Neutron TGEM Detector Abdel

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File:Measurements 1.pdf File:Measurements 2.pdf File:Measurements 3.pdf



alpha calibration

Ch alphaE.png

File:Raw data all.pdf

The main peaks are for the following channel numbers,

You need to redo these plots in publication quality with proper axis labels containing units.

Ch alphap1.png Ch alphap2.png

channel Number Energy Upper limit (MeV) Energy lower limit (MeV) average energy (MeV) Notes
4828 4.90 4.79 4.85 +_ 0.02
4869 4.94 4.83 4.88 +_ 0.02

Gamma Spectrum for U-233

Gamma spect.png

Last runs

Run Number start end Time (min) Shutter Source Count rate (counts/min) Notes
9005 05/15 15:00 05/16 10:55 open off 50
9006 05/16 10:57 05/17 22:18 open on 48
9007 05/17 22:23 05/18 19:20 closed on 30
9008 05/18 21:46 05/19 19:59 closed off 30 high beta effect
9010 05/21 23:23 05/22 10:00 closed off 30 high beta effect
9023 05/26 13:06 05/26 13:17 11 open off 87 GEM2.9kV 3.6kV
9024 05/26 13:20 05/26 13:27 7 closed off 26 GEM2.8kV 3.5kV (beta effect decreased)
9032 06/13 12:35 06/13 12:45 10 open off 87 GEM2.8kV 3.5kV (ISU power shutdown)
9033 06/13 12:35 06/13 12:45 10 closed off 26 GEM2.8kV 3.5kV
9034 06/15 20:55 06/15 21:05 10 open off 45 GEM2.8kV 3.5kV
9035 06/15 21:06 06/13 21:16 10 closed off 27 GEM2.8kV 3.5kV
9036 06/17 14:48 06/17 14:58 10 closed off 28 GEM2.8kV 3.5kV
9037 06/17 14:59 06/17 14:09 10 open off 28 GEM2.8kV 3.5kV

The charge spectrum returned to were it was before the neutron exposure after 29 days for closed shutter.


Peak sensing gate

GEM PS gate.png

QDC gate

GEM QDC gate.png

TDC start

TDC pulser.png



QDC shows a difference

QDC source on off 7724 7726.png

Measurements of the frequently used gas mixture 90/10 Ar/CO2 for the second peak

Changes from the former set up
  1. Using the eG&G timing filter amp. 474 instead of the spectroscopic amp. to amplify the input for the peak sensing ADC.
  2. Gate of a width of 4us has been delyed to track the second peak, as a result part of output spectrum is lost except for the delayed part within the gate width as shown in the figures below:

PS l1.png


PS d1.pngPS d2.png

Run Number Date start end Time (min) Shutter Source Count rate (counts/min) Notes
7435 08/24/14 19:30:48 19:55:32 open on 400 a peak is noticed on channel 400
7436 08/24/14 19:59:05 20:40:11 open off 216 the peak disappeared
7438 08/24/14 19:59:05 10:00:00 open on 0.0146 triple coin., high noise, max. is ch 355
7444 08/25/14 21:17:25 21:20:35 open on 230 gate delay 700 ns, peak disappeared Gate delay700ns.png
7446 08/25/14 21:29:51 21:38:55 open off 185 does not count for P_B. peak disappeared

Shutteropen sourceon off.png

unknown gas mixed bottle measurements


Changing the leading edge disc. to understand the Peak sensing and explain the cut int he peak sensing graph.

Measuring the noise. by starting by low signal rate to distinguish the signal from the noise.

Channels and signals

device ch input source
ADC 5 GEM's trigout
Peak sensing 7 15 GEM's trigout
Peak sensing 5 11 PMT Left
Peak sensing 8 17 PMT right
PS translator
TDC 27 GEM's trigout
TDC 31 (Stopper) triple coincidence (OR Mode)
TDC B2 18 GEM's trigout multi-hit
TDC B6 22 GEM's B_p
TDC 6 30 (pulser) triple coincidence (OR Mode)
TDC 7 23 delayed GEM's trigout

Run Number Date start end Time (min) Shutter Source Count rate (counts/min) Notes
7273 08/06/14 07:10:38 11:41:00 12502 open off 67 0.1 flow rate
7274 08/06/14 11:49:35 18:15:01 23126 closed off 39 0.1 flow rate
7275 08/06/14 20:37:07 09:10:10 closed off 40 0.2 flow rate
7276 08/06/14 09:15:00 09:32:00 open off 80 0.2 flow rate amplification increases from 50 to 100
7277 08/06/14 09:33:08 11:40:42 7654 open off 81 0.2
7295 08/08/14 17:36:58 19:55:59 4741 closed off 60 0.2
7296 08/08/14 22:28:01 23:43:14 closed off 58 0.3
7297 08/08/14 23:48:14 12:08:00 37186 open off 93 0.3
7298 08/09/14 00:16:14 06:08:03 21109 closed off 56 0.3
7299 08/10/14 19:27:12 20:09:04 2152 closed on 107 0.1
7300 08/10/14 20:11:30 20:46:29 2099 open on 136 0.1
7302 08/11/14 06:53:14 07:22:45 1771 closed on 114 0.2
7303 08/11/14 07:26:58 07:48:01 1263 open on 167 0.2
7305 08/11/14 13:21:16 13:55:05 2029 open on 178 0.3
7306 08/11/14 14:41:00 15:40:00 3540 closed on 110 0.3
7307 08/14/14 08:14:15 08:20:39 384 closed off 0.1 noise measurements (pulser only)
7308 08/14/14 08:22:43 08:29:23 open off 1314 0.1 noise measurements (pulser only) same noise level as shutter closed (ch. 86) for Peak sensing ADC
7309 08/14/14 08:35:09 09:45:37 4229 open off 0.1 flow rate was not exact, little less.
7310 08/14/14 09:46:12 11:18:39 5547 open off 54 0.1 flow rate was not exact, little less.
7311 08/14/14 11:19:45 13:01:57 6132 open off 52 0.1 flow rate was not exact, little less.
7312 08/14/14 13:10:50 14:28:07 4637 open off 72 0.1 flow rate was not exact, little less.
7313 08/14/14 14:30:24 15:38: 48 4056 open off 80 0.1 flow rate as is used to be
7314 08/14/14 15:41: 52 16:46:55 3897 open on 147 0.1 flow rate as is used to be
7315 08/14/14 16:49: 59 19:14:30 8729 open on 148 0.1 flow rate as is used to be
7316 08/14/14 19:18:43 22:14:07 10596 open on 147 0.1 flow rate as is used to be
7317 08/14/14 22:18:24 10:18:52 43220 open on 0.0095 0.1 flow rate, triple coincidence
7318 08/15/14 10:24:00 12:42:23 8303 open on 147 0.1 flow rate
7319 08/15/14 12:46:14 15:46:09 10795 open on 148 0.1 flow rate
7323 08/15-16/14 16:59:39 06:03:11 46970 open off 0.0011 0.1 flow rate, triple coincidence
7329 08/16/14 07:06:32 10:35:35 12543 open off 83 0.1 flow rate, PMT's charge is measured for L and R
7330 08/16/14 10:41:58 12:48:33 7595 open on 146 0.1 flow rate
7331 08/16-17/14 12:52:07 06:45:03 64384 open off 0.0016 0.1 flow rate, triple coincidence, coda counted 111 but the data file is empty!
7332 08/17/14 06:52:26 07:04:45 739 open on 1367 0.1 flow rate noise measurements with the wave generator
7333 08/17/14 07:05:50 08:53:54 open on 155 0.1 flow rate
7334 08/17/14 08:57:02 13:13:38 open off 82 0.1 flow rate
7337 08/17/14 14:17:24 14:30:29 open on 1400 0.1 flow rate, GEM 2.92 kV , CATH 3.47kV(+50V), noise measurements with the wave generator
7338 08/17/14 14:31:37 16:17:45 open on 163 0.1 flow rate
7339 08/17/14 16:20:25 16:35:45 open off 1368 0.1 flow rate, noise measurements with the wave generator
7340 08/17/14 16:37:01 20:33:04 open off 95 0.1 flow rate
7341 08/17-18/14 20:40:16 06:18:43 open off 0.0015 0.1 flow rate, triple coincidence
7342 08/18/14 06:25:44 06:37:43 open on 1403 0.1 flow rate, noise measurements
7345 08/18/14 06:39:23 14:17:58 open on 0.0128 0.1 flow rate, triple coincidence
7355 08/18/14 16:03:29 19:59:51 open off 75 0.1 flow rate, EM 2.82 kV , CATH 3.37kV(-50V), CAEN translator is used
7356 08/18/14 20:03:05 20:07:58 open on 2k 0.1 flow rate, noise measurement
7357 08/18/14 20:08:43 22:48:22 open on 142 0.1 flow rate
7358 08/18-19/14 22:53:13 10:52:44 open on 0.0082 0.1 flow rate , triple coincidence
7359 08/19/14 10:55:49 10:59:52 open on 2.1k 0.1 flow rate , noise measurement
7360 08/19/14 11:00:38 14:26:38 open on 156 0.1 flow rate noise measurement with 1 Hz sampling
7361 08/19/14 14:40:49 18:25:00 open on 0 0.1 flow rate with 1 Hz sampling (AND gate)
7362 08/19/14 18:33:15 18:38:54 open on 1.5k 0.1 flow rate triple coinc.(OR)
7363 08/19-20/14 18:39:46 13:39:45 open on 0.0081 0.1 flow rate triple coinc.(OR)
7364 08/20/14 13:44:56 13:50:57 open off 1.55k 0.1 flow rate noise measurements, 2.87, 3.42kV for GEM and CATH
7367 08/20/14 15:08:27 16:49:37 open off 86 0.1 flow rate, 2.87, 3.42kV for GEM and CATH
7368 08/20/14 16:53:42 17:15:49 open on 154 0.1 flow rate
7369 08/20/14 17:17:39 20:28:43 open off 86 0.1 flow rate, spec. amplifier decreased from 100 to 50
7479 08/27/14 10:02:21 10:42:09 open on 64 0.1 flow rate,
7480 08/27/14 10:46:18 14:17:22 open off 11 0.1 flow rate,
7481 08/27/14 14:19:33 14:43:39 close on 78 0.1 flow rate,
7488 08/27/14 16:16:37 16:48:53 open on 86 0.1 flow rate,
7491 08/27/14 18:09:27 18:59:05 open on 86 0.1 flow rate,

Peak sensing measurements by 08/28/14

Peak sensning measurements for GEM were recorded in the time between 8:00 am to 9:44am for shutter open as the following

Source On Source Off
7507 7506
7509 7508
7511 7510
7513 7512
7515 7514
7517 7516
7519 7518
7521 7520

Unknownbootle measurements 06 13.pngUnknownbootle measurements 14 21.png

Different output for each run when Peak sensing is used to measure the charge, what is noticed that the charge is different from one run to another, but all the runs show that the amount of charge collected is bigger when the shutter is open with the source on it except for run 7511. By comparing all the runs, As the shutter is open, the maximum charge is collected by channel number 800, as the source is on the detector, the collected charge reached up to channel 1000 at most.

Measuring the data started by 8 am, the noise rate increased so it increased the event rate from 30s to 80s event/s, and it did not decrease until now (Thur. 15:36 08/28/14). all module wiring were checked but without any result. I am using the 90/10 Ar/CO2 bottle as hope to take some measurements but when the noise level goes down maybe this evening to repeat the same measuremnts.

The following reference shows a change in collected charge as the tenperature changes <ref>"Discrimination of nuclear recoils from alpha particles with superheated liquids" F Aubin et al 2008 New J. Phys. 10 103017 </ref>

Temp signal effect.jpg

Flow rate and figures

03 flow rate

03 sourceOn.png 03 sourceoff.png 03 openOn off sub.png

02 flow rate

02 sourceOn.png 02 sourceoff.png 02 openOn off sub.png

01 flow rate

01 sourceOn.png 01 sourceoff.png

Common Start Common Stop exchange

Edit the file

cd /usr/local/coda/2.5/readoutlist/v1495trigPAT/

as the following:

for common start comment:

/* c775CommonStop(TDC_ID);

for common stop uncomment:


Ionization xsections for different particles emitted from U-233


Photoabosorption Ar.png Photoabosorption CO2.png Photoabosorption Ar CO2.png

Ref. :


Electron ion Ar.png

Ref. :

Data Nucl. Data Tables 54 (1993) 75 File:Electron ionization Ar.pdf

Alpha Particles

Alpha ionization.png

Ref. :

Data Nucl. Data Tables 54 (1993) 75

Coincidence Measurements for GEM and the Plastic scintillator

Coincidence Measurement for the scintillator PMT's without shielding and without source
Date Time No. of Counts (counts) Count rate (counts/min)
07/09/14 1066 659005 618
07/10/14 538 368974 686

Triple coincidence Measurement for the scintillator PMT's shielded and without source

Triple coincidence among the 2 PMT's and the GEM detector is measured using coincidence module caberra 2144 and ortec 778 counter, count rate is 0.3+_ 0.03 Hz. However, the rate was zero before shielding.

The following pics show The GEM output with triple coincidence signal, it is observed that different GEM peaks coincide with the triple signal, which shows that adding the shielding contaminates the neutron signal.

GEM triple smallpeak.png GEM triple bigpeak.png GEM triple twopeaks.png

Coincidence Measurements for the Plastic scintillator after shielding

Without source

The plastic scintillator count rate before shielding and without source was in average 12 +_ 1 Hz, lead is added to the GEM and to the plastic scintillator which did not change the rate of the coincidence for the plastic scintillator . Neither closing the box door with lead nor adding lead to the top of the box did make any change in the number of counts for the plastic scintillator.

With a source

Background count rate

Date Time PSD_e (counts) PSD_e (counts/min) LED (low disctrinimation)(counts) LED (low disctrinimation)(counts/min) LED (high disctrinimation) (counts) LED (high disctrinimation) (counts/min)
07/01/14 1166 56671 49 2936748 2519 10 0.009
07/01/14 231 10529 572657 1542

data graphs


B pdaily counts.png

The above graph represents the change in the count rate of B_p, as the shutter is open (green) and as it is closed (red), the error bars get smaller since each point represents the average of two sets of daily measurements, in addition to, changing the PS discriminator's level after the second measurement.


S pdaily counts.png

The above graph has the same legend as the one for B_p, error bars increase for some data when the shutter is open, since one or more of the daily measurements has a higher number of counts because of U-233(4)'s spentaneous fission. (the number of counts is close to the number of counts as the shutter is open and the source is on).

Small=[math]S_{PSD} - S_{PSDE}[/math]

Testing GEM Experiment test 10/23/13

The GEM detector was tested for signal and discharge as the voltage of the cathode and HV-circuit divider is 3.3 kV and 2.7 kV successively.

The GEM detector signal is observed as it used to work before. the pictures below show the signal detected as the shutter is open and as it is close.

shutter close GEM close 1.png GEM close 2.png
shutter open GEM open 1.png GEM open 2.png GEM open 3.png GEM open 4.png

THGEM#9 Counting Experiment test 1/4/13

THGEM#9 Counting Experiment

GEM HV-divider circuit

GEM HV-divider circuit in shown in the figure, measurements were recorded for for top and bottom voltage of each preamplifier.

GEM HV Dist Net.jpg

The table below shows value of the voltage on each preamplifier's side relative to ground.

[math] V_{source} \pm 1 [/math] [math] V_{G1T} \pm 1 [/math] [math] V_{G1B} \pm 1 [/math] [math] \Delta V_1 \pm 1 [/math] [math] V_{G2T} \pm 1 [/math] [math] V_{G2B} \pm 1 [/math] [math] \Delta V_2 \pm 1[/math] [math] V_{G3T} \pm 1 [/math] [math] V_{G3B} \pm 1 [/math] [math] \Delta V_3 \pm 1 [/math]
2550 2579 2259 304 1671 1394 279 818 570 245
2600 2630 2303 310 1704 1421 285 834 581 250
2650 2680 2348 316 1737 1449 290 850 592 255
2700 2731 2393 322 1770 1476 296 866 603 260
2750 2781 2373 328 1803 1503 302 882 614 264
2800 2832 2482 332 1836 1530 307 898 625 269

The source voltage means the voltage value on the 4-channel CAEN N470 display. (suppose to be equal to the voltage of the top GEM1).

the values are going to be an input for ANSYS which is going to simulate the electric field for each source voltage separately, ANSYS' output files will be an input for Garfield to simulate the electron multiplication by the triple GEM.

GEM alpha-Beta detector counter

GEM Alpha-Beta detector counter

GEM gain data graphs and GEM Calibration in LDS

GEM Detector

GEM performance QDC data graphs

Calibrating GEM detector

Electronics Flow Chart

LDS electronics flow chart.png

GEM Detector and Scintillator

GEM and Sci. data and measuurements

GEM gain data graphs and GEM Calibration at the IAC

Haitham may only alter the QDC's dual timer and a CFD for the QDC in the IAC DAQ.
Haitham may only add signals to the NIM->ECL translator
Haitham is not allowed to change any cables that are used for the PAA setup

The detector is installed in the IAC after modifications took place in the detector design.

These modifications are:

1- The detector kipton window's area increased to the same size of the GEM cards( 10X10 cm)

2- The distance of the cathode from the first GEM increased up to 1.2 cm. previously the distance was about 3.5 mm. (No change in GEM's distances 2.8mm, or the readout 0.5 mm)

Increasing the drift distance demands an increase in cathode potential to maintain the same values of the electric field in the old setup.

3- The detector is installed in a wooden box, in addition to a plastic scintillator which was placed to cover part of the detector window.

GEM performance data graphs

Electronics Flow Chart

IAC electronics flow chart.png


U-233 fission x-section data and fission yield

U-233 fissionxsection 0.01-100MeV.gif U-233 fissionxsection fullenergyrange.gif

U-233 fissionxyield percent.png

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


nuclide Energy (MeV)
Pb-213 8.4
Bi-213 5.9
At-217 6.3
Fr-221 6.3
Th-229 4.85 (alpha spectrum, highest counts for is 4.85 MeV)


Gamma distribution for U-233 and its daughters are in metioned in details in the documents , File:U233 day gamma.pdf <ref> , 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


Beta particles are emitted mainly from U-233 daughters as shown in the figure <ref>, Wed. 04/10/2013 </ref>

U-233 decay beta energy.jpg

U-233 -> Th-229, emitted alpha particles have energy of 4.8 MeV.

Insert energy distribution for Betas

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

electron shutter penetration

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

E spectrum.png

graph of electron energy for electron penetrating shutter (did any not penetrate?, how many?)

photons below were produced by above incident electron?

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.

alpha shutter penetration


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

The needed 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.

GEM Signal after the latest modification on the fission chamber 07/01/13

The signal of the detector is observed as the shutter is open and close.

shutter close GEM close.jpg GEM close1.jpg GEM close2.jpg GEM open.jpg
shutter open GEM open 7 1.jpg

GEM's signal testing when it a long cable is used

The GEM signal is tested when a long cable is used to transfer the signal to the oscilloscope as the shutter is open, and without the cable. Oscilloscope pictures shows an attenuation to the signal up to 30%.

Long bnc cable GEM longcable1.jpg GEM longcable2.jpg
Short bnc cable GEM shortcable.jpg

Roy's detector infomation and measurements

U-233 metal deposited source is measured by Protean Instrument corporation gaseous detector, has a model number of WPC9450 (serial number: 0915723)and uses (P10) gas mixture, as shown below:

Shutter position Alpha particles /min. Beta particles /min.
Open 6879 900
Close 1 38

The source was in a plate of a diameter of 16 cm which was exposed to to the sensitive part of the detector of a height of 2-3 mm.

The activity of the source is calculated based on the solid angle [math] \frac {A \times W}{4\pi} [/math]

where A is the count per second and W is the detector solid angle.

For the previous measurement, the solid angle is almost [math]2\pi [/math], so the the actvity of the source is twice the measured value in count/second.

IAC experiment producing neutrons

One of the IAC experiments produces neutrons, the neutron spectrum from Tungsten target is simulated outside and inside water (moderator) as shown in the figure below

Moderator nspect.png

In the simulation above , They are interested in close distances to the Tungsten target inside the water container, it is 1 ft cubed container and is made of aluminium and covered polyester.

Exp setup.png


THGEM design




Electric field Simulation

Rim size dependence

File:THGEM Efield simulation.pdf

2010 THGEM design(s)

File:THGEM 2009 design gas efficiency.pdf


Voss and 3 russian references for Dy(n,x) cross sections Dy photon gammas spectrum


File:NIM A590 2008 pg134 Eberhardt.pdf Prep Targets

Neutron cross sections for different elements Media:Neutron_cross_sections.pdf

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: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. rp097mono HV divier.pdf

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


Resistors online store :






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

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


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

Machining Uranium

Uranium will ignite in powder form

coating Uranium


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.



IAEA Photonuclear Data Library [8]
Data Acquisition


Warren_Thesis [10]

Related To Gaseous Detectors

Breakdown and Detector Failure (10/21/10)

Different kind of micro-pattern detectors


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


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.

Resistive glue to compare

File:Duralco 4461.pdf

b.) mix with a metal similar to Th-232.

c.) construct bed of 0.4 mm nails. Look for 0.4 mm diameter pins.


New vendor for carbon paste.

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



Performance of THGEM as a Neutron Detector



Thick Film Screen Printers


tektronix oscilloscope