11/01/2015

Measurements

Conclusion

# alpha calibration

The main peaks are for the following channel numbers,

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


 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

# 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.

# QDC TDC PS-ADC setup

Peak sensing gate

QDC gate

TDC start

TDC STOP

QDC shows a difference

# 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:
Lost

Detected

 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 7446 08/25/14 21:29:51 21:38:55 open off 185 does not count for P_B. peak disappeared

# 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 25 PMT L TDC 27 GEM's trigout TDC 29 PMT R TDC 31 (Stopper) triple coincidence (OR Mode) CAEN N638 TDC 17 PMT L TDC B2 18 GEM's trigout multi-hit TDC B6 22 GEM's B_p TDC 21 PMT R 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

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>

03 flow rate

02 flow rate

01 flow rate

# Common Start Common Stop exchange

Edit the file

as the following:

for common start comment:

/* c775CommonStop(TDC_ID);


for common stop uncomment:

 c775CommonStop(TDC_ID);


# Ionization xsections for different particles emitted from U-233

Photons

Electrons

Ref. :

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

Alpha Particles

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.

# 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

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.

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=


# 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 shutter open

# 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.

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

 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 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

Summary

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.

# U-233 fission x-section data and fission yield

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

### Alpha

 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

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

### Beta

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 -> 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 0.357 14d. 1.426 46min. 1.981 2.2 min. 0.644 3.25h 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.

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

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

## 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).

# 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 shutter open

# 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 Short bnc cable

# 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

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

For the previous measurement, the solid angle is almost , 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

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.

# References

THGEM#9

## Electric field Simulation

Rim size dependence

2010 THGEM design(s)
Voss and 3 russian references for Dy(n,x) cross sections


http://arxiv.org/abs/0903.3819 Dy photon gammas spectrum

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

Donald James Hughes, Neutron cross sections, 2nd edition 1958, u.s.a atomic energy commission.Media:Neutron cross sections.pdf

TGEM-2009 File:TGEM 2009.pdf

12 Volt power supply system.

GEANT4_Paticles_Models[2]

Resistors online store : http://www.justradios.com/rescart.html

## RETGEMs

Thick GEM COBRA

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.

## U-238-Xsection and coating references

relative cross section and calibration samples characteristics for a well determined number of fissions per second

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

## Thorium Coating

ThF4 target for sputtering coatings

## Machining Uranium

Uranium will ignite in powder form

coating Uranium

[[5]]

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_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.

Resistive glue to compare

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.

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.

# Vendor

### tektronix oscilloscope

134.50.3.73

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