 0.45
64 1702 1623 1000 0.6
65 1250 2072 2151 0.75
66 2500 3897 3976 1.5


Batttery cal.png

05/30/13

ADC calibration using a battery

Using a 1.5V battery with a grounded positive terminal connected to to 5 kohm resistor, then 50 ohm terminated ADC. The oscilloscope measured 14.4 mV DC voltage of the battery when it is 50 ohm terminated.


Run Number channel Number +_ error Gate width (ns) charge (nC)
97 865 +_ 0.04 500 =0.0144*(Gate width=500)/50=0.144
98 493+_0.03 250 0.072
101 1283 +_0.03 750 0.216
102 1000
104 2105 +_ 0.04 1250 0.36
106 3317 +_ 0.02 2000 0.576
107 overcharge 2500


Battery grounded cal.png


Measurements Notes

1- The slope of the calibration curve as the ADC is connected to the battery with the positive terminal grounded is 178 pC.

2- The ADC manual manual mentioned 100pC gain/count, does count = channel? Also it is measures max. tolerate voltage >25 mV with +_ 2 mV as maximum voltage offset, the battery provides 14.4 mV offset, Does the ADC measure that the battery voltage or consider it more that the offset limit and measure only within the offset limit?


Today 05/31 the equipment moved to the LDS to start our measurements but I am still thinking how to improve our calibration curve measurements to get the right slope.


6/2/13

Measuring the grounded positive terminal battery output again in the LDS, V= 14.7 mV measured by the oscilloscope. (R= 5kohm, V=1.5, I= 1.5/5kohm = 0.3 mA, oscilloscope channel 2 is 46 ohm terminated, then V = 46*0.3mA = 13.8 mV). The ADC noise level in channel 5 (signal channel) is 63 (run #5162) which is 42.1 ohm terminated.


Run Number channel Number +_ error channel Number - Pedestal Gate width width (ns) charge (pC)
5161 356.14 +/- 0.01 293 178 = 14.7*(Gate width)/42.1 = 62.2
5163 712.09 [math]\pm[/math] 0.02 649 398 139.0
5164 1368.60 +_ 0.02 1305 798 278.6
5165 2662.70 +_ 0.02 2600 1592 555.9
5157 3670 +_ 0.01 3607 2216 773.8


Battery grounded cal2.png


06/04/13

Amplified x6 level 6 fine gain

stanford pulse generator is used as source for a negative pulse of width of 11.8us +/- 3, and the gate width is 32.94 ns +/- 0.02 . all the voltage measurement is recorded by using oscilloscope 46 ohm terminated. So the amplifier input current is (input signal amplitude/46)


Run Number Average channel Number Average channel Number - Noise (63) amplified pulse amp. (mV) +/- SD input signal (mV) Charge (pC)
5205 2415.57 +/- 0.13 2352.57 945 +/- 8 51 +/- 1 676.702
5207 2644.05+/- 0.10 2581.05 1040 +/- 8 56 +/- 1 744.730
5208 2840.40+/- 0.15 2777.40 1130 +/- 10 60 +/- 1 809.178
5209 3066.89+/- 0.18 3003.89 1200 +/- 8 65 +/- 1 859.304
5210 3293.51+/- 0.21 3230.51 1280 +/- 8 70 +/- 1 916.591
5214 3744.33+/- 0.15 3681.33 1460 +/- 8 80 +/- 1 1045.49

Charge cal1 ampx6 level6.png

Time to observe the GEM signal

In the case of triple GEM detector with a gas flow of 0.3 SCFH and 2650V and 2950V on GEM cards and cathode successively, a signal lower than the noise (of 16 mV and amplified twice) is observed at 770.0s +/- 0.1.

The normal rate (8 MHz +/- 2 as measured by the oscilloscope) is observed after 952.9s +/- 0.1.

THGEM card tasks and tests

New THGEM cards

Two new fully machined cards are going to be tested in air and ArCH4, if they passes 2000 V potential bwtween the top and the bottom, then they are going to be installed in ArCh4 gas chamber.

The older THGEM cards will have a high voltage enough to have one spark/min to clean impurities or surface defects.

References

THGEM design

THGEM#9

Media:Shalem_MSthesis_march2005.pdf


Media:Raz_Alon_MSthesis_Dec2007.pdf

Electric field Simulation

Rim size dependence

File:THGEM Efield simulation.pdf


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


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[1]


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[2]

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)[3]

Stainless Steel deflection [4]

Data Sheets

radioactive surface cleaner NoCount MDSD File:Radioactive surface cleaner.pdf.

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


[[5]]

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


[6]

[7]

IAEA Photonuclear Data Library [8]
Data Acquisition

Warren_logbook[9]


Warren_Thesis [10]

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:

Hexagonal representaion holes 04mm 1mmc2c.jpg


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

Holes covered by mask.jpeg

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


http://134.50.203.63/


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