Difference between revisions of "Neutron TGEM Detector Abdel"

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−
[[2009]]
+
[[HM_2014]]
 +
 
 +
[[2012]]
 +
 
 +
[[2011]]
  
 
[[2010]]
 
[[2010]]
  
−
=AFCRD Reports-2011=
+
[[2009]]
  
−
*A vendor is being sought  for a flex circuit version of the readout card adapter in order to allow the readout cards to attach to the detector more easily.
+
=Dissertation=
−
*A detector gas system upgrade is underway and should be completed before the next quarter
 
−
*A new TGEM card has been machined which was redesigned to reduce spark discharge between two adjacent TGEM preamplifier cards previously observed at 1.7 kV.  The expectation is to reach a TGEM voltage of 2 kV with two preamplifier cards stacked on top of each other and separated by 2.5 mm.
 
  
−
===January===
+
;11/01/2015
  
−
* Determined the closest distance between two TGEM amplifier cards at 2kV to be 2.5 cm.
+
Measurements
−
* Readout card adapters have arrived
 
−
* A third TGEM amplifier has been fabricated
 
  
−
===February===
 
  
−
* A third THGEM card is installed, the detector is ready to test with cosmic rays.
+
[[File:measurements_1.pdf]]
−
* New flex circuit adapter cards have been stuffed with connectors. The 16 signals on five 20 pin connectors will be merged onto one 130 connector used by the digitization cards. 
+
[[File:measurements_2.pdf]]
−
* New HV-circuit  design is ready to give the needed voltage to operate  three THGEM cards simultaneously with the cathode.
+
[[File:measurements_3.pdf]]
−
* A gas system is currently in place with a 50 micron filter and a flow meter.  Check valves are being sought to support a system using 2 supply tanks for continuous operation.  The check valves will allow an empty tank to be replaced while the gas system continues operating on a second tank.
 
  
  
−
Look for NE213 and NE230 liquid scintillator detectors for fast neutrons.  Does the neutron leave the detector?
 
  
−
===March===
+
Conclusion
  
−
*The detector's cathode-TGEM distance had to be increased in order to avoid a spark discharge problem was found when testing the detector at HV using cosmic rays.
+
[[File:conc.pdf]]
−
*A modification took place on the detector's cavity by raising up the detector's widow 5 cm which helped to increase the distance between the cards.
 
  
−
===April===
+
=alpha calibration=
  
−
* A setback to the project occurred when a spark discharge event, during excessive testing, destroyed our 3 THGEM pre-amplifiers.
+
[[File:ch_alphaE.png | 150px]]
−
*Seven FR4 cards, coated with resistive paste, were submitted to the machine shop in ISU and they will be ready in the time after May 15.
 
  
−
===May===
 
−
* Two new THGEM cards and cathode have been installed in the THGEM detector. the card testing is going according to the procedure mentioned below.[[https://wiki.iac.isu.edu/index.php/Neutron_TGEM_Detector_Abdel#5.2F26.2F11]]
 
  
 +
[[File:Raw_data_all.pdf]]
  
−
===June===
 
  
−
*Three THGEM cards were installed in the gas chamber, a procedure is taken for testing the cards to have the smallest gap between the THGEM cards without any discharge. The result, a group of  3 THGEM cards with an average voltage of 2.1kV are stacked together with a separation distance of 3.2mm without observing any discharge effect.
+
The main peaks are for the following channel numbers,
  
−
* The next step is adding the the cathode to 3 THGEM cards then trying to operate the detector.
+
  You need to redo these plots in publication quality with proper axis labels containing units.
  
−
=1/13/11=
+
[[File:ch_alphap1.png | 150px]]
 +
[[File:ch_alphap2.png | 150px]]
  
−
;Sparking Test
+
{| border="1" cellpadding="4"
 +
|-
 +
|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=
 +
 
 +
[[File:gamma_spect.png | 150px]]
 +
 
 +
= Last runs=
  
−
Sparking test for the HT-THGEM of holes size(76) and rim (63)
 
  
 
{| border="1" cellpadding="4"
 
{| border="1" cellpadding="4"
 
|-
 
|-
−
|Separation distance (mm) || type of gas surrounding || V1GB (kV)|| V1GT(kV) || V2GB (kV) || V2GT (kV)|| Notes
+
|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
 
|-
 
|-
−
| 6.5      || Ar/CO2 || 0  || || || ||  
+
|9035 || 06/15 21:06 || 06/13 21:16|| 10 || closed || off || 27 || GEM2.8kV 3.5kV
 
|-
 
|-
−
| 5.0      || Ar/CO2  || 0  || || || ||  
+
|9036 || 06/17 14:48 || 06/17 14:58|| 10 || closed || off || 28 || GEM2.8kV 3.5kV
 
|-
 
|-
−
| 2.6      || Ar/CO2  || 0  || -2 || +2 ||-3 || sparking on the edge then holes starts to spark too  
+
|9037 || 06/17 14:59 || 06/17 14:09|| 10 || open || off || 28 ||  GEM2.8kV 3.5kV
 
|-
 
|-
−
| 2.6      || Air/CO2 || 0  ||-2 ||-2 ||0 || no sparking.
 
 
|}
 
|}
  
−
where:
+
The charge spectrum returned to were it was before the neutron exposure after 29 days for closed shutter.
  
−
V1GB = bottom of the first THGEM card which is placed 2 mm above the charge collector
+
=QDC TDC PS-ADC setup=
  
−
V1GT = top of the first THGEM card
+
;Peak sensing gate
  
−
V2GB = bottom of second THGEM card just above the first TGEM card.
+
[[File: GEM_PS_gate.png | 300 px]]
  
−
V2GT  = top of second THGEM card.
+
;QDC gate
  
−
[[File:sparking_test.png |300px]]
+
[[File: GEM_QDC_gate.png | 300 px]]
  
−
=1/21/11=
 
  
−
* The THGEM card is still sparking because of the hook up wires; which are tested up to 600V by the manufacturer.
+
;TDC start
  
−
The maximum voltage applied for one card only is 2000V on the top and 2000V on the bottom of the card. As soon as the voltage increases more than 2000V on the bottom of the card. a spark is seen in the hole that contains the hook up wire. There is an insulation problem may get serious specially if we still planning to apply 4kV and 6kV on the THGEM card.
+
[[File: TDC_pulser.png | 300 px]]
  
−
The following website is offering hook up wires solid core and can hold up to 2000V, 24 gauge size.
 
  
−
http://caledonian-cables.com/product/Hoop-Up_Wire/UL_1430_Hoop-Up_Wire.htm
+
;TDC STOP
  
−
we may use the wires supported by the glu to have a good insulation.  
+
[[File: TDC_GEM.png | 300 px]]
  
−
*Next step is to repeat the experiment again but after adding the glu on the soldered parts.
+
;QDC shows a difference
  
−
=2/14/11=
+
[[File: QDC_source_on_off_7724_7726.png | 300 px]]
  
−
;Leakage current test:
+
=Measurements of the frequently used gas mixture 90/10 Ar/CO2 for the second peak =
 +
 
 +
;Changes from the former set up
 +
 
 +
# Using the eG&G timing filter amp. 474 instead of the spectroscopic amp. to amplify the input for the peak sensing ADC.
 +
#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
 +
 
 +
[[File: PS_l1.png | 300 px]]
 +
 
 +
;Detected
 +
 
 +
 
 +
[[File: PS_d1.png | 300 px]][[File: PS_d2.png | 300 px]]
  
−
On Thur. 2/10 the leakage current measured for the max. voltage (around 300V) was in 25 nA using user1 setup.
 
  
−
Today the measured current for the voltages shown in the table using user0 setup in clean environment:
 
  
 
{| border="1" cellpadding="4"
 
{| border="1" cellpadding="4"
 
|-
 
|-
−
|Source Voltage(V) || GEM Voltage (V) || Current (uA) || Notes
+
|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 [[File: gate delay700ns.png | 300 px]]
 
|-
 
|-
−
| 500      || 196 || 6.1 || Sparking rate was high in the beginning, higher current observed in a higher sparking rate
+
|7446 || 08/25/14|| 21:29:51|| 21:38:55 || || open || off ||  185 || does not count for P_B. peak disappeared
 
|-
 
|-
−
| 570      || 224 || 23 || GEM sparking rate decreased after a while, current most of the time in the range of the noise level
+
 
 +
 
 
|}
 
|}
  
  
−
Switching to user1 setup when the voltage applied 224V on GEM foil, the maximum current measured was around 10um. The result is not enough to compare the accuracy of the two setups, but it gives a feeling that user1 setup is underestimating.
+
[[File: shutteropen_sourceon_off.png | 300 px]]
  
 +
= unknown gas mixed bottle measurements=
  
−
* The 3rd THGEM card is ready to pick up, the vendor suggested to find another place to do the one with massive number of holes since this semester there is not any time available to do it.
 
  
−
I will start working to collect the 3 cards together using the high voltage circuit distribution, an adjust is going to take place to get the desired voltage for the 3 cards in addition to the cathode.
+
; Updates
  
−
=2/15/11=
+
Changing the leading edge disc. to understand the Peak sensing and explain the cut int he peak sensing graph.
  
−
The following figure shows the elastic xsection and fission xsection for U-238:
+
Measuring the noise. by starting by low signal rate to distinguish the signal from the noise.
  
 +
; Channels and signals
  
−
[[File:ela_fiss.png |300px]]
 
  
 +
{| border="1" cellpadding="4"
 +
|-
 +
|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
  
−
The elastic scattering is higher over the energy range of 5-14 MeV, the probability for the U-238 to recoil is higher than that to have a fission.
+
|-
 +
|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
 +
|}
  
−
=2/17/11=
 
  
 +
{| border="1" cellpadding="4"
 +
|-
 +
|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
  
−
* The high voltage circuit is ready to get a voltage up to 9 kV from the source to provide a voltage up to 2 kV for each THGEM card and potential difference between successive cards up to 115 V (between the high voltage sides) and 80 V (between successive low voltage sides).
+
|-
 +
| 7274|| 08/06/14 || 11:49:35 || 18:15:01 ||  23126 || closed || off || 39 || 0.1 flow rate
  
−
===2/22/11===
+
|-
 +
| 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
  
−
[[Image:2_lines _THGEM_2_lines _THGEM_circuit.png | 200 px|thumb|Circuit 1]]
+
|-
−
The operating voltage for the HV-circuit is 5kV, the voltages on the sides of the THGEM cards is as the following:
+
| 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
  
−
{| border="1" cellpadding="4"
 
 
|-
 
|-
−
|Source Voltage(kV) || THGEM_T1 (kV) || THGEM_B1 (kV)Current (uA) || THGEM_T2 (kV)Notes ||THGEM_B2 (kV)||THGEM_T3 (kV)|| THGEM_B3 (kV)
+
| 7299|| 08/10/14 || 19:27:12|| 20:09:04 || 2152||closed || on ||  107 || 0.1
 +
 
 
|-
 
|-
−
| 5.15    || 5.15 || 2.92 || 5.00 || 2.88 || 2.49 || 1.90
+
| 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
  
−
But in the case of connecting the two circuits together, the effect of the capacitor extends to the other circuit causing the difference in voltage between top and bottom of each THGEM cards is only 0.5kV.
+
|-
 +
| 7305|| 08/11/14 ||  13:21:16||  13:55:05 || 2029||open || on ||  178 || 0.3
  
−
=3/10/11(HV_circuit)=
+
|-
 +
| 7306|| 08/11/14 ||  14:41:00||  15:40:00 || 3540||closed || on ||  110 || 0.3
  
−
;New design for HV-circuit
+
|-
 +
| 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.
  
−
A new design is ready to feed the THGEM cards with voltage difference up to 2kV between the top and the bottom side of the card. Also source drops gradually according to that difference from 6 kV (operating voltage) to 0.1 on the bottom of the card which is closer to the read out card.
+
|-
 +
| 7311|| 08/14/14 || 11:19:45 || 13:01:57 ||  6132 || open || off || 52 || 0.1 flow rate was not exact, little less.
  
−
The follwing table shows the voltage distribution to the cards as the voltage source rises from 4 kV up to 6.5 kV.
+
|-
 +
| 7312|| 08/14/14 ||  13:10:50 || 14:28:07||  4637 || open || off || 72 || 0.1 flow rate was not exact, little less.
  
−
{| border="1" cellpadding="4"
 
 
|-
 
|-
−
|Voltage source (kV)+_ 0.01|| THEGM card number || Top side voltage(kV)+_ 0.01 || Bottom side voltage (kV)+_ 0.01 ||Voltage difference between the two sides (kV)+_ 0.01
+
| 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
 
|-
 
|-
−
| 4.06    || 1 || 4.06 || 2.85 || 1.21
+
| 7333|| 08/17/14 ||  07:05:50 || 08:53:54 ||  || open || on || 155  || 0.1 flow rate
 
|-
 
|-
−
|     || 2 ||  2.36 || 1.44 || 0.92
+
 
 +
| 7334|| 08/17/14 ||  08:57:02 || 13:13:38 ||  || open || off ||  82 || 0.1 flow rate
 
|-
 
|-
−
|     ||  3||  1.38 || 0.08 || 1.3
+
| 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
 
|-
 
|-
−
| 4.50    || 1 || 4.50 || 3.15 || 1.35
+
|7338|| 08/17/14 ||  14:31:37|| 16:17:45||  || open || on || 163  || 0.1 flow rate
 
|-
 
|-
−
|     || 2 ||  2.71 || 1.58 || 1.13
+
 
 +
|7339|| 08/17/14 ||  16:20:25|| 16:35:45 || || open || off || 1368  || 0.1 flow rate, noise measurements with the wave generator
 
|-
 
|-
−
|     ||  3||  1.54 || 0.08 || 1.46
+
 
 +
|7340|| 08/17/14 ||  16:37:01 || 20:33:04||  || open || off || 95 || 0.1 flow rate
 
|-
 
|-
−
| 5.00    || 1 || 5.00 || 3.55 || 1.45
+
|7341|| 08/17-18/14 ||  20:40:16|| 06:18:43 || || open || off || 0.0015  || 0.1 flow rate, triple coincidence
 
|-
 
|-
−
|     || 2 ||  3.06 || 1.86 || 1.20
+
|7342|| 08/18/14 ||  06:25:44 || 06:37:43 || || open || on || 1403  || 0.1 flow rate, noise measurements
 
|-
 
|-
−
|     ||  3|| 1.80 || 0.11 || 1.69
+
|7345|| 08/18/14 ||  06:39:23 || 14:17:58 || || open || on ||0.0128  || 0.1 flow rate, triple coincidence
 
|-
 
|-
−
| 5.50    || 1 || 5.50 || 3.81 || 1.69
+
|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
 
|-
 
|-
−
|     || 2 ||  3.74 || 2.04 || 1.78
+
|7356|| 08/18/14 ||  20:03:05|| 20:07:58 || || open || on || 2k  || 0.1 flow rate, noise measurement
 
|-
 
|-
−
|     ||  3||  1.98 || 0.12 || 1.86
+
|7357|| 08/18/14 ||  20:08:43 || 22:48:22 |||| open || on || 142 || 0.1 flow rate
 
|-
 
|-
−
| 6.00    || 1 || 6.00 || 4.00|| 2.00
+
|7358|| 08/18-19/14 ||  22:53:13 || 10:52:44|| || open || on || 0.0082  || 0.1 flow rate , triple coincidence
 
|-
 
|-
−
|     || 2 ||  3.93 || 2.06 || 1.87
+
|7359|| 08/19/14 ||  10:55:49|| 10:59:52 || || open || on || 2.1k  || 0.1 flow rate , noise measurement
 
|-
 
|-
−
|     ||  3||  2.00 || 0.23 || 1.77
+
 
 +
|7360|| 08/19/14 ||  11:00:38|| 14:26:38|| || open || on ||  156|| 0.1 flow rate  noise measurement with  1 Hz sampling
 
|-
 
|-
−
| 6.1    || 1 || 6.10 || 4.08|| 2.02
+
|7361|| 08/19/14 ||  14:40:49||18:25:00 || open || on || 0 || 0.1 flow rate  with  1 Hz sampling (AND gate)
 
|-
 
|-
−
|     || 2 ||  4.00 || 2.10 || 1.90
+
|7362|| 08/19/14 ||  18:33:15||  18:38:54|| ||open || on ||1.5k  || 0.1 flow rate triple coinc.(OR)
 
|-
 
|-
−
|     ||  3||  2.04 || 0.23 || 1.81
+
|7363|| 08/19-20/14 ||  18:39:46||  13:39:45|| ||open || on ||0.0081  || 0.1 flow rate triple coinc.(OR)
 
|-
 
|-
−
| 6.2    || 1 || 6.20 || 4.15|| 2.05
+
|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
 
|-
 
|-
−
|     || 2 ||  4.06 || 2.13 || 1.93
+
|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
 
|-
 
|-
−
|     ||  3||  2.07 || 0.24 || 1.83
+
|7368|| 08/20/14 ||  16:53:42||  17:15:49||  ||open || on || 154 || 0.1 flow rate
 
|-
 
|-
−
| 6.3    || 1 || 6.30 || 4.21|| 2.09
+
|7369|| 08/20/14 ||  17:17:39|| 20:28:43||  ||open || off || 86  || 0.1 flow rate, spec. amplifier decreased from 100 to 50
 
|-
 
|-
−
|     || 2 ||  4.13 || 2.17 || 1.96
+
|7479|| 08/27/14 ||  10:02:21|| 10:42:09||  ||open || on || 64  || 0.1 flow rate,
 
|-
 
|-
−
|     ||  3||  2.11 || 0.24 || 1.87
+
|7480|| 08/27/14 ||  10:46:18||  14:17:22 || ||open || off || 11 || 0.1 flow rate,
 
|-
 
|-
−
| 6.52    || 1 || 6.52 || 4.47|| 2.05
+
|7481|| 08/27/14 ||  14:19:33 || 14:43:39 || ||close || on || 78  || 0.1 flow rate,
 
|-
 
|-
−
|     || 2 ||  4.28 || 2.39 || 2.11
+
|7488|| 08/27/14 ||  16:16:37 || 16:48:53  || || open|| on || 86  || 0.1 flow rate,
 
|-
 
|-
−
|     ||  3||  2.33 || 0.14 || 2.15
+
|7491|| 08/27/14 ||  18:09:27 || 18:59:05 || || open|| on || 86  || 0.1 flow rate,
 
|}
 
|}
  
−
THGEM card number 1 is the closest to the cathode. THGEM card number 3 is the closest to the readout card.
 
  
−
[[File:THGEM_HV_Series.png |300px]]
+
==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
  
−
* When the voltage is 6 kV, the current that passes through the circuit is <math> I = 6000/42 Mohm = 142 uA </math>
 
  
−
=3/18/11=
+
{| border="1" cellpadding="4"
 +
|-
 +
| Source On|| Source Off
 +
|-
 +
|7507 || 7506
 +
|-
 +
|7509 || 7508
 +
|-
  
−
;Sparking Cathode
+
|7511 || 7510
 +
|-
 +
|7513 || 7512
 +
|-
  
−
The cathode is still sparking even when it is replaced by another new one with the same dimension and distance from the THGEM cards. when I tried to make a little higher I could not since the top part of the detector has less space to get the increment in height.
+
|7515 || 7514
 +
|-
 +
|7517 || 7516
 +
|-
  
−
Machining the top part is important to get more distance for the cathode to avoid the sparking (minimum another 2 cm and if it is more it would be better).
+
|7519 || 7518
 +
|-
 +
|7521 || 7520
 +
|}
  
−
if we succeed to get that space, then a longer corner screw  can be installed to give us a little flexibility to get a better distance for the cathode as it is mounted vertically.
 
  
 +
[[File:unknownbootle_measurements_06_13.png | 300px]][[File:unknownbootle_measurements_14_21.png | 300px ]]
  
−
=4/4/11=
 
  
−
* The detector window's extension is completed and it is test, totally sealed without any gas leakage.
+
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.
  
−
[[File: detector_window_extention.jpg  |300px]]
+
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>
  
−
=4/9/11=
+
[[File:temp_signal_effect.jpg | 300px]]
  
−
* The THGEM is tested to look for a signal, Na-22 and Co-60 sources were used for this purpose, the result that New kind of peaks were detected followed by a tail. Unfortunately the test did not reach the full voltage capacity (up to 6.5 kV) but it was operating under 4.5 kV.
+
=Flow rate and figures=
  
−
* The detector was tested again before removing the cards without Ar/CO2 gas, the applied voltage on the cards was up to 2.5-2.7 kV, without any sparking, cathode was under 8 kV, without any sparks, I excluded the distance between the cards is small to cause a spark, otherwise I won't be able to reach that high voltage without any sparks.
+
;03 flow rate
  
−
* The detector was inspected after the test,  signs of sparking were very clear on the THGEM, and they all located in the same side for the 3 cards but in different degrees of burns (the bottom one was he worst). Through the inspection  I was wondering how can they all be burnt on the same side of the card ?????
+
[[File: 03_sourceOn.png | 450 px]]
 +
[[File: 03_sourceoff.png | 450 px]]
 +
[[File: 03_openOn_off_sub.png | 450 px]]
 +
;02 flow rate
  
−
=4/13/11=
+
[[File: 02_sourceOn.png | 150 px]]
−
* The detector was tested without the cathode, the maximum voltage was 6 kV without sparking, looks the distance should be increased to exclude it of being a reason for sparking and to hit 6.5 kV easily.
+
[[File:02_sourceoff.png | 150 px]]
 +
[[File: 02_openOn_off_sub.png | 150 px]]
  
−
* The distance is increased to about 1 mm, the detector is tested again and we hit 6.3 kV as maximum voltage on the THGEM without the cathode.
+
01 flow rate
  
−
=4/14/11=
+
[[File: 01_sourceOn.png | 150 px]]
−
* The distance between the THGEM is increased to another 1mm ( to have a total of 0.5 cm), the cathode is added to the group with a maximum distance from the top THGEM card, observation will uploaded as soon as possible.
+
[[File:01_sourceoff.png | 150 px]]
  
 +
= Common Start Common Stop exchange=
  
−
=4/18/11(HV-probe)=
+
Edit the file
  
 +
cd /usr/local/coda/2.5/readoutlist/v1495trigPAT/
  
 +
as the following:
 +
 +
for common start comment:
 +
/* c775CommonStop(TDC_ID);
  
−
The following is a list of what is available in the markets:
+
for common stop uncomment:
−
 
+
  c775CommonStop(TDC_ID);
−
http://shop.ebay.com/i.html?rt=nc&LH_BIN=1&_nkw=probe+high+voltage&_dmd=1&_sop=12&_trksid=p3286.c0.m301
 
−
 
 
−
 
 
−
This is what the IAC are using :
 
−
 
 
−
http://cgi.ebay.com/FLUKE-80K-40-AC-DC-HIGH-VOLTAGE-PROBE-/190503643488?pt=LH_DefaultDomain_0&hash=item2c5ae6e960
 
−
 
 
−
 
 
−
I think this is good for our our application , (the price with shipping = 119 + 7 +_ 1) :
 
  
−
http://www.mouser.com/ProductDetail/BK-Precision/HV-44A/?qs=sGAEpiMZZMtNaRJxj63fb%2F49ig1SXyqg1%2FPoyVZEbeA%3D
+
=Ionization xsections for different particles emitted from U-233=  
  
 +
; Photons
  
−
=5/26/11=
+
[[File: photoabosorption_Ar.png | 150 px]]
−
There are new 6 THGEM cards machined and ready for installation.
+
[[File: photoabosorption_CO2.png | 150 px]]
 +
[[File: photoabosorption_Ar_CO2.png | 150 px]]
  
−
* Steps of Installing the new THGEM cards
+
Ref. : http://physics.nist.gov/PhysRefData/Xcom/html/xcom1.html
  
−
1- Cleaning the chamber under the laminar hood.
 
  
−
2- Cleaning the card very well by alcohol and be sure there is not any place on the surface that may collect charge.
+
;Electrons
  
−
3- Installing a card then performing the discharge test up to 2 kV.
+
[[File: electron_ion_Ar.png | 150 px]]
  
−
4- whenever the card passes the discharge test another card will be added until 3 cards installed in the chamber.
+
Ref. :
  
−
5- Adding the cathode to an appropriate distance in a way the charged particle range is covered within this distance and there is not any discharge.
+
Data Nucl. Data Tables 54 (1993) 75  [[File: electron_ionization_Ar.pdf]]
  
−
* Procedure for adding an alpha source film to the detector to test the detector signal???? Please add your comments.
 
  
 +
;Alpha Particles
  
−
* GEANT4 changes:
+
[[File: alpha_ionization.png | 150 px]]
  
−
A discussion about the ENDF data used by GEANT4 9.4 that does not include Th-232 fission cross section, the collaborators recommended me to contact Tatsumi for more information about the Th-232 and U-238 cross sections . He sent me a files that I can install in GEANT4 ENDF directory, I ma going ot repeat the simulation again for U-238 target of thickness of 1 um to measure the to calculate the fission cross section. They also recommend me to contact the INCL model programmer and discuss with him the issue of underestimating the values of the fission cross section in our simulation.
+
Ref. :
  
−
I am going to start my simulation on BREMS using the new fission cross section file. Is that ok?
+
http://www.exphys.jku.at/Kshells/
  
 +
Data Nucl. Data Tables 54 (1993) 75
  
−
===Summary or testing 3 THGEM cards with a distance of 7.5 mm without a cathode===
+
=Coincidence Measurements for GEM and the Plastic scintillator=  
  
−
; Table of observations:
+
;Coincidence Measurement for the scintillator PMT's without shielding and without source
  
 
{| border="1" cellpadding="4"
 
{| border="1" cellpadding="4"
 
|-
 
|-
−
|Date and time || Test Duration||Voltage source <math>(kV) \pm 0.01 </math>  || Current <math>(\mu A) \pm 1 </math>  || Notes
+
|Date || Time || No. of Counts (counts)|| Count rate (counts/min)  
 
|-
 
|-
−
|6/22/11      || N/A ||6.5  || 150 || the power supply tripped directly
+
|07/09/14 || 1066 || 659005 || 618
 
|-
 
|-
−
|6/23/11  5:45-6:45am || 1hr || 6  || 137 || increment 20V until 5.5V then 5V until 6 kV
+
|07/10/14 || 538 || 368974 || 686
 
|-
 
|-
−
|6/23/11  7-7:05am  || 5min|| 6.2  || 145 || increment 20V until 5.5V then 5V until 6.2 kV
 
−
|-
 
−
|6/23/11  7:23-7:30am  || 7min || 6.2  || 143 || increment 20V until 5.5V then 5V until 6.2 kV
 
−
|-
 
−
|6/25/11  7:30-8:10pm  || 50min || 6.3  || 145 || increment 20V until 5.5V then 5V until 6.3 kV (T-shape connector divides the signal between the discriminator with a voltage of 0.4V and the oscilloscope)|| [[File:6.3k_148uA_halfspark_6_25_11.png | 50 px]]
 
−
|-
 
−
|6/27/11  11-11:40am  || 30min || 6.2  || 144 || increment 20V until 5.5V then 5V until 6.2 kV (weekend)
 
−
|-
 
−
|6/27/11  2-2:32pm  || 32min || 6.2  || 144 || increment 20V until 5.5V then 5V until 6.2 kV|| [[File:6.2k_144uA_halfspark_6_27_11.png | 50 px]]
 
  
−
|-
 
−
|6/28/11  5pm-3:30pm  || 22.5hr || 5.5  || 125 || increment 20V and there is not any discharge
 
−
|-
 
−
|6/28/11  3:30-3:45pm  || 15min || 6  || 137 || over night at 5.5kV then 5V until 6 kV
 
−
|-
 
−
|6/29/11  3:30-3:45pm  || 15min || 6  || 137 || over night at 5.5kV then 5V until 6 kV || [[File:6k_140uA_halfspark_6_29_11.png |50px]]
 
−
|-
 
−
|6/29/11  4:30pm-5:30am  || 13hr || 5.5  || 125 || increment by 5V, a discharge is observed but it was not enough to trip || [[File:5.5k_140uA_halfspark_6_29_11.png |50px]]
 
−
|-
 
−
|6/30/11  6:40pm-7:20am  || 40min || 6  || 137 || increment by 5V and 15 min waiting time every 100V , proving the current when it is needed || [[File:6k_138uA_halfspark_6_30_11.png |50px]]
 
  
−
|-
+
 
−
|7/1/11  9:15pm- 8:10am(or earlier)  || 9 || 5.5  || 124 || increment by 5V, a discharge is observed by the time mentioned || [[File:5.5k_124uA_halfspark_7_1_11.png |50px]]
 
−
 
 
|}
 
|}
  
−
==7/5/11==
 
−
*The vertical distance between the THGEM card is 9 mm except for top one that follows the union, it has a distance of 11mm.
 
  
  
−
{| border="1" cellpadding="4"
+
;Triple coincidence Measurement for the scintillator PMT's shielded and without source
−
|-
 
−
|Date and time || Time before HV trip||Voltage source  <math>(kV) \pm 0.01 </math>|| Current <math>(\mu A) \pm 1 </math>  || Notes || discharge picture
 
−
|-
 
−
|  7/5/11_2:53-2:58pm  ||  5 min || 6.1  || 140 || The voltage is gradually increased and sets for 45 min. as it is 6kV|| [[File:6.1k_140uA_halfspark_7_5_11.png |50px]]
 
−
|-
 
−
|  7/5/11_7:25pm-11pm  || 4.55 h  || 5.5  || 125 || No discharge 
 
−
|-
 
−
|  7/5/11_11pm-5am  || 6h  || 5.75  || 130 || Discharge with small peaks || [[File:5.75k_130uA_halfspark_7_6_11.png |50px]]
 
−
|-
 
−
|  7/6/11_5:50am-12:30pm  || 6.64  || 5.75|| 130 ||test is running for more than 6h, looks it was accidentally sparking in the previous test
 
−
|-
 
−
|  7/6/11_12:33pm-1:48  ||  1.15h || 6  || 137 || power supply tripped without discharge detected
 
−
|-
 
−
|  7/6/11_2pm-3pm  || 1h  || 6  || 137 || discharge|| [[File:6k_137uA_halfspark_7_6_11.png |50px]]
 
−
|-
 
−
|  7/6/11_9:15-11:15pm  || 2h  || 6  || 137 || discharge|| [[File:6k_137uA_halfspark_7_6_11_NO2.png |50px]]
 
−
|-
 
−
|  7/7/11_5:46-5:50am  ||  4min || 6  || 137 || 1.04V noise|| [[File:6k_137uA_halfnoise_7_7_11.png |50px]]
 
−
|-
 
−
|  7/7/11_6:25-6:30am  ||  5min || 6  || 137 || discharge|| [[File:6k_137uA_halfspark_7_7_11.png |50px]]
 
−
|}
 
  
−
==7/8/11==
+
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.
  
−
*The THGEM cards have insulating layers on both sides covering the copper frame, the separation distance is still as mentioned above (9mm and 11 mm after the union). The tests for the THGEM are represented by the following table:
 
  
−
{| border="1" cellpadding="4"
+
[[File: GEM_triple_smallpeak.png | 150 px]]
−
|-
+
[[File: GEM_triple_bigpeak.png | 150 px]]
−
|Date and time || Time before HV trip||Voltage source  <math>(kV) \pm 0.01 </math>|| Current <math>(\mu A) \pm 1 </math>  || Notes || discharge picture
+
[[File: GEM_triple_twopeaks.png | 150 px]]
−
|-
 
−
|  7/8/11_6:10-7:15am  ||  1.1h || 6  || 137 || discharge|| [[File:6k_137uA_halfspark_7_8_11.png |50px]]
 
−
|-
 
−
|  7/8/11_12:45-2:15pm  || 1.5h  || 5.9  || 134 || discharge|| [[File:5.9k_133uA_halfspark_7_8_11.png |50px]]
 
−
|-
 
−
|  7/9/11_1-5pm ||  4h ||  5.9 || 134 || no discharge
 
−
|-
 
−
|  7/9/11_5:03-5:15pm || 12min. ||  6 || 137 ||discharge || [[File:6k_137uA_halfspark_7_9_11.png |50px]]
 
−
|-
 
−
|  7/9/11_8:10pm  || 0  || 5.5  || 125 || discharge|| [[File:5.5k_125uA_halfspark_7_9_11.png |50px]]
 
−
|-
 
−
|  7/10/11_1:30pm-8  || 6.5h|| 6 || 137 || discharge ||  [[File:6k_137uA_halfspark_7_10_11.png |50px]]
 
−
|-
 
−
|  7/10/11_10:05pm-4:50am  || N/A|| 6 || 137 ||the power supply is tripped 
 
−
|}
 
−
Why aren't you able to have at least 4 measurements each day?
 
  
−
A: I do sometimes a test directly after the last test ends, I do not observe the reproducibility, which make me think I have to wait a little to get consistency in the tests' results,(the last two tests are only 3h apart! )
+
=Coincidence Measurements for the Plastic scintillator after shielding=
  
 +
; Without source
  
−
Also, a 2.5V noise detected in certain times and I can not avoid, and it trips the power supply.( for example, Sat. 7_9_11 appears frequently, oscilloscope picture is shown below).
+
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.
  
−
[[File:5.5k_125uA_noi_7_9_11.png |50px]]
 
  
−
The image above  does not look like a spark
+
;With a source
  
−
Perhaps your trip threshold is too low?
+
=Background count rate=
  
−
What voltage is your threshold set at?
 
  
−
A: at the time of the test was 0.4V. The maximum voltage by the discriminator is 1V.
+
{| border="1" cellpadding="4"
 +
|-
 +
|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 ||
  
−
Q: Will I be able to avoid it using the recent discriminator or I should have another one with a higher voltage threshold?
 
  
 +
|}
  
−
=7/12/11=
+
= data graphs=
  
−
An attenuator is added to the circuit to decrease the amplitude any pulse detected to a fifth of the original value, the discriminator voltage is set to 0.5V so a discharge or a noise of >= 5V  will trip the power supply.
 
  
 +
;<math>S_{HLE}</math>
  
  
−
The following table shows the new tests results with the new settings.
+
[[File: B_pdaily_counts.png | 150 px]]
  
−
{| border="1" cellpadding="4"
+
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.
−
|-
 
−
|Date and time || Time before HV trip||Voltage source  <math>(kV) \pm 0.01 </math>|| Current <math>(\mu A) \pm 1 </math>  || Notes || discharge picture
 
−
|-
 
−
|  7/13/11_10:30-11:30am  ||  1h || 6.1  || 140 || No noise or discharge
 
−
|-
 
−
|  7/13/11_11:35am-12:05pm  ||  0.5h || 6.2  || 143 || noise|| [[File:6.2k_143uA_halfnoi_7_13_11.png |50px]]
 
−
|}
 
  
  
−
Can you detect a spark still?
+
;<math>S_{PSD}</math>
  
−
I made the circuit in away that I can see the half spark before it is attenuated.
 
  
−
For the 2nd time I see the following noise tripping the power supply but I do not know why!!!
+
[[File: S_pdaily_counts.png | 150 px]]
  
−
[[File:6k_137uA_halfnoi_7_13_11.png |50px]]
+
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).
  
−
Perhaps the scope missed the spark signal that caused the trip?
 
  
−
I am thinking to install the cathode, should I? and I will keep working to improve the circuit to trip the voltage when it is 5 V or more.
+
  Small=<math>S_{PSD} - S_{PSDE}</math>
  
 +
=Testing GEM Experiment  test 10/23/13=
  
−
No cathode Yet,  we need the smallest distance between THGEMs which will hold 6.2 - 6 kV without sparking.  I expect sparks to happen within an hour or less.
+
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.
  
−
=7/13/11=
+
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.
  
−
*The separation distance between the THGEM cards is 6.1mm including the one between the last THGEM and the readout plate.  The gas will flow overnight at low rate to get the tests by tomorrow morning.
 
  
  
 
{| border="1" cellpadding="4"
 
{| border="1" cellpadding="4"
 
|-
 
|-
−
|Date and time || Time before HV trip||Voltage source <math>(kV) \pm 0.01 </math>|| Current <math>(\mu A) \pm 1 </math>  || Notes || discharge picture
+
| shutter close ||  [[File: GEM_close_1.png | 40 px]]|| [[File: GEM_close_2.png | 40 px]]
 
|-
 
|-
−
|   7/14/11_6:05-7:05am  || 1h  || 6.0  || 138 || no discharge or noise
+
| shutter open || [[ File:GEM_open_1.png | 40 px ]]|| [[File: GEM_open_2.png | 40 px]] || [[File: GEM_open_3.png | 40 px]]|| [[File: GEM_open_4.png | 40 px]]
−
|-
 
−
|  7/14/11_7:20-7:33am  ||  13min || 6.1  || 140 || noise, discriminator level is 0.8V || [[File:6.1k_140uA_halfnoi_7_14_11.png |50px]]
 
−
|-
 
−
|   7/14/11_7:43-8:00am  || 17min  || 6.1  || 140 || noise || [[File:6.1k_140uA_halfnoi_7_14_11_2.png|50px]]
 
−
|-
 
−
|  7/14/11_8:17-9:17am  ||  1h || 6.1  || 140 || no discharge or noise, attenuator level set to a tenth, discriminator 0.4V 
 
−
|-
 
−
|  7/14/11_9:18-10:18am  ||  1h || 6.2  || 143 || no discharge or noise
 
 
|}
 
|}
  
−
=7/14/11=
+
=THGEM#9 Counting Experiment  test 1/4/13=
−
*Test results when the separation distance is 3.2mm.
 
  
−
{| border="1" cellpadding="4"
 
−
|-
 
−
|Date and time || Time before HV trip||Voltage source  <math>(kV) \pm 0.01 </math>|| Current <math>(\mu A) \pm 1 </math>  || Notes
 
−
|-
 
−
|  7/14/11_5:50-6:50am  || 1h  || 6.0  || 139 || no discharge or noise, discriminator 0.25V 
 
−
|-
 
−
|  7/14/11_6:54-7:54am  || 1h  || 6.2  || 144 || no discharge or noise 
 
−
|-
 
−
|  7/14/11_8:01-9:12am  || 1.1h  || 6.5  || 151 ||  no discharge or noise
 
−
|}
 
  
 +
[[THGEM#9 Counting Experiment]]
 +
 +
=GEM HV-divider circuit=
  
−
=7/18/11=
 
  
−
*The cathode gap was 6.1 mm, there was not any signal from the detector when it was tested by the radioactive isotopes. The highest voltage I reached was 6.3 kV for the THGEM cards and 6.4 kV on the cathode, I heard the knocking sound again, I thought it was a spark that does not propagate through the trigger out but it was not.
+
GEM HV-divider circuit in shown in the figure, measurements were recorded for for top and bottom voltage of each preamplifier.  
  
−
* The cathode gap is 9.2 mm, the detector is free from any burns or signs of sparking. The detector will stay overnight under the gas to test it under the same environment tomorrow with the new distance.
+
<center>[[Image:GEM_HV_Dist_Net.jpg | 100px]]</center>
  
  
 +
The table below shows value of the voltage on each  preamplifier's side relative to ground.
  
−
=7/20/11=
 
−
The following is expected to be noise detected when the the the cathode voltage is 6.3kV and the THGEM source voltage is 6.1kV:
 
  
 
{| border="1" cellpadding="4"
 
{| border="1" cellpadding="4"
 
|-
 
|-
−
|[[File: 6.2c_6.1t_half_7_20_11_No1.png |50 px]] ||[[File: 6.2c_6.1t_half_7_20_11_No2.png |50 px]] ||[[File: 6.2c_6.1t_half_7_20_11_No3.png |50 px]] || [[File: 6.2c_6.1t_half_7_20_11_No4.png |50 px]] || [[File: 6.2c_6.1t_half_7_20_11_No5.png |50 px]] || [[File: 6.2c_6.1t_half_7_20_11_No6.png |50 px]]
+
| <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).
  
−
=7/22/11=
+
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.
  
−
*A trial took place today to place an alpha source on the THGEM cathode, unfortunately the source is very fragile and easily breaks into small pieces that may spread inside the detector and causes contamination for any kind of motion for the detector's chamber, I removed everything from the cathode and I cleaned it very well.
+
= GEM alpha-Beta detector counter=
 +
[[GEM Alpha-Beta detector counter]]
  
 +
=GEM gain data graphs and GEM Calibration in LDS=
  
−
=7/25/11 (particle Counter user directions)=
+
==GEM Detector==
  
−
[[Clean Room Particle Counter User Directions]]
+
[[GEM performance QDC data graphs]]
  
 +
[[Calibrating GEM detector]]
  
−
=7/26/11 Installing Radium source =
 
  
−
==Counts Measurement==
+
==Electronics Flow Chart==
  
−
A "Radium C" source was installed.  This is mostly Bismuth-209.
+
[[File:LDS_electronics_flow_chart.png |200px]]
  
−
Using a Lund hand held survey meter Model 2401-P we observed a contact activity between 0.8 and 1.5 mR/hr (2500-5000 CPM), R stands for roentgen.
 
  
−
The detector efficiency is 35.2% (Cl-36), 74.8% (Sr-90), 3.0%( Am-241), 3.5% (C-14), 20.1% (Bi-210), 17.2% (Tc099).
+
==GEM Detector and Scintillator==
  
−
This is the rate of beta particles.
+
[[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.
  
−
The alpha rate is probably 5% of this rate.
+
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
  
−
<math>\frac{1 mR}{hr} \times \frac{ 2.58 \times 10^{-4} C}{R kg} \times \frac{1 e-}{1.6 \times 10^{-19} C} = 2 \times 10^{12} \frac{ions}{kg}</math>
+
;Summary
  
 +
The detector is installed in the IAC after modifications took place in the detector design.
  
−
ArC02 gas volume = 100 cm^3
+
These modifications are:
  
−
===7/27/11===
+
1- The detector kipton window's area  increased to the same size of the GEM cards( 10X10 cm)
  
−
*The detector is tested as the new source is inside, the peak is observed when the voltage 4.8kV and 5.1kV on the THGEM and the cathode successively.The following pulses were observed:
+
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)
  
−
[[File:7_27_11_source_1.png| 200 px]]
+
Increasing the drift distance demands an increase in cathode potential to maintain the same values of the electric field in the old setup.
  
−
;But when the voltage increased to 5.2kV and 5.5kV (THGEM and cathode) I got the pulse inverted!
+
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.
  
−
[[File:7_27_11_source_2.png| 200 px]]
 
  
 +
[[GEM performance data graphs]]
  
−
*Another trial took place today to test the THGEM detector as a radioactive source is inside the gas chamber, the voltage went up to 6.3kV and 6kV that ended up with a  spark  that tripped the power supply. So, the maximum voltage for operating the detector without any discharge is 5.9kV and 6kV for the THGEM cards and the cathode successively.
 
  
 +
==Electronics Flow Chart==
  
−
===oscilloscope compensation error message===
+
[[File:IAC_electronics_flow_chart.png |200px]]
  
−
[[File:7_27_11_compensation_error.png| 200 px]]
 
  
 +
[[File:IAC_n.png |200px]]
  
−
=7/29/11=
+
=U-233 fission x-section data and fission yield=
  
−
==New HV circuit==
+
[[File:U-233_fissionxsection_0.01-100MeV.gif |200px]]
 +
[[File:U-233_fissionxsection_fullenergyrange.gif |200px]]
  
−
*A new high voltage circuit is installed by the following voltage characteristics:
+
[[File:U-233_fissionxyield_percent.png |200px]]
  
−
1- Between The THGEM cards:
+
 
 +
 
 +
== What is the energy distribution of Beta, Photon and alpha from U-233==
 +
 
 +
===Alpha ===
  
 
{| border="1" cellpadding="4"
 
{| border="1" cellpadding="4"
 
|-
 
|-
−
|<math> V_source (kV \pm 0.1)</math> || <math> \Delta V_1 (kV \pm 0.1)</math> ||  <math> \Delta V_2 (kV \pm 0.1)  || <math> \Delta V_3 (kV \pm 0.1)</math>
+
| nuclide || Energy (MeV)
 
|-
 
|-
−
|5.1 || 1.4 || 1.3 || 1.1
+
| Pb-213  || <span style="color:red"> 8.4</span>
 
|-
 
|-
−
|6.1 || 1.7 || 1.6 || 1.4
+
| Bi-213 || 5.9
 
|-
 
|-
−
|7.2 || 2.0 || 1.8 || 1.6
+
|At-217 ||6.3 
−
|}
 
−
 
 
−
 
 
−
2- Relative to the ground:
 
−
{| border="1" cellpadding="4"
 
 
|-
 
|-
−
|<math> V_{source} (kV \pm 0.1)</math> ||<math> V_{THGEM_{T_1}} (kV \pm 0.01)</math> || <math> V_{THGEM_{B_1}} (kV \pm 0.01)</math>
+
|Fr-221 || 6.3
−
||<math> V_{THGEM_{T_2}} (kV \pm 0.01)</math> || <math> V_{THGEM_{B_2}} (kV \pm 0.01)</math>||<math> V_{THGEM_{T_3}} (kV \pm 0.01)</math> || <math> V_{THGEM_{B_3}} (kV \pm 0.01)</math>
 
 
|-
 
|-
−
| 5.1 || 5.10 || 2.46 || 2.43 || 1.19 || 1.17 || 0.07
+
|Th-229 || <span style="color:green">4.85 </span> (alpha spectrum, highest counts for is 4.85 MeV)
−
|-
 
−
| 6.1 || 6.1 || 2.96 || 2.93|| 1.43 || 1.40 || 0.08
 
−
|-
 
−
| 7.2 || 7.2 || 3.49 || 3.45 || 1.69 || 1.66 || 0.09
 
 
|}
 
|}
  
 +
===Gamma===
  
−
* Three THGEM cards are installed with a separation distance of 3mm, resistive paste cathode is used instead of the copper cathode with a separation distance of 9.2mm but it is  without the <math> \alpha </math> source. The chamber will be filled with Ar/<math>CO_2</math> gas overnight to create an appropriate environment for a sparking testing which will be performed by next morning.
+
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>
−
 
 
−
=7/30/11 Table of sparking tests using the new HV circuit for 3 THGEM=
 
−
 
 
−
*The sparking test was performed to test THGEM cards using the HV-circuit, the gas was blown to the chamber for 1h for each test except for the first 3tests. the aim is reach the minimum distance between the THGEM cards with a cathode far enough to cause any sparking.
 
  
 +
The energy range of the emitted gamma is shown in the following table .
  
 
{| border="1" cellpadding="4"
 
{| border="1" cellpadding="4"
−
| Date  || No. of THGEM cards|| THGEM cards distance (mm +_ 0.1) || Cathode is used || Cathode distance (mm +_ 0.1) || voltage (kV+_ 0.1) || Notes || spark picture
 
−
|-
 
−
|7/30/11 || 3 || 3.2|| yes || 9.2|| 6.0C 6.0_S || resistive paste cathode is used || [[File:7_30_11_spark_6kC_6kTH.png |50px]]
 
−
|-
 
−
| 7/31/11 || 3 || 3.2 || yes || 9.2 || 5.7C 5.7_S || the copper frame of resistive paste cathode  is insulated || [[File:7_31_11_spark_5.7kC_5.7kTH.png |50px]]
 
−
|-
 
−
|8/1/11_1p || 1 || 0||no ||0 || 1TH || the card has a distance of 3mm from the readout plate, card replacement with one of others used previously|| [[File:8_1_11_spark_4.6TH_single.png |50px]]
 
−
|-
 
−
|8/2/11_830a || 1 || 0||no ||0 || 1.6TH  || the card has a distance of 3mm from the readout plate, the card passed the test, ringing is observed || [[File:8_2_11_single_ringing.png |50px]]
 
 
|-
 
|-
−
|8/2/11_1219a || 1 || 0||no ||0 || 2.0TH || the card has a distance of 10.5mm from the readout plate, the card passed the test,noise is observed || [[File:8_2_11_single_noise.png |50px]]
+
| nuclide || Energy Minimum || Energy Maximum (keV)
 +
|-|
 +
| U-233 || 25 || <span style="color:red"> 1,119</span>
 
|-
 
|-
−
|8/2/11_3p || 1 || 0||no ||0 || 1.4TH  || the card has a distance of 10.5mm from the readout plate, the card has a local discharge || [[File:8_2_11_single_local_discharge.png |50px]]
+
| Ra-225 || 40 || 40
 
|-
 
|-
−
|8/2/11_940p || 1 || 0||no ||0 || 1.6TH  || the card has a distance of 10.5mm from the readout plate, the card has a local discharge || [[File:8_2_11_single_local_discharge.png |50px]]
+
|Ac-225 || <span style="color:green">10.5 </span> || 758.9
 
|-
 
|-
−
|8/4/11_620a || 2 || 3.2||no ||0 || 1.6TH3 1.8TH2 || THGEM 3 has a distance of 2mm from the readout plate, there is not any local discharge, the setup passed the desired voltage 7.2kV ||
+
|Fr-221 || 96.8 || 410.7
 
|-
 
|-
−
|8/4/11_620p || 3 || 3.2||no ||0 || 6.4S || discharge || [[File:8_4_11_single_discharge.png |50px]]
+
|At-217 || 140 || 593.1
 
|-
 
|-
−
|8/5/11_915a || 3 ||  3.2||yes ||9.2 || 6.4S || discharge ||
+
|Bi-213 || 323.81 || <span style="color:red">1,119.4 </span>
−
|-
 
−
|8/5/11_1p || 3 || 4.5, 3.2||no ||0 || 6.5S  || THGEM1 has a distance of 4.5mm, the other two has 3.2mm separation distance a strong local discharge is observed without tripping the power supply
 
−
|-
 
−
|8/5/11_620p || 3 || 4.5, 3.2||no ||0 || 6.1S  || THGEM1 has a distance of 4.5mm, the other two has 3.2mm separation distance a strong local discharge is observed without tripping the power supply
 
−
|-
 
−
|8/6/11_12p || 2 ||  3.2||no ||0 || 7.2S || discharge after a while and not in the holes area tripped the power suplly, safer to stay around 7kV
 
−
|-
 
−
|8/7/11_9a || 2 ||  3.2||yes ||16.2 || 7.0S 1.8TH2, 1.6TH3, 3.6C|| the detector was stable then discharge started (can be heard) but without tripping the power supplly, before the discharge a pulse  frequently observed || [[File:8_7_11_pulse.png |50px]]
 
−
|-
 
−
|8/7/11_120p || 2 ||  3.2||yes ||16.2 || 7.2S 1.8TH2, 1.6TH3, 3.9C|| an alpha source is installed, the detector was stable then discharge started (can be heard) but without tripping the power supplly, nothing special is observed 
 
−
|-
 
−
|8/9/11_720a || 2 ||  3.2||yes || || 7.3S 1.8TH2, 1.6TH3, 3.8C|| an alpha source is installed, the detector is  stable, pulses were frequently observed || [[File:8_9_pulse4.png |50px]]
 
 
|}
 
|}
  
  
−
=8/19/11 Table of sparking tests using the new HV circuit for 4 THGEM=
+
===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>
 +
 
 +
[[File:U-233_decay_beta_energy.jpg |200px]]
  
−
New HV circuit is installed in the THGEM detector setup, the follwing table shows the results of the testing the the new set up:
+
U-233 -> Th-229, emitted alpha particles have energy of 4.8 MeV.
  
−
  {| border="1" cellpadding="4"
+
  Insert energy distribution for Betas
−
| Date  || No. of THGEM cards|| THGEM cards distance (mm +_ 0.1) || Cathode is used || Cathode distance (mm +_ 0.1) || voltage (kV+_ 0.1) || Notes || spark picture
 
−
|-
 
−
|8/19/11_930a || 4 ||  3.2 and 4.2 between THGEM1 and THGEM2||yes || 4.2 mm || 6.2S  6.1C|| an alpha source is installed, a 1 V negative pulse is observed by the trigout  as shown in the figure as the applied voltage is 5.2kV for Cathode and 5kV for HV circuit source, a spark tripped the voltage which indicates that the detector has a insulation problem in addition to a gas insulation problem || [[File:8_19__11_4TH_pulse1_5.2C_5T.png |50px]]
 
−
|}
 
  
 +
The following table shows the negative beta emitter nuclides,their parent nuclides, and  their half lives:
  
−
== Card testing==
 
  
 
{| border="1" cellpadding="4"
 
{| border="1" cellpadding="4"
−
| Date  || No. of THGEM cards|| THGEM cards distance (mm +_ 0.1) || Cathode is used || Cathode distance (mm +_ 0.1) || voltage (kV+_ 0.1) || Notes || spark picture
 
 
|-
 
|-
−
| 8/24/11 || 1 || 0.0|| yes|| 6.0mm || 2.2kV || card_D is stable, but there is not any signal detected using the alpha-source
+
|Nuclides || energy (MeV) || half life
 +
|-
 +
| <math>Ra^{225} \rightarrow Ac^{225}</math> ||<span style="color:green">0.357 </span> || 14d.
 +
|-
 +
|<math>Bi^{213} \rightarrow Po^{213}</math> || 1.426 || 46min.
 +
|-
 +
|<math>Tl^{209} \rightarrow Pb^{209}</math> || <span style="color:red">1.981 </span> || 2.2 min.
 
|-
 
|-
−
| 8/25/11 || 1 || 0.0|| yes|| 6.0mm || 2.2kV || card_B is stable, but there is not any signal detected using the alpha-source
+
|<math>Pb^{209} \rightarrow Bi^{209}</math> || 0.644 || 3.25h
 
|-
 
|-
−
| 8/29/11 || 2 || 3.0|| yes|| 6.0mm || 4.2S  || card_B isn ot stable, sparking starts at source voltage indicated which will provide the card approximately a voltage difference  of 1.7kV
+
|<math>Bi^{209}</math> || 1.893 || stable
 
|}
 
|}
  
 +
==What is the energy distribution after the 1 mm FR4 shutter==
  
−
=8/31/11 THGEM as an alpha detector =
 
  
−
An alpha source is installed by sticking the source on the center of the cathode. the source has unknown activity but it emits alpha and negative beta with a ratio of 1:6, the source has a vertical separation distance  of magnitude of 3-6mm from the first THGEM card.
+
=== electron shutter penetration===
  
−
===Pictures of mounted source Radium C===
+
The energy distribution below represents the incidence electron on a 1 mm FR4 shutter.
  
−
[[File:THGEM_7-26-11_a.png| 200 px]]
+
[[File:E_spectrum.png |90 px]]
−
[[File:THGEM_7-26-11_b.png| 200 px]]
 
−
[[File:THGEM_7-26-11_c.png| 200 px]]
 
  
 +
graph of electron energy for electron penetrating shutter (did any not penetrate?, how many?)
  
−
===Detector Testing===
 
  
−
* Two resistive paste THGEM cards were installed inside the Flex testing chamber, a readout plate is place in the bottom of the 2nd THGEM, a cathode is mounted at the top of the first. the vertical separation distance is the same for all and equal approximately to 2mm  .
 
  
−
Teh following signal is observed:
 
  
−
=9/14/11=
+
photons below were produced by above incident electron?
 +
The energy distribution of photons was observed on the opposite side of the shutter
  
 +
[[File:Photon_spectrum.png |90 px]]
  
−
My research main goal is to measure the efficiency of Thick Gaseous Electron Multiplier Preamplifiers (THGEM) as a Neutron Sensitive Detector in the range of 1-14 MeV.  The THGEM is constructed using an FR4 substrate that has been coated with a resistive paste.  A staggered array of millimeter size holes are machined in the THGEM.  The resistive paste is removed from the perimeter of the holes in order to reduce the spark discharge probability.    The focus of my work is to dope the resistive paste with a neutron sensitive material.  A determination of the neutron sensitive material type and optimal doping strategy to produces a high detection efficiency is the goal of my work.
 
  
−
=TTL switch Power supply test circuit=
+
Electrons (with least energy from U-233= 0.2 MeV) pass through the shutter have the energy distribution below.
  
−
* The circuit needs 12 resistors, such that as voltage applied is 2.5V, the circuit can hold up a current up to 100000 uA and minimum electric power of 0.5W ( assuming  the value of each resistor is 2 ohm).
+
===alpha shutter penetration===
  
−
*A TTL switch is going to be used by using DG417 [[File:TTL_switch_DG417.pdf]] chip which has the following properties:
+
===photons===
  
 +
== Number of ions produced from Beta and Photon in ArCo2==
  
−
1- It has the following logic table:
+
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).
  
−
[[File: logic table.gif| 200 px]]
 
  
−
2- TTL logic compatibility.
+
[[File:SecondaryElectron_Energy_1Mevbeta.png |90 px]]
  
−
;NAND gate 2.8ns
+
= The needed time  to observe the GEM signal=
  
−
[[File: toshiba_NAND_2.8ns.pdf]]
+
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.
  
−
;Digikey
+
The normal rate (8 MHz +/- 2 as measured by the oscilloscope) is observed after 952.9s +/- 0.1.
  
−
{| border="1" cellpadding="4"
+
=THGEM card tasks and tests=
−
| Logic Gate  || minimum switching time (ns)|| Part Number || weblink || minimum order|| availability
 
−
|-
 
−
| NOT        ||  1 || TC7SET04FFCT-ND || http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=TC7SET04FFCT-ND || 1 || in stoke
 
−
|-
 
−
| NAND || 1.5 || TC74LCX00FNF-ND || http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=TC74LCX00FNF-ND || 1 || in stoke
 
−
|-
 
−
|
 
−
|}
 
  
−
===vendors===
+
;New THGEM cards:
  
−
;dg417
+
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.
  
−
http://search.digikey.com/scripts/DkSearch/dksus.dll?lang=en&site=US&KeyWords=maxim+dg417&x=0&y=0
+
The older THGEM cards will have a high voltage enough to have one spark/min to clean impurities or surface defects.
  
−
;SHV Jack:
+
=GEM Signal after the latest modification on the fission chamber 07/01/13=
  
−
http://www.pasternack.com/product-SHV-Jack-Bulkhead-Rear-Mount-Solder-Cup-Contact-PE4499-70717.html
+
The signal of the detector is observed as the shutter is open and close.
  
 +
{| border="1" cellpadding="4"
 +
|-
 +
| shutter close || [[File: GEM_close.jpg | 40 px]]|| [[File: GEM_close1.jpg | 40 px]]|| [[File: GEM_close2.jpg | 40 px]] || [[File: GEM_open.jpg | 40 px]]
 +
|-
 +
| shutter open || [[ File:GEM_open_7_1.jpg | 40 px ]]
  
−
Most vendors offer the SHV-connector with price between 18-25$
+
|}
  
−
I can not find cheaper price than 18$, but the connector that is attached to testing chamber has cheaper price and available in stoke :  http://www.ebay.com/sch/i.html?_from=R40&_trksid=p5197.m570.l1312&_nkw=SHV+connectors&_sacat=See-All-Categories
 
  
 +
=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%.
  
−
=THGEM card Transparent test chamber=
+
−
 
 
−
The transparent test chamber project is complete.
 
−
 
 
−
The chamber has a gas leakage of 0.4 SCFH (the gas system is well insulated to lower than 0.5 SCFH)
 
−
 
 
−
=Comparison ENDF evaluation of U-238 neutron fission xsection and GEANT4=
 
−
 
 
 
{| border="1" cellpadding="4"
 
{| border="1" cellpadding="4"
 
|-
 
|-
−
|[[File: U_238_xsection_ebars.png |250 px]] ||     [[File: U_238_fxsection_12MeV.png |250 px]] || [[ File:ENDF_GEAN4_U238_fxsection.png |250 px]]
+
| Long bnc cable|| [[File: GEM_longcable1.jpg | 40 px]]|| [[File: GEM_longcable2.jpg | 40 px]]
 +
|-
 +
|  Short bnc cable|| [[ File:GEM_shortcable.jpg | 40 px ]]
 +
 
 
|}
 
|}
  
−
INTERNATIONAL EVALUATION OF NEUTRON CROSS-SECTION STANDARDS, INTERNATIONAL ATOMIC ENERGY AGENCY,VIENNA, 2007 [[File:U238-xsection.pdf]]
 
−
 
−
;absolute f_xsection in the table 7.1 p.91
 
  
 +
=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:
 +
 
{| border="1" cellpadding="4"
 
{| border="1" cellpadding="4"
 
|-
 
|-
−
|Ref. number    || inxn || data description || author || citation || notes 
+
| Shutter position || Alpha particles /min.|| Beta particles /min.
−
|-(f
 
−
|809 || 238U(n,f)|| Absolute ||  G. Winkler et al. || 91Jülich (1991) 514 || the paper represents f_xsection ratio measurements of U_238 to Al_27, Na_24, Fe_56, Mn_56 * found in library QC770 N742 1992)
 
−
|-
 
−
|810 || 238U(n,f)|| Absolute ||K. Merla et al. || 91Jülich (1991) 510 || * The paper represents f_xsection ratio measurements of U_238, U_235 , Np_237, and Pu_239 for 4.45 MeV, 8.46 MeV, 18.8 MeV * very accurate description for the experiment details and through the figures and the tables * found in library QC770 N742 1992)
 
 
|-
 
|-
−
|877 ||238U(n,f) ||Absolute ||I.M. Kuks et al. ||At. Energy 30 (1971) 55 ||*measured f_xsection U_238 fission for 2.5 MeV Neutrons
+
| Open || 6879 || 900
 
|-
 
|-
−
|860 || 238U(n,f) || Absolute || N.N. Flerov et al.|| At. Energy 5 (1958) 657|| *title : antinutrino , Mean number of neutrons emitted in fission of U235 and U238 by 14-Mev neutrons, Mean number of neutrons emitted in fission of U235 and U238 by 14-Mev neutrons
+
| Close || 1 || 38
 
|}
 
|}
  
−
=Done In April (edited by 04/30/10)=
+
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.
−
1.)Testing the new laminate with random holes after applying the resistive paste on both sides. Also, the trial of applying the paste  was done, 0.1 inch brush is used for that to avoid covering the holes with the paste. the following procedure were taken:
+
 
 +
The activity  of the source is calculated based on the solid angle <math> \frac {A \times W}{4\pi} </math>
  
−
a- Voltage is applied on the the foil to check the first sparking place.
+
where '''A''' is the count per second
 +
and '''W''' is the detector solid angle.
  
−
b- Applying the paste carefully on the area between the holes with very small quantities.
+
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.
  
−
;Result:
 
  
−
a) Applying the paste shifts the sparking area to next neighboring one, so looks this will lead us to cover all the areas between the holes to kill the sparks.
+
=IAC experiment producing neutrons=
  
−
b)A need to keep the foil under voltage to keep tracking of the sparks which lead unfortunately led to loss the voltage between the two copper layers.
+
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
  
−
Even a drop of paste got stuck in one of the holes(which has low possibility since I cleaned all the paste applied very well), or the two layers are no longer isolated from each other!
+
[[File:moderator_nspect.png | 70 px]]
−
 
 
  
−
2.)Final touches on the HV-circuit are done, diagrams are done by eagle with Gerber files, the chamber is ready for redesigning.
+
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.
  
−
3.)Running Th-232 fission simulation without ionization on inca and daq1. Energies 1-9MeV (inca) and 19-22 MeV(daq1)  will be done by today(04/30/10).  
+
[[File:exp_setup.png | 70 px]]
  
−
4.)Tracking the process to get Th-232, contacting other vendors for radioactive isotopes, trying to get low cost ones.
+
=References=
  
−
= Th-232 and U-238 Activity in mCi=
 
−
General information:
 
  
−
{| border="1" cellpadding="4"
+
==THGEM design==
−
|-
+
 
−
|Physical properties || U-238  || Th-232
+
THGEM#9
−
|-
+
 
−
| Half life in years|| 4.468 X 10^9 || 1.405 X 10^10
+
[[Media:Shalem_MSthesis_march2005.pdf]]
−
|-
 
−
|Decay rate per second || 4.91 X 10^-18 || 1.56 X 10^ -18
 
−
|-
 
−
| Molar Mass g/mol || 238.02891 || 232.0381
 
−
|-
 
−
| Activity of 2 kg in mCi || 0.68 || 0.22 
 
−
|}
 
  
−
Avogadro's number is 6.0221 X 10^23 /mol
 
  
−
1 Ci = 3.7 X 10^10 disintegration/ second
+
[[Media:Raz_Alon_MSthesis_Dec2007.pdf]]
  
−
<math>2 \times 10^3 g \times \frac{1 mol}{238.03 g} \times \frac{6 \times 10^{23} atoms}{mol} \times \frac{decay}{4.4 \times 10^{9} years} \times \frac{yr}{365\times 24 \times 3600 sec} \frac{1 Ci}{3.7 \times 10^{10} decays/sec} \equiv 0.98 mCi</math>
+
==Electric field Simulation==
  
−
<math> \ Half Life \times \ Decay Rate = ln2 </math>
+
;Rim size dependence
  
 +
[[ file: THGEM_Efield_simulation.pdf]]
  
−
<math>2 \times 10^3 g \times \frac{1 mol}{238.03 g} \times \frac{6 \times 10^{23} atoms}{mol} \times \frac{ ln2\times \ decay}{4.4 \times 10^{9} years} \times \frac{yr}{365\times 24 \times 3600 sec} \frac{1 Ci}{3.7 \times 10^{10} decays/sec} \equiv 0.68 mCi</math>
 
  
−
=References=
 
  
 
;2010 THGEM design(s):
 
;2010 THGEM design(s):
Line 804: Line 852:
 
  Voss and 3 russian references for Dy(n,x) cross sections
 
  Voss and 3 russian references for Dy(n,x) cross sections
  
−
[[Media:Shalem_MSthesis_march2005.pdf]]
+
 
  
 
http://arxiv.org/abs/0903.3819 Dy photon gammas spectrum
 
http://arxiv.org/abs/0903.3819 Dy photon gammas spectrum
Line 869: Line 917:
  
 
Resistors online store : http://www.justradios.com/rescart.html
 
Resistors online store : http://www.justradios.com/rescart.html
−
 
  
 
==RETGEMs==
 
==RETGEMs==
Line 952: Line 999:
  
  
−
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TVV-46G57SW-53&_user=10&_coverDate=10%2F01%2F1991&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1388383717&_rerunOrigin=google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=c3229e061695dfa28617f9f5db1ef55d
+
[[http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TVV-46G57SW-53&_user=10&_coverDate=10%2F01%2F1991&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1388383717&_rerunOrigin=google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=c3229e061695dfa28617f9f5db1ef55d]]
  
 
http://cat.inist.fr/?aModele=afficheN&cpsidt=16864172
 
http://cat.inist.fr/?aModele=afficheN&cpsidt=16864172
Line 962: Line 1,009:
  
  
−
http://books.google.com/books?id=NRXnXmFRjWYC&pg=SA48-PA17&lpg=SA48-PA17&dq=depleted+uranium+coating&source=bl&ots=a6jHsdI6Ec&sig=zVxKGeD4E42gAVkr8Otg9bfpkyg&hl=en&ei=8FgtTIH1HMGC8gbNl-S-Aw&sa=X&oi=book_result&ct=result&resnum=6&ved=0CCoQ6AEwBThG
+
[http://books.google.com/books?id=NRXnXmFRjWYC&pg=SA48-PA17&lpg=SA48-PA17&dq=depleted+uranium+coating&source=bl&ots=a6jHsdI6Ec&sig=zVxKGeD4E42gAVkr8Otg9bfpkyg&hl=en&ei=8FgtTIH1HMGC8gbNl-S-Aw&sa=X&oi=book_result&ct=result&resnum=6&ved=0CCoQ6AEwBThG]
−
 
 
−
http://www.google.com/url?sa=t&source=web&cd=90&ved=0CDYQFjAJOFA&url=http%3A%2F%2Fwww.ga.com%2Fenergy%2Ffiles%2FIFT_Catalog.pdf&ei=RFktTPbgKYL88AbC1tSSAw&usg=AFQjCNE3VbqBWbvcKln4pJVAj8FyKfcOig
 
  
 +
[http://www.google.com/url?sa=t&source=web&cd=90&ved=0CDYQFjAJOFA&url=http%3A%2F%2Fwww.ga.com%2Fenergy%2Ffiles%2FIFT_Catalog.pdf&ei=RFktTPbgKYL88AbC1tSSAw&usg=AFQjCNE3VbqBWbvcKln4pJVAj8FyKfcOig]
  
 
;IAEA Photonuclear Data Library  [http://www-nds.iaea.org/photonuclear/]
 
;IAEA Photonuclear Data Library  [http://www-nds.iaea.org/photonuclear/]
Line 1,075: Line 1,121:
  
 
http://134.50.203.63/
 
http://134.50.203.63/
 +
 +
 +
<references/>

Latest revision as of 03:52, 2 November 2015

HM_2014

2012

2011

2010

2009

Dissertation

11/01/2015

Measurements


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


Conclusion

File:Conc.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.

QDC TDC PS-ADC setup

Peak sensing gate

GEM PS gate.png

QDC gate

GEM QDC gate.png


TDC start

TDC pulser.png


TDC STOP

TDC GEM.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:
Lost

PS l1.png

Detected


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

Updates

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


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: 

 c775CommonStop(TDC_ID);

Ionization xsections for different particles emitted from U-233

Photons

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

Ref. : http://physics.nist.gov/PhysRefData/Xcom/html/xcom1.html


Electrons

Electron ion Ar.png

Ref. :

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


Alpha Particles

Alpha ionization.png

Ref. :

http://www.exphys.jku.at/Kshells/

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

[math]S_{HLE}[/math]


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.


[math]S_{PSD}[/math]


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
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.


GEM performance data graphs


Electronics Flow Chart

IAC electronics flow chart.png


200px

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

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 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

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

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

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/ 


<references/>
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