2010 - Revision history

Abdehait: /* Resistive paste thickness-mass calibration curve */

2011-11-08T15:05:50Z

Resistive paste thickness-mass calibration curve

Abdehait: /* Simulation */

2011-04-27T13:45:12Z

Simulation

Abdehait: /* Resistive paste thickness-mass calibration curve */

2011-04-04T16:34:03Z

Resistive paste thickness-mass calibration curve

Abdehait: /* 12/15/10 */

2011-04-04T16:33:04Z

12/15/10

Abdehait: /* 12/6/10 */

2011-04-04T16:32:03Z

12/6/10

Abdehait: /* AFCRD Reports-2010 */

2011-01-03T15:23:47Z

AFCRD Reports-2010

Abdehait: /* AFCRD Reports-2010 */

2011-01-03T15:21:01Z

AFCRD Reports-2010

Abdehait: /* 12/15/10 */

2011-01-03T15:20:32Z

12/15/10

Abdehait: /* 12/15/10 */

2011-01-03T15:20:01Z

12/15/10

Abdehait: /* 12/15/10 */

2011-01-03T15:15:03Z

12/15/10

@@ Line 1,847: / Line 1,847: @@
 |  Plate Surface area (cm^2) (length <math> \pm 0.1 cm </math> )        ||  mass (g)<math> \pm 0.1mg </math> before applying the paste || mass (g)<math> \pm 0.1mg </math> after applying the paste ||<math>\frac{mg}{cm^2}</math> ||notes
 |-
-|   1X1 ||  0.2627 || 0.2634 || 0.7|| paste on both sides
+|   1.0X1.0 ||  0.2627 || 0.2634 || 0.7|| paste on both sides
 |-
-| 2X2  || 0.9776 || 0.9793  || 0.4 || paste on both sides
+| 2.0X2.0  || 0.9776 || 0.9793  || 0.4 || paste on both sides
 |-
-| 3X3   || 2.5074 || 2.5074 || 0 || paste on one side
+| 3.0X3.0   || 2.5074 || 2.5074 || 0 || paste on one side
 |-
-| 4X4   || 4.4923 || 4.4940  || || paste on one side
+| 4.0X4.0   || 4.4923 || 4.4940  || || paste on one side
 |-
-| 5X5   || 7.3261 || 7.3250 || || paste on one side (paste is not uniform)
+| 5.0X5.0   || 7.3261 || 7.3250 || || paste on one side (paste is not uniform)
 |}

@@ Line 1,027: / Line 1,027: @@
 The number of incident particles per Area = <math>\rho_{Th-232} V /A = \rho_{Th-232} L_{target} </math>
-<math>\rho_{Th-232} =  19.1 g/cm^3 </math>
+<math>\rho_{U-238} =  19.1 g/cm^3 </math>
 <math>\Rightarrow 19.1 g/cm^3  \frac{1 mol}{238.029 g}\frac{ 6.02 \times 10^{23} Atoms}{mole} = 4.83 \times 10^{22}</math>

← Older revision		Revision as of 16:34, 4 April 2011
Line 1,896:		Line 1,896:

	- New samples will be prepared, all have the 2x2 cm^2 area, with a small groove on the edge to have new images by SEM, each sample will have a cerain amount of the resistitive paste, the mass of the paste accuratlely be determined (hopefully) using a high presicion scale.		- New samples will be prepared, all have the 2x2 cm^2 area, with a small groove on the edge to have new images by SEM, each sample will have a cerain amount of the resistitive paste, the mass of the paste accuratlely be determined (hopefully) using a high presicion scale.
		+
		+	===Experiment Tasks timetable===
		+	{\| border="1" cellpadding="4"
		+	\|-
		+	\| Date \|\| Task \|\| Notes
		+	\|-
		+	\| 10/20/10 \|\| Preparing the samples in different areas \|\| Done on time
		+	\|-
		+	\| 10/21/10 \|\| painting and curing the paste, measuring the mass before and after painting the paste \|\| measuring the mass is accurate enough, even we borrow the scale and put it in table without anything around and without being moved just for the day of the taking the data or finding a more accurate one in a more stable measuring conditions.
		+	\|-
		+	\|10/22/10 \|\| studying the samples using SEM \|\| CAMAS facility across Alvin Ricken Drive from the Idaho Accelerator Center, at 11:00 AM
		+	\|-
		+	\|10/28/10 \|\| studying the 2x2 samples using SEM \|\| (postpone) CAMAS facility across Alvin Ricken Drive from the Idaho Accelerator Center, at 11:00 AM
		+	\|-
		+	\|11/4/10 \|\| studying the 2x2 samples using SEM \|\| CAMAS facility across Alvin Ricken Drive from the Idaho Accelerator Center, at 11:00 AM ??
		+	\|}

	=12/15/10=		=12/15/10=

← Older revision		Revision as of 16:33, 4 April 2011
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	[[Insulators under a high voltage]]		[[Insulators under a high voltage]]
		+
		+
		+	=RETGEM vs. THCOBRA =
		+
		+	{\| border="1" cellpadding="4"
		+	\|-
		+	\|RETGEM \|\| THCOBRA
		+	\|-
		+	\|[[File: RETGEM_design.png \|250 px]]\|\| [[File: THCOBRA_design.png \|250 px]]
		+	\|-
		+	\|[[File: RETGEM_E-field.png \|250 px]] \|\| [[File: THCOBRA_E-field.png \|250 px]]
		+	\|-
		+	\|[[File: REGEM_gain.png \|250 px]]\|\| [[File: THCOBRA_gain.png \|250 px]]
		+	\|}

	=AFCRD Reports-2010=		=AFCRD Reports-2010=

← Older revision		Revision as of 16:32, 4 April 2011
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	[[File:20_1.27_connector.jpeg \|\| 250 px]]		[[File:20_1.27_connector.jpeg \|\| 250 px]]

		+
		+	=Resistive paste thickness-mass calibration curve=
		+
		+	;Aim
		+
		+	Studying the relationship between the mass and thickness of the resistive paste painted over 10X10 HTTGEM Foil.
		+
		+	;Experiment equipments and restrictions:
		+
		+	Accurate scale (<math> \pm 0.1 g </math>), SEM (scanning electron microscope).
		+
		+	SEM sample's height limit : 5 cm.
		+
		+	(Dr. David Peterson Assistant Professor in Anthropology,Research Scientist, Center for Archaeology, Materials and Applied Spectroscopy (CAMAS) , 157 Graveley Hall,Idaho State University)
		+
		+
		+	;Procedure:
		+
		+	Measuring the mass of Prepared samples of 0.5 thickness FR4 square plates with different surface areas as in the table below before and after painting the paste.
		+
		+	Studying the paste distribution and thickness under SEM.
		+
		+	;Experimental Data
		+
		+	{\| border="1" cellpadding="4"
		+	\|-
		+	\| Plate Surface area (cm^2) (length <math> \pm 0.1 cm </math> ) \|\| mass (g)<math> \pm 0.1mg </math> before applying the paste \|\| mass (g)<math> \pm 0.1mg </math> after applying the paste \|\|<math>\frac{mg}{cm^2}</math> \|\|notes
		+	\|-
		+	\| 1X1 \|\| 0.2627 \|\| 0.2634 \|\| 0.7\|\| paste on both sides
		+	\|-
		+	\| 2X2 \|\| 0.9776 \|\| 0.9793 \|\| 0.4 \|\| paste on both sides
		+	\|-
		+	\| 3X3 \|\| 2.5074 \|\| 2.5074 \|\| 0 \|\| paste on one side
		+	\|-
		+	\| 4X4 \|\| 4.4923 \|\| 4.4940 \|\| \|\| paste on one side
		+	\|-
		+	\| 5X5 \|\| 7.3261 \|\| 7.3250 \|\| \|\| paste on one side (paste is not uniform)
		+	\|}
		+
		+
		+
		+	;SEM Images
		+
		+	;2x2 sample
		+
		+	{\| border="1" cellpadding="4"
		+	\| Image(a) \|\|Image(b) \|\|Image(c) \|\|
		+	\|-
		+	\|[[File: 2X2.png \|250 px]]\|\| [[File: 2X2_scale.png \|250 px]] \|\| [[File: 2X2_scale_zoom.png \|250 px]]
		+	\|}
		+
		+
		+
		+	;4x4 sample
		+
		+	{\| border="1" cellpadding="4"
		+	\|Image(1) \|\|Image(2) \|\|Image(3) \|\|Image(4) \|\|Image(5)
		+	\|-
		+	\|[[File: 4x4.png \|250 px]]\|\| [[File: 4X4_scale.png \|250 px]] \|\| [[File: 4X4_scale_zoom.png \|250 px]] \|\| [[File: 4X4_3scale_zoom_001.png \|250 px]] \|\| [[File: 4X4_scale_zoom_002.png \|250 px]]
		+	\|}
		+
		+
		+
		+
		+	;Conclusions and Next step(s)
		+
		+	-Using SEM is accurate enough to measure the paste thickness within few micros depending on the HFW (horixzontal field width) value (determined for each image).
		+
		+	- Highly recommended to use a high precision scale for measuring the mass variation accurately for each samples, not only for this experiment but also for the future samples that will contain a radioactive materials.
		+
		+	- Preferable size for the best image is 2x2 cm with clean edges and reference line.
		+
		+	- The resistive paste thickness changes from one sample to another and is not unform surface within the micrometer scale, for the 4x4 sample maxmimum value measured or the paste thickness was 120 um, and the minimum was 80 um. Successivly, the 2x2 sample paste thickness was measured with a maximum of 66.84 um and mimimum 49.17 um.
		+
		+	- The measurements were accurate whenever the paste is distiguished from the over flow of the paste on the edge, and as the charging on the sample is the least. (When the sample was inside the SEM-chamber, a beam of electrons hit the sample and created charged areas that soemtimes ddi not make the edge image sharp enough, this is clear by comparing image (4) and image (5)).
		+
		+	- New samples will be prepared, all have the 2x2 cm^2 area, with a small groove on the edge to have new images by SEM, each sample will have a cerain amount of the resistitive paste, the mass of the paste accuratlely be determined (hopefully) using a high presicion scale.

	=12/15/10=		=12/15/10=

← Older revision		Revision as of 15:23, 3 January 2011
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	* Improving the read out system by adding a VFAT adapter card.		* Improving the read out system by adding a VFAT adapter card.
		+
		+	=References=
		+
		+	[https://wiki.iac.isu.edu/index.php/Neutron_TGEM_Detector_Abdel#References]

	[https://wiki.iac.isu.edu/index.php/Neutron_TGEM_Detector_Abdel Go back]		[https://wiki.iac.isu.edu/index.php/Neutron_TGEM_Detector_Abdel Go back]

← Older revision		Revision as of 15:21, 3 January 2011
Line 1,895:		Line 1,895:

	* Improving the read out system by adding a VFAT adapter card.		* Improving the read out system by adding a VFAT adapter card.
		+
		+	[https://wiki.iac.isu.edu/index.php/Neutron_TGEM_Detector_Abdel Go back]

← Older revision		Revision as of 15:20, 3 January 2011
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	[[Insulators under a high voltage]]		[[Insulators under a high voltage]]
−
−
−	~~[https://wiki.iac.isu.edu/index.php/Neutron_TGEM_Detector_Abdel Go back]~~
−

	=AFCRD Reports-2010=		=AFCRD Reports-2010=

← Older revision		Revision as of 15:20, 3 January 2011
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	[https://wiki.iac.isu.edu/index.php/Neutron_TGEM_Detector_Abdel Go back]		[https://wiki.iac.isu.edu/index.php/Neutron_TGEM_Detector_Abdel Go back]
		+
		+
		+	=AFCRD Reports-2010=
		+
		+	; Done in June (edited by 07/09/10)
		+
		+	1.)The design for the THGEM-HV circuit is submitted to the board house.
		+
		+	2.) Preparing the lab for a making samples and testing the THGEM foil. Preparation includes fixing the milling machine, and finding a vendor to provide the FR4 of thickness 1 mm, coated with 17 um copper from both sides. the size of the plate should be minimum 11X 11cm to fit the inside of THGEM-detector.
		+
		+	3.) Finding a vendor to make THGEM foil : making 0.5 mm holes in certain pattern described in a CAD-file.
		+
		+	4.) One of THGEM-foil is going to be covered by Th-232, a sample of Cerium (an stable element from the same group has close to TH-232 in physical properites) was used to test the mixing process with the paste.
		+
		+	5.) Running the simulation using GEANT4 to calculate the fission cross for Th-232.
		+
		+	6.) U-238 is going to be provided, it is going to be mixed with paste as in the same procedure done by Cerium to compare the detector characteristics with one based on Th-232.
		+
		+	7.) Practicing repairing process for GEM-detector with Tamar.
		+	;Results:
		+
		+	a.) Improving the design of PC-board to hold up a voltage up to 10 kV without any sparking or short, also to include Geiger-mode APD circuit part if the idea get approved.
		+
		+	[[File:Direct observation of avalanche scintillations in a THGEM-based two-phase Ar avalanche detector using Geiger-mode APD.pdf]]
		+
		+
		+	b.) The milling machine was sent to a repair shop in Boise, expected to start working by the end of next week from the date above.
		+
		+	c.) Still looking for a vendor to provide copper double clad FR4 with the same properties mentioned above.
		+
		+	d.)We got a Quote from a vendor to THGEM-foil but still we are waiting another two of them to compare, also checking if the vendor is able to deal with ones that has the radioactive materials.
		+
		+	e.) Simulation using GEANt4 needs to be improved compared with the experimental fission cross section provided by ENDF-data by creating a new ENDF-file to be a reference for GEANT4 for the Th-232 fission cross.
		+
		+	f.) To avoid accumulation of radioactive wastes, Nd (a stable element from the same group of U-238) will be mixed with the paste.
		+
		+	g.) Simulation for U-238 fission cross section started by 12 MeV energy and gave a 0.7b .
		+
		+	h.) Practicing on GEM gave an idea about required steps to finish THGEM-detector.
		+
		+	;June
		+
		+	*Uranium Oxide has been chosen to dope the THGEM detector's resistive paste. Procedures are being developed to apply the dopant.
		+	*A HV distribution board has been designed for the detector and will be procured by the end of July.
		+	*The THGEM detector's ionization vessel has been machined to accommodate the above HV board.
		+
		+	;Done in July (edited by 07/09/10)
		+
		+	A GEANT4 simulation of the 232Th(n,f) cross section from threshold to 20 MeV showed an increase with incident neutron energy but under-predicted the experimental results by a factor of 3 when the incident neutron energy was below 7 MeV. A simulation of 238U(n,f) under-predicted experiment by a factor of 2 for neutron energies below 5 MeV but was consistent with experiment above 5 MeV.
		+
		+	;July
		+
		+	*A HV distribution board has been constructed and tested to sustain high voltages up to 9 kV.
		+	*5 FR4 boards have been etched. Three boards were coated with resistive paste without dopant. 4 boards have been sent out for machining the 100 precision holes for preamplification.
		+
		+
		+
		+	;August
		+
		+	*A set of 20 holes were machined in one of the FR4 boards etched last month in order to test for HV breakdown while waiting for the remaining FR4 boards to be machined by a vendor.
		+	*A HV test of the above board showed a voltage breakdown at 2800 Volts when the board is immersed the detectors Argon C02 ionization gas. Other groups have shown that a high voltage of 1550 Volts was sufficient to operate similar detectors. The changes made to the board for this project should not impact the HV specification of 1550 Volts. The additional Voltage which is possible with our boards will serve to increase the detector gain.
		+
		+	;September & October
		+
		+	*A set of 100 holes have been machined in each of the 5, 10X10 cm FR4 plates by the vendor.
		+	*A test of the separation distance between the amplification board and grounded readout plane indicates that a distance of 2 mm is possible without discharges.
		+	*The amplification stages need to be combined into a stack, tests are underway to determine the optimal separation distance between each amplification card in the stack.
		+
		+	;November
		+
		+	* Detector amplification factors was studied, two Coated FR4 plates were placed to test the voltage applied on each plate and the distance between the FR4 plates, the aim was to get 2 kV between the top and the bottom of the FR4 plate Ar/Co2 gas. Until this point we are achieving about 1.7 kV in Ar/Co2 gas, 2.5 mm is the least distance between the plates.
		+
		+	* Improving the read out system by adding a VFAT adapter card.

← Older revision		Revision as of 15:15, 3 January 2011
Line 1,823:		Line 1,823:

	[[Insulators under a high voltage]]		[[Insulators under a high voltage]]
		+
		+
		+	[https://wiki.iac.isu.edu/index.php/Neutron_TGEM_Detector_Abdel Go back]