Neutron TGEM Detector Abdel

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:

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:

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:

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

With a source

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

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
4663	1.1	4	10:00 04/05	13:14 04/05	open	off
4664	0.9	4	13:14 04/05	16:48 04/05	open	off
4665	0.9	4	17:11 04/05	20:21 04/05	open	on
4666	1.1	4	20:26 04/05	21:38 04/05	open	On
4668	0.25	6	21:47 04/05	7:45 04/06	open	off	compare ampx4 (blue) and ampx6 (red) 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
4676	0.25	6+fine level 4.5	21:06:07 04/06	09:27:29 04/07	open	Off	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	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
4679	0.25	6+fine level 4.5	10:39:19 04/08	22:22:21 04/08	close	off
4680	0.25	6+fine level 4.5	22:26:10 04/08	10:05:07 04/09	open	off
4681	0.25	6+fine level 4.5	10:08:59 04/09	14:26:12 04/09	open	on
4682	0.25	6+fine level 4.5	14:30:43 04/09	06:51:39 04/10	open	off
4683	0.25	6+fine level 4.5	06:56:00 04/10	16:07:36 04/10	close	off	compare r4683 (red) and r4679 (blue) as both have hsutter is close without source
4684	0.25	6+fine level 4.5	16:10:59 04/10	10:46:10 04/11	close	off	compare r4684 (red) and r4683 (blue) as both have hsutter is close without source
4685	0.25	6+fine level 4.5	10:50:52 04/11	07:06:55 04/12	open	off	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	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
4688	0.25	6+fine level 4.5	07:01:35 04/13	10:31:31 04/13	open	off
4689	0.25	6+fine level 4.5	10:33:13 04/13	19:09:56 04/13	close	off	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
4691	0.25	6+fine level 4.5	21:15:44 04/13	09:58:16 04/14	open	off
4692	0.25	6+fine level 4.5	10:05:14 04/15	16:34:50 04/15	open	off	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
4694	0.25	6+fine level 4.5	07:39:30 04/16	14:51:29 04/16	close	off
4694	battery		battery charged collected by the ADC without any electronics used1
4695	battery		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
4917	0.36	6+fine level 4.5	10:00:21 05/01	14:43:05 05/01	open	off
4918	0.36	6+fine level 4.5	14:53:41 05/01	13:56:05 05/01	open	on
4935	0.36	6+fine level 6	16:38:38 05/01	07:30:04 05/02	open	off
4936	0.36	6+fine level 6	07:34:01 05/02	15:02:30 05/02	close	off
4989	0.36	6+fine level 6	11:47:06 05/03	15:40:47 05/03	close	off	10Hz
4990	0.36	6+fine level 6	15:44:10 05/03	22:36:28 05/03	open	off	10Hz
4992	0.36	6+fine level 6	22:57:47 05/03	08:51:26 05/04	close	off	100Hz clock
5078	0.5	6+fine level 6	20:39:35 05/08	06:09:23 05/09	open	off	10Hz
5079	0.36	6+fine level 6	06:47:58 05/09	14:26:08 05/09	open	off	10Hz
5091	0.36	6+fine level 6	16:25:48 05/09	21:21:11 05/09	close	off	without clock
5092	0.36	6+fine level 6	21:26:23 05/09	06:23:34 05/10	open	off	10 clock
overlayed plots need to be normalized to the running time!	sure		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
5062	0.40	6 level 6	6	18:23:41 05/04	16:12:20 05/05	open	off	10Hz
5063	0.40	6 level 6	8	16:18:02 05/05	22:55:20 05/05	open	off	10Hz
5064	0.40	6 level 6	8	22:59:02 05/05	07:32:26 05/06	open	on	10Hz
5065	0.40	6 level 6	8	07:37:17 05/06	12:39:17 05/06	close	on	10Hz
5066	0.40	6 level 6	8	02:43:55 05/06	17:44:20 05/06	close	off	10Hz
5198	0.96	6 level 6	8	18:12:00 06/03	00:05:32 06/04	open	off	700Hz
5200	0.96	6 level 6	8	00:08:49 06/04	07:19:28 06/04	close	off	10Hz
5204	0.96	6 level 6	8	09:33:45 06/04	14:31:49 06/04	open	off	10Hz
5215	1.55	6 level 6	8	16:04:59 06/04	20:15:59 06/04	close	off	10Hz
5224	1.25	6 level 6	8	21:45:45 06/04	07:12:49 06/05	open	off	10Hz
5225	0.96	6 level 6	8	7:15:51 06/05	07:12:49 06/04	open	off	10Hz

Run List3 GEM,Cathode 2.7,3kV

Calibration curve

,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	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
5074	0.50	6 level 6	11	06:16:00 05/07	12:39:58 05/07	close	on	10Hz
5075	0.50	6 level 6	11	12:45:04 05/07	07:58:00 05/08	close	off	10Hz
5076	0.50	6 level 6	11	08:00:44 05/08	13:06:40 05/08	open	off	10Hz
5077	0.50	6 level 6	11	13:09:56 05/08	20:27:39 05/08	close	off	10Hz

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
5229	1.29	6 level 6	15	14:49:16 06/05	19:11:06 06/05	close	off	10Hz
5230	1.29	6 level 6	15	19:12:39 06/05	04:08:00 06/06	open	off	10Hz
5235	1.29	6 level 6	15	04:10:19 06/06	07:35:30 06/06	close	off	10Hz
5236	1.29	6 level 6	15	07:36:39 06/06	10:04:15 06/06	open	off	10Hz
5237	1.29	6 level 6	15	10:06:54 06/06	14:51:54 06/06	close	off	10Hz

Run List 5 GEM,Cathode 2.8,3.10kV

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			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) Run 4676 :raw shutter Open ADC spectrum Run 4675 raw shutter closed ADC spectrum 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. Run 4676 :raw shutter Open ADC spectrum Run 4675 raw shutter closed ADC spectrum Shutter Open - Shutter Closed Difference U-233 fission x-section data 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> 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. The energy distribution of photons was observed on the opposite side of the shutter 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). 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. 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 With attenuator 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 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 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 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 input signal (mV) amplified pulse amp. (mV) +/- SD Charge (pC) Average channel Number Average channel Number - Noise (63) 5205 51 +/- 1 676.702 945 +/- 8 2415.57 +/- 0.13 2352.57 5207 56 +/- 1 744.730 1040 +/- 8 2644.05+/- 0.10 2581.05 5208 60 +/- 1 809.178 1130 +/- 10 2840.40+/- 0.15 2777.40 5209 65 +/- 1 859.304 1200 +/- 8 3066.89+/- 0.18 3003.89 5210 70 +/- 1 916.591 1280 +/- 8 3293.51+/- 0.21 3230.51 5214 80 +/- 1 1045.49 1460 +/- 8 3744.33+/- 0.15 3681.33 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: The mask is made of stainless steel, 10 um laser tolerance with cut the plate to get the shape in the figure: 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/ <references/>