Neutron TGEM Detector Abdel
Haithem's logbook for developing neutron sensitive TGEM detector
Documentation
1/23/09
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1.) Search the web for patent which coats GEM detector with neutron sensitive materials. I think it is for Thermal neutrons.
Materials of high neutron capture cross section are studied widely, an example is the following patent
[[1]]
Most of the high neutron capture cross section materials were measured for different neutron energies. A comprehensive work is published in 2000. The project was supported by Korea Atomic Energy Research Institute and Brookhaven National Laboratory [[2]]
U-235 is the one of the best choices since it has a high neutron fission cross section and a long half life compared to other the other isotopes that may come under choice.
A second choice is Th-238 and U-238 which have fission cross section less than that of U-235 but still good for our experiment.[[3]]
A boron coated GEM foil is being made by the company below http://n-cdt.com/
Another method uses BF3.
We are interested in a fissionable material coated onto the copper foils that is thin enough to allow the fission fragments to escape the foil and ionize the gas in the detector.
2.) Search for companies which use either sputtering or coating technology to apply the above material to caopper PCboards with hole int them such that the material does not fill up the hole. Hole diameter = ?
The material sputter onto the copper would have thickness on the order of Angstroms.
The TGEM PCboard would have a surface area of 10 cm x 10 cm.
3.) Current neutron efficiency plots for several detector
Media:NeutronDetectionEfficiency-vs-Energy_Ne-213_BaF.pdf
1/30/09
1.) Investigate if Thorium Oxide will be a good candidate for the fission chamber. You would use electrolysis to coat a TGEM board.
Ways to make thorium fission chamber
2.) Find reference for THGEM9, this was used to determine optimal THGEM design 2 years ago
GEM-copper plate has dimensions of 3X3cm or 10X10cm with thinkness 5 micrometer copper layers.It has holes with diameter 60-80 micrometer.(From Operation of a triple GEM detector with CsI photocathode in pure BF4)
2/6/09
Thin deposition ThO2 molecular plating
2/13/09
Check if the people below can deliver Th coated Al or Cu sheets , coating thickness smaller than 5 micron, the thinner the better. http://www-wnt.gsi.de/tasca/
2/20/09
2.5 x 2.5 cm thorium coated TGEM cards coated by ISU chemistry.
chemistry Department cant not do the sputtering for safety purposes, they like to avoid radiation contamination.
Need a mask for the predrilled TGEM cards to prevent Thorium from entering holes
Radioactive waste procedure if we are allowed to sputter in chemistry.
Write report describing the process we want to do.
Radioactiving of Thorium may be a stumbling blog because of waste generated.
If we go for non-radioactive materials look up fission X-sect for Bismuth and Dysprosium
Fission cross section for Bi starts to be effective when the neutron energy is more than the range of interest.
Dy-isotopes are very good for absorbing neutrons in the range between 0.01- 10 MeV.
Media:Zaidi_RadChem_vol93_2005.pdf
2/27/09
1.) Dysprosium (Dy) makes a lot of gammas and maybe 100 less alphas
2.) Don't give up trying to make thorium coated materials
try to send e-mail to one of these authors
N. Takahashi, Zeitschrift für Physik A Hadrons and Nuclei Volume 353, Number 1 / March, 1995
3.) Fission cross-section n,f for Tb
3/13/09
1.) look for a company that does resistive evaporative coatings
This company sells the machine http://www.lesker.com/newweb/Deposition_Sources/ThermalEvaporationSources_Resistive.cfm
2.)(n,f) X-sect for Dysprosium (Dy) ?
3.) Thorium and thorium oxide thin films (19 to 61 nm thick) were RF-sputtered onto mirrors. RF sputtering onto copper plates?
The neutron fission cross sections of 92235U and 92238U between 0.3 and 12.5 MeV W W Osterhage et al 1978 J. Phys. G: Nucl. Phys. 4 587-595
http://www.inf.uu.se/Reports/publications.html
Neutron-induced fission cross sections of natPb and 197Au in the 45-180 MeV region, V.P. Eismont, A.V. Prokofiev, A.N. Smirnov, S.M. Soloviev, H. Condé, K. Elmgren, N. Olsson and P.-U. Renberg Conference Proc. ADTTA99, 1999, (in press).
Up-to-date status and problems of the experimental nucleon-induced fission cross section data base at intermediate energies, V.P. Eismont, A.V. Prokofiev, A.N. Smirnov, I.V. Ryzhov, G.A. Tutin, H. Cond, K. Elmgren, N. Olsson and P.-U. Renberg, Proc. ADTTA99, 1999, (in press).
Neutron-induced fission cross section ratios of 209Bi and 238U at 75 and 96 MeV, V.P. Eismont, A.V. Kireev, I.V. Ryzhov, S.M. Soloviev, G.A. Tutin, H. Condé, K. Elmgren, N. Olsson and P.-U. Renberg, Proc. ADTTA99, 1999, (in press).
Neutron-induced fission fragment angular distribution of 238U at 96 MeV, V.P. Eismont, A.V. Kireev, I.V. Ryzhov, S.M. Soloviev, G.A. Tutin, H. Condé, K. Elmgren, N. Olsson and P.-U. Renberg Proc. ADTTA99, 1999, (in press).
Measurements of neutron-induced fission cross sections of heavy nuclei in the intermediate energy region, V.P. Eismont, A.V. Prokofyev, A.N. Smirnov, K. Elmgren, J. Blomgren, H. Condé, J. Nilsson, N. Olsson and E. Ramström, Accelerator-Driven Transmutation Technologies and Applications, Kalmar, ed. H. Condé (Uppsala: Uppsala University, 1997) p 606-612.
4/2/09
Summury of events through the last two weeks:
1- Looking for a neutron fission cross section for Dyspromium. 2- Looking for other possile elements that can be sued beside our choices for Thorium and Dysprosium. these elemets should have a high neutron cross for fission (n,f),(n,gamma),(n,p) or (n,alpha).
3- Using Neutrons cross sections (by D. Hughes and R. Schwartz, 2nd edition, 1957) as comphensive reference for our choice.
Comparison between Thorium and Dysprosium
.
Thorium: chacterized by relatively high neutron fission cross for both of its isotopes (Th-232 nad Th-230) compared to the stable elements but it is one of low fission cross sections compared to radioctive actinides. A lot of efforts are spent even in coating or finding the appropriate place or group to do that, since most of people are totally disencouraged to coat radioctive elements.
Dysprosium: radioactively stable,it has 5 isotopes Dy-160, 161, 162, 163 and 164. It is one of the best elements for detecting the neutrons because of high neutron capture cross section in the energy range of interest.
Also dysprosium pulls out alpha paticles (σ(n,α)= 3.6 mb at 14.2 MeV).
Other Possible Elements
. Generally,the highest values for neutron cross sections (σ(n,f), σ(n,p), σ(n,γ) and σ(n,α)) are for radioactive isotopes, which are not desirable for coating. Fortunately, there are non- radioactive elements have a relatively high neutron cross sections, for example:
σ(n,γ) at 0.025 MeV (in mb): Gd-158(710(70)), Sm-152 (670(100)), Br-81 (550(55)), Sm-154 (530(70)), Ce-142 (425(45)),
Hf-180(440(70)), Ru-96(320(60)), Ru-102 (390(40)), W-186 (300(40)), Zr-96 (240(40)), Hg-202(57(13))
σ(n,γ) at 1 MeV (in mb): Re-185(180), (390(40)), Ru-102 (30), Ru-104 (31), Hg-204(100), Br-81 (17)
σ(n,γ) at 14.5 MeV (in mb): Gd-160 (19(5)), Zr-96 (<4),
Element | X-sect (mb) |
Re-185 | 180 |
Ru-102 | 390 |
4/3/09
1.) Derive equations for voltages at each GEM stage and the net current for our voltage network and check them with measured values for the 4kV version of the voltage network.
2.) Reference [J.C. hadler, Radiation Measurements Vol 43 (2008) pf S334-S336] says
- R = 14 \mu m = mean range of fission fragment6s in U_3 O_8
- R= 12 um for UO_3
- 0.1 um thickness U( Th) will reduce mean length of fission tracks by 2%
3.) Plot N -vs- d using Equation 2 of Reference [J.C. hadler, Radiation Measurements Vol 43 (2008) pf S334 The number of particles per unit area is given by the equation:
d : the thickness in (um)
The range of the fragments in the emulsion is 12.07 um
4/17/09
A call conference with Dr.Wolfe, As result, the following is considered as next step for the project:
1- Check the melting temperature that a PC boeard can hold ( the size of the chamber can hold the 10 X 10 PC board ). The experiment is done, the temperature in average was aroubd 305oC, the PC board can hold that temperature easily,
the PC board was just burned since the medium around is O2, but there is one thing I want ot be sure of, if the PC board has a very light layer of certain material covers its surface and can't hold up that temeperature?
An experiment is done today (4/30/09) to check the PC board behavior at 350oC. A peace of copper sticked by normal used glue.
PC boeard can't hold up the temperature 350oC.
2- Checking from a vender for chunk bulk ThF4 with size min. 30 cc.
3- Checking the thermal properties of ThF4 specially the melting point and if Thorium is adhere to copper in that temperature.
4- A mask should be prepared from stainless steal (Al is not preferable),inaddtion to thinking of drilling process and who is going to do it.
Laser machining can cut 1" stainless steel sheets
5- Dr. Forest is going to send the email after collecting all the information needed to Dr. Wolfe.
Coaing process is going to be by electron beam, thorium should be heated to 1750 C. (the melting point for pure Th).
Until this point the uniformity of the surface is not an important factor, but I think it would be important whenever we start thinking of the track and the direction for Th fission fragments.
4/23/09
1- Check the melting temperature that a PC board can hold ( the size of the chamber can hold the 10 X 10 PC board ).
Basically FR-4, FR-1, CEM-1 or CEM-3 PCB are made of polytetrafluoroethylene which has (327 °C (620.6 °F))as a melting point.
The experiment is done, the temperature in average was around 305 °C, the PC board can hold that temperature easily,the PC board was just burned since the medium contains O2, but there is one thing I want to be sure of, if the PC board has a very light layer of certain material covers its surface?
2- Checking from a vender for chunk bulk ThF4 with size min. 30 cc.
http://www.element-collection.com/RGB_Elements_OCT04_rev05.pdf
Element-collection sells thorium with 190$/gram !
3- Will Thorium adhere to copper
Thorium flouride is used for optical purposes, according the technical applications they have a number of recommendations related to sputtering by E-beam, and other materials that helps in thorium flouride adhesion.[4]
Looks there is a little change, Dr. Forest is going to check a vendor for U-238, which has a better fission cross section (3 times higher compared to Th-232),in addition to , the high price for Th-232 and risk of having flakes after sputtering, Throium by itself does not adhere with the surfaces unless other materials are used through the sputtering process (as methioned in the case of coating glass with thorium fluoride).
5/1/09
1.) Results from PCboard heating test: Board melts at 350 but not 310 degrees Celcius (Documents suggest 327 as the melting point.)
Before heating to 350 | After Heating to 350 |
Before heating to 298 | After Heating to 298 |
The experiment is done on the PC-board, it was heated for an hour under 298°C. The result is shown by the second photo, looks that PC-board should be replaced by another material that can hold this temeperature for longer time.
2.) Oak Ridge will give us 1 kg of metal Th-232. We pay for shipping and we need to do rad licenses. Dr. Forest e-mail Dr. Brey and the paper work is beginning.
Contact info
Lloyd J. Jollay Manager Nuclear Technology and Nonproliferation Y-12 National Security Complex P.O. Box 2009 Oak Ridge, TN 37831-8112 Office: 865-241-1872 Fax: 865-574-5169 Pager: 865-873-9146 Mobile: 865-206-9663
3.) Laser cutting can do up to 1" thick stainless steel sheets, we can make a mask! Need to learn CAD to create a drawing of the mask which will be uploaded to the laser cutting machine. make tolerances around 500 micron (1/2 mm).
Insert picture of our GEM PC board with a table of distances.
4.) Meting Point for U-238 =?
Melting Point: 1408 K (1135°C or 2075°F). Boiling Point: 4404 K (4131°C or 7468°F)
5/8/09
1.) It appears the FR-7 melts at 220 celsius so we may not be able to coat copper clad FR4 with U-28 or Th-232. This means we will most likely coat a copper sheet which is attached to a frame for tension and then laminate FR4 after we have coated the copper sheet with U-28 or The-232.
Determine melting point of our current PC boards.
Melting point for the PC board is 260 degrees Celsius,within this degree a change took place in the shape of the board which will make the possibility to use it for sputtering process is very little, the color of the PC-board starts to change at 200 degrees Celsius.
200 | 210 | 260 |
, |
2.) The distance between holes in the TGEM appear to be 1mm. A laser can cut through 1" of stainless steel. What accuracy can the laser have when cutting through the thinnest available SS we want to use for a mask.
Find laser resolution (200 microns?)
The following company [5] can reach to a tolerance of 10 micrometer if the thickness of the plate is bigger than 300 micrometer, in our case the thickness of copper foil is 45 micrometer, and the hole is diameter is 1 mm, a tolerance of 200 micrometer is going to be good for the drilling the holes and doing the mask. an email from the company will confirm the expectations.
Determine thinnest SS mask
still waiting for the email.
3.) HV distribution chain calculation. Low voltage version?
Order resistors based on power calculation, work with Tumuna on the order.
4.) Install GEANT4 in your Inca account, Start GEANT4 Fission model (CHIPS or GEISHA).
5/15/09
1.) Insert picture of PCboard at 220 and 260 and denote time spent at that temperature.
2.) The distance between holes in the TGEM appear to be 1mm and are staggered between rows. A laser can cut through 1" of stainless steel. We would like a laser with position accuracy to at least 100 microns (4 mils :1000 mils = 1 in) which can drill a hole whose diameter is accurate to 4 mils. What accuracy can the laser have when cutting through the thinnest available SS we want to use for a mask.
Find laser resolution (10 microns?)
Determine thinnest SS mask
3.) HV distribution chain calculation. Low voltage version?
Look at the following diagram :Media:GEM_HV_circuit.ps
Order resistors based on power calculation, work with Tumuna on the order
4.)GEANT4 is installed in Inca account, ExampleN02 was compiled and runs.
Add GEANT4 Fission model (CHIPS or GEISHA) to ExampleN02 program. Goal is to find a model which reproduces the X-section data for Th-232 above.
5/22/09
1.) heat PC board for 3 hours at 210C
2.) Determine laser resolution for a 45 micron thick copper sheet
3.) HV distribution chain calculation. Do a sample calculation for
=?4.) Going to order 25 resisters of each Ohm setting. Prepare a HV board for stuffing and assemble after resistors arrive.
5.)Add GEANT4 Fission model (CHIPS or GEISHA) to ExampleN02 program. Goal is to find a model which reproduces the X-section data for Th-232 above.
6/9/09
1.) Write a brief description ( 2 paragraphs) of the experimental objectives and methods with justification for the specific radionuclides and quantities.
We propose constructing a fission chamber which contains copper PCboards coated with U-238 and Th-232. Our goal is to construct a fast neutron detector. A safe in the LDS will serve as a repository for the U-238 and Th-232 bulk material. A small fraction of the material (100 g) will be sent to a collaborator at another University who will use Electron Beam-Physical Vapor Deposition to coat a 10 cm x 10 cm PCboard with U-28 or Th-232. The radioactive material will be a 5 micron or less coating attached to the PCboard. The PCboard will reside inside a gaseous detector. The quantities of each bulk material are given in the table below. Oak Ridge national Lab will supply 1kg of Th-232 at no cost. Unfortunately, 1kg is the smallest size available.
U-238 | Th-232 |
200 g | 1000 g |
U-238 has a atomic number 92, and mass number of 238.050785, it is mainly an alpha emitter. Th-232 has a atomic number 90, and mass number of 232.038051 , it is also an alpha emitter.
2) Describe the facility used to store the materials, diagram of room layout. location of safe.
A floorplan of the Laboratory for Detector Science is shown below.
Media:LDS dimension Model(1).pdf
The LDS has 2 safes available for storing radioactive materials. A solid steel safe manufactured by Bunker Hill with the outer dimensions of (25 cm)H X (35 cm) W X (25 cm) D and inner dimensions of 9-1/2” H X 13-1/2” W X 9-5/8” is controlled by a digital lock. The safe itself weighs 15 kg and is mounted to a wall in the LDS. A second iron safe, manufacturer unkown, uses a combination lock and has the outer dimensions of 62 H X57 W X 45 (cm)D.
3.) Describe radiation survey instruments available for monitoring.
We ask that the TSO provide us with all necessary monitoring devices.
4.) Description and estimate of radioactive waste being generated.
We do not expect to generate radioactive was.
6/12/09
1.) heat PC board for 3 hours at 210C
210 |
2.) Determine laser resolution for a 45 micron thick copper sheet
50 micron
3.) HV distribution chain calculation. Do a sample calculation for =?
resisters have arrived currently soldering ready to measure HVs (remember, Digital voltmeter has 1 kV max)
4.)Add GEANT4 Fission model (CHIPS or GEISHA) to ExampleN02 program. Goal is to find a model which reproduces the X-section data for Th-232 above.
6/19/09
1.) Th-232 mask due July 1,2009
2.) HV distribution chain calculation. Do a sample calculation for =?
3.)Add GEANT4 Fission model (CHIPS or GEISHA) to ExampleN02 program. Goal is to find a model which reproduces the X-section data for Th-232 above.
6/30/09
1.) Th-232 mask due July 1,2009
change design to be a series of lines covering the holes. Calculate the % area of the foil to be covered with Th-232.
2.) Insert HV distribution chain measurements in table form and compare to calculation.
Input Voltage = 1000 V
Current | measured | calculated |
(uA) | 262.3 | 220.7 |
From the figure above:
3.)Add GEANT4 Fission model (CHIPS or GEISHA) to ExampleN02 program. Goal is to find a model which reproduces the X-section data for Th-232 above.
Contact F.W. Jones, TRIUMF, 03-DEC-96 and ask for suggestion on simulating Th-232 (n,f) in GEANT4. Which model to get X-sections right?
F.W. Jones sent by July, 7:
G4LFission is based on the GHEISHA model of fission, by H. Fesefeldt, from GEANT 3.21.
It is a parameterized model using empirical formulas, e.g. the one for average number of neutrons. The photofission part of the model is not implemented.
My role in this was mainly as a code translator, so unfortunately I can't give you an expert opinion on it. I would suggest that for your study, use one of the prepared physics lists which will include the optimal treatments of fission for various applications.
See e.g. http://geant4.cern.ch/support/proc_mod_catalog/physics_lists/referencePL.shtml
If you are in doubt about choosing a physics list, I would strongly recommend that you post a query on the Geant4 forums, describing your application and what you wish to study (indicate if you wish to study nuclear fragments or other yields).
The forum for hadronic physics is here:
http://hypernews.slac.stanford.edu/HyperNews/geant4/get/hadronprocess.html
This forum is monitored by experts who will be able to provide a more definitive answer.
Best regards, Fred Jones
7/10/09
1.) Th-232 mask due July 1,2009
Making the lines as wide as the holes consumes 50% of the surface area.
A 0.45 mm diameter circle covering the holes and connected by 0.3 mm thick lines will increase the area available for fissionable material to 64%.
Decision is to create a series of lines 0.4 mm thick to cover the holes and connect them with support material.
We need a design of lines 0.4 mm thick covering the holes and connecting them. The distance between line should be 0.3 mm and have a tolerance of 0.1 mm. This will be an effective area of 3/7 = 42% for fission material.
2.) Insert HV distribution chain measurements in table form and compare to calculation.
Redo with actual measured resistance values
3.)Add GEANT4 Fission model (CHIPS or GEISHA) to ExampleN02 program. Goal is to find a model which reproduces the X-section data for Th-232 above.
Install model suggested by Forum below for U-232:
http://hypernews.slac.stanford.edu/HyperNews/geant4/get/hadronprocess.html
add the functions below to the physicslist. these are the fission models
G4HadronFissionProcess* Fission = new G4HadronFissionProcess();
G4ParaFissionModel* FissionModel = new G4ParaFissionModel(); thenFission->RegisterMe(FissionModel); pManager->AddDiscreteProcess(Fission);
install this into detector construction
// U-235 a = 235.01*g/mole; density = 19.050*g/cm3; U235 = new G4Material(name="U235", z= 92., a, density);
4.) Resistive Coating links
http://www.ellsworth.com/conformal.html?tab=Products
7/15/09
Got LLNL fission model with reference below
http://nuclear.llnl.gov/simulation/fission_usermanual.pdf
Created FissLib model in ExN02 using Uranium target.
The command below will turn on tracking printout
/tracking/verbose 1
The command below will send another neutron projectil in /run/beamOn 1
7/24/09
1.) Th-232 mask due July 1,2009
Add alignment holes.
File:Copper foil 04 straight lines with adjustment.pdf
2.) Insert HV distribution chain measurements in table form and compare to calculation.
Redo with actual measured resistance values
Voltage (V) | measured | calculated |
165 | 126.6 | |
98.6 | 103.4 | |
81.5 | 95.9 |
3.)Add GEANT4 Fission model (CHIPS or GEISHA) to ExampleN02 program. Goal is to find a model which reproduces the X-section data for Th-232 above.
trying to simulate the experiment by geant4, once when the source is thorium and another when the source is uranium by hitting the target every time with 10^7 neutrons of energy of 7.5 MeV.
The result :
Until now I did not see any effect of fission processes, the thickness of the target is 0.01 cm. then I should make the target thinner.
I read the paper uploaded to the wiki, the editor explained that G4NDL3.10 has limaitions, under geant4 it just has data for U 7 isotopes.
Mostly all what I got in my simulation is gamma, pair production and Compton scattering.
I did search to see who is interested in tracking fission fragment: I found the following contact with "Michael Heffner" in Lawrence Livermore National Lab. who was engaged in tracking hte fission fragment for Cf-239 but unfortunately I did not get a reply for my email:
I am working on tracking the fission fragment of thorium-232 and uranium-238, part of my work is to use Geant4 for experiment simulations, I read about your work in tracking the fission fragment of Pu-239 (n,f). which model did you use for fission fragment tracking?
the link for their work is :
http://74.125.155.132/searchq=cache:SrXOI60kSs0J:www.nscl.msu.edu/~bickley/TPCWorkshop/Presentations/03_Heffner.pdf+tracking+fission+fragment+"Michael+Heffner"&cd=1&hl=en&ct=clnk&gl=us
Use Uranium target use http://wiki.iac.isu.edu/index.php/Simulations_of_Particle_Interactions_with_Matter#Changing_the_Random_number_seed_in_GEANT4 to save random number generator state for a fission event. decrease target thickness until you see fission fragments
ExampleN02Detector construction.cc is edited, experiment simulated with 6.5 MeV neutron beam but different target thicknesses, the result is summarized as the following :
7/27/09
Zoom into interaction point to see all the particles (gamma and neutron). You will need to do this to see fission fragments anyway.
Beam Energy (MeV) | Target thickness (um) | the first fission event random number | image |
6.5 | 100 | 7458 | |
6.5 | 10 | 17475 | |
6.5 | 2 | 285078 | 100 px |
6.5 | 1 | 2,691,504 |
We can track the ions coming out of the fission process by defining the adding G4DiffuseElastic.cc to our physics list.
http://docs.google.com/gview?a=v&q=cache:hsRwLvrsdZMJ:www.oro.doe.gov/riaseb/wrkshop2003/papers/p-2-0-6.pdf+geant4+and+"+tracking+ions"+code&hl=en&gl=us&pli=1
8/3/09
1.) Th-232 mask due July 1,2009
Add alignment holes.
File:Copper foil 04 straight lines with adjustment.pdf
Need to calculate gravitation deflection of stainless steel strip that is 0.4 mm and 11 cm long wide as a function of its thickness.
Plot mask thickness -vs- deflection due to gravity.
2.) Insert HV distribution chain measurements in table form and compare to calculation.
What is uncertainty in the current used to calculate the expected voltage drop.
Voltage (V) | measured | calculated |
165 | 126.6 | |
98.6 | 103.4 | |
81.5 | 95.9 |
3.)Add GEANT4 Fission model (CHIPS or GEISHA) to ExampleN02 program. Goal is to find a model which reproduces the X-section data for Th-232 above.
- Goal
- Simulate the fission process using an incident neutron of energy 6.5 MeV and a layer of U-238 using Geant4.
- Status
- We are now seeing fission events for 1 micron thick sheets of U-238.
- We do not see fission fragments yet
Suggestions:
1.) Move target to center of world and zoom in
2.) Add particle definition of ions
3.) add G4DiffuseElastic.cc process for charged pariticles > 0
8/10/09
1.)Need to calculate gravitation deflection of stainless steel strip that is 0.4 mm and 14 cm long wide as a function of its thickness.
Plot mask thickness -vs- deflection due to gravity.
Maximum deflection of plate of a uniform load, is given by the following formula:[6]
;
where:
: Deflection (m)
w : The weight of the plate per unit length (N/m)
b : The shorter side of the plate (m) (b = 0.4 mm)
E : Young Modulus (N/m^2) (for stainless steel = 200 GN/m^2)
h : The thickness of the plate (m)
L : The length of the plate (m) (d = 0.14 m)
I : The moment of inertia (m^4)
t (m) | y_{max} (m) |
1.00 10^-7 | 0.00003150 |
2.00 *10^-7 | 0.00000394 |
3.00 *10^-7 | 0.00000117 |
4.00 *10^-7 | 0.00000049 |
5.00 *10^-7 | 0.00000025 |
1.00 *10^-6 | 0.000000032 |
2.00 *10^-6 | 0.000000004 |
2.) What is uncertainty in the current used to calculate the expected voltage drop.
measured (Mohm) | theoretical value (Mohm) | Voltage (V)measured | Voltage (V) calculated | |
0.56 | 0.010.55 | 165 | 1126.6 | |
0.47 | 0.46 | 98.6 | 103.4 | |
0.42 | 0.41 | 81.5 | 95.9 | |
0.56 | 0.55 | 244 | 220 | |
0.47 | 0.46 | 200 | 220 | |
0.42 | 0.41 | 212 | 220 |
the uncertainty in measuring the voltage is +_ 10, and for measuring the resistance is +_ 0.05 So the uncertainty in current theoritically is
3.)
- Goal
- Simulate the fission process using an incident neutron of energy 6.5 MeV and a layer of U-238 using Geant4.
- Status
- We are now seeing fission events for 1 micron thick sheets of U-2const
- We do not see fission fragments yet
- Suggestions
1.) Move target to center of world and zoom in
2.) Add particle definition of ions
3.) add G4DiffuseElastic.cc process for charged pariticles > 0
Uranium238 = new G4Isotope(name="U238", iz=92, n=238, a=238.03*g/mole);
G4IonTable *theIonTable = G4ParticleTable::GetParticleTable()->GetIonTable(); G4RadioactiveDecay* theRadioactiveDecay = new G4RadioactiveDecay(); for (G4int i=0; i<theIonTable->Entries(); i++) { G4String particleName = theIonTable->GetParticle(i)->GetParticleName(); if (particleName == "GenericIon") { G4ProcessManager* pmanager = theIonTable->GetParticle(i)->GetProcessManager(); pmanager->AddProcess(theRadioactiveDecay); } // ions G4Deuteron::Deuteron(); G4Triton::Triton(); G4He3::He3(); G4Alpha::Alpha(); G4GenericIon::GenericIonDefinition(); } else if (particleName == "alpha" || particleName == "He3" || particleName == "GenericIon") { pmanager->AddProcess(new G4hMultipleScattering, -1, 1, 1); G4ionIonisation* ionIoni = new G4ionIonisation(); ionIoni->SetStepFunction(0.1, 20*um); pmanager->AddProcess(ionIoni, -1, 2, 2);
8/17/09
1.)Convert table to a graph of "Thickness (mils)" on x-axis and "Deflection (
m)" on y-axis. With horizontal line at 20 microns. Any thickness with deflection less than 20 microns may be used.change units to micron and make y-axis logarithmic
- Thermal Expansion Coefficient
In addition to the probability of the mask deflection by its weight, thermal expansion is another effect that may decrease the efficiency of the mask in covering the holes. The thermal expansion coefficient for stainless steel is studied and equals to (um/[7])
): (according toStainless steel type | um/ | (10-6 in/inF) |
Steel Stainless Austenitic (304) | 17.3 | 9.6 |
Steel Stainless Austenitic (310) | 14.4 | 8.0 |
Steel Stainless Austenitic (316) | 16.0 | 8.9 |
Steel Stainless Ferritic (410) | 9.9 | 5.5 |
Copper | 16.6 | 9.3 |
In our case, the plate expansion toward the width is negligible at 260
(assuming the room temperature 20 ), but heating stainless steel (304) plate to the same temperature will cause (0.58mm) change in length! we should be careful as we are welding the ends, or it is better if there is a way to clip the edges to avoid the deflection by length expansion.- Areal thermal expansion
At room temperature, a 0.4 mm length square of stainless steel is going to cover a hole in a copper plate of diameter 0.4 mm. But, as soon as both plates expose to (300
) furnace, the area will increase by the following formula:
So the change in area for SS-plate is 7.6 *10^-4 mm^2, but for the copper is 2.3 * 10^-3 mm^2, a wider mask line should be used.i.e 0.4mm SS-plate width will not cover completely the hole at 300
.
2.) What is uncertainty in the current used to calculate the expected voltage drop.
the uncertainty in voltage can be given by the following formula:
Insert expression for and calculate it using the measured resistances below also propagate error of measured resistances
measured (Mohm) | Voltage (V)measured | I measured (mA) | |
0.56 | 0.01165.0 | 0.1375 | 6.7|
0.47 | 0.0198.6 | 0.1253 | 6.7|
0.42 | 0.0181.5 | 0.1259 | 6.7
Why aren't the currents the same? Measure the voltage and resistance at each junction , compute current and compare
8/19/2009
measured (Mohm) ( | 0.01)Voltage (V)measured ( | 0.1)I (uA) | |
0.56 | 165.0 | 294 | 5|
1.01 | 244.0 | 241 | 2|
0.51 | 99.0 | 194 | 4|
5.51 | 99.0 | 16 | 0.03|
1.02 | 198.6 | 195 | 2|
0.51 | 81.4 | 159 | 0.2|
2.32 | 81.4 | 33 | 0.15|
1.04 | 211.9 | 203 | 2
8/28/2009
1.)Final version of deflection plot
change units to micron and make y-axis logarithmic
2.) Construct table of measured
V for each GEM foil preamp and the predicted V when is 1000, 500, and 200 volts (also try 2 and 4 kV). Use the current measure by CAEN power supply as input to calculation. Measure the voltage difference using a voltmeter.Perhaps our previous inconsistencies were due to bad current measurements?
3.) Dr. Forest installed GEANT 4.9.2 on Inca. But still no ion tracking.
9/8/2009
1.)Final version of deflection plot
Insert caption and increase font size of labels. Try bold lines. Make 20 micron horizontal line dashed. Make theory curve line black and thicker.
Insert paragraph describing the results in the curve
2.) Construct table of measured V for each GEM foil preamp and the predicted V when is 1000, 500, and 200 volts (also try 2 and 4 kV). Use the current measure by CAEN power supply as input to calculation. Measure the voltage difference using a voltmeter.
Perhaps our previous inconsistencies were due to bad current measurements?
Measured | 200V | 500V | 1000V | 2000V | 4000V | |||||
(V) 0.1 | 24.3 | 24 | 359.8 | 61 | 6118.6 | 123 | 12238.0 | 251.4 | 23481.0 | 530.9 | 48
(V) 0.1 | 20.3 | 20 | 350.2 | 51 | 699.9 | 103 | 11201.9 | 211 | 23421.0 | 445 | 48
(V) 0.1 | 18.4 | 18 | 345.3 | 46 | 690.0 | 92.8 | 182.0 | 188 | 22381.0 | 398.2 | 48
(uA) 1 | 43 | 44 | 110 | 111 | 221 | 211 | 449 | 443 | 948 | 885 | 60*
- considering resistance error accumulates for 6 resistances connected in series (each one has 5%).
The measurements show that we have better accuracy in measuring the current and the voltage within the expected range of error.
Now do a table of Vin , and
V Gem 1 ,2,3
3.) Dr. Forest installed GEANT 4.9.2 on Inca. But still no ion tracking.
Koi, Tatsumi Phone: (650) 926-4816 E-Mail: tkoi@SLAC.Stanford.EDU
suggests adding the physics list below
source/physics_lists/lists/src/HadronPhysicsQGSP_BIC.cc
9/10/09 Ion Tracking
You can track CF-232 if you add the line
G4GenericIon::GenericIonDefinition();
to the PhysicsList baryon contructor function as shown below
void ExN02PhysicsList::ConstructBaryons() { // barions G4Proton::ProtonDefinition(); G4AntiProton::AntiProtonDefinition(); G4GenericIon::GenericIonDefinition(); G4Neutron::NeutronDefinition(); G4AntiNeutron::AntiNeutronDefinition(); }
9/15/09
1.)Final version of deflection plot
Insert caption and increase font size of labels. Try bold lines. Make 20 micron horizontal line dashed. Make theory curve line black and thicker.
Insert paragraph describing the results in the curve.
The curve represents the relationship between the thickness and the deflection for a plate of stainless steel of width 0.4 mm and length 140mm when the weight is the only force that acts on it. Please look at [8] for more details about the factors that affects the value of the deflection. The dashed line in the graph intersects with the with deflection line to determine the needed thickness for the plate to have a deflection of 20 um.
Now do a table of Vin , an, and
V Gem 1 ,2,3Measured | 200V | 500V | 1000V | 2000V | 4000V | ? |
(V) 0.1 | 11.9 | 29.8 | 59.1 | 119.2 | 241.7 | 3000 |
(V) 0.1 | 10.2 | 25.2 | 50.8 | 103.2 | 215.5 | 2800 |
(V) 0.1 | 9.21 | 23.1 | 46.1 | 93.2 | 195.5 | 2500 |
[9]. For instance, is the voltage between LP3 and LP4.
is the potential difference between the protection resistance (10 Mohm) and the resistance which is mainly responsible for providing the voltage for the THGEM foil. Please look at the figure9/22/09
1.) deflections
According to the figure I contacted a prof. in civilian engineering, He recommended another formula looks simpler and appropriate for a beam fixed from both sides. I am working on the figure and the information that we may extract from formula.
Enter formula with reference
I also talked to him about anything we should consider affects the mask job when it is heated to 300 degrees Celsius, He suggested to buy a Stainless steel wire (beam) that has the same dimension to the one that will cover a row of holes, then heat it and check what is going to happen to the beam. In other words, build a one beam mask and study what will happen to it (we are considering only weight deflection!)
2.) TGEM HV
Applied Potential (V) | (V) | (V) | (V) | (V) | (V) | (V) |
200 | 24.3 | 11.9 | 20.3 | 10.2 | 18.4 | 9.2 |
500 | 59.8 | 29.8 | 50.2 | 25.2 | 45.3 | 23.1 |
1000 | 118.6 | 59.1 | 103.0 | 50.8 | 90.0 | 46.1 |
2000 | 238.0 | 119.2 | 211.0 | 103.2 | 182.0 | 93.2 |
4000 | 481.0 | 241.7 | 421.0 | 215.5 | 381.0 | 195.5 |
According to the measurements taken, we conclude :
= (approximately) 2
So if
is needed to be as the the table below then the value for can be determined depending on the previous conclusion:
THGEM foil resistance (Mohm) | (V) | (V) | I (mA) | P (W) |
= 0.56 | 3000 | 6000 | 11 | 64 |
= 0.46 | 2800 | 5600 | 12 | 66 |
= 0.42 | 2500 | 5000 | 12 | 61 |
From the table, the power supply potential should be 16,600 V.
Study the 12 Volt power system in the links below and determine how to copy
3.) Resistive paste
I called the paste company [10], there were in process to make the paste in their labs (because of that it took them that long), looks they succeeded, but until now there is not any information about the shipping which will probably be available on Friday. So I will call (bug) them again on that day.
The paste was shipped on Friday, we are expecting to have it by Wednesday Sept. 30, the company should call me again for tracking number! but I will call them tomorrow.
9/29/09
- Paste
The paste was shipped on Friday, we are expecting to have it by Wednesday Sept. 30, the company should call me again for tracking number! but I looks I should call again!
- Deflection vs Thickness
Depending on the equation [11] :
HV
M. Cortesi used a CAEN N471A to individually supply each THGEM stage. The HV supply was set to trip at 50 nA and a 15-20 M Ohm resister was attached in series with the Power supply to limit discharge currents.
Circuit:
The paper gives an idea to how to use the active divider to avoid using more that high voltage power supply, the active divider circuit.
There is a little problem in using that circuit: the maximum voltage provided to the THGEM foil is maximum 1800 V, and that will create a current 22 mA.
Most of the experiments, they starts to run separate HV-power supply connected to a series of high resistances (15- 20 Mohm).
10/6/09
1.) Resistive Paste:
Describe past mixture procedure and curing.
technical data sheetFile:ED7100 Series paste.pdf
safety data sheet File:ED7100 OSHA MSDS.pdf
2.) Change units on deflection plot and insert new plot
3.) Insert link for resistor to use in HV network
references (HV circuit)
4.) Simulation
a.) Zoom in to see target and fission fragments
b.) implement Fission Model G4BertiniEvaporation in Physics list
10/7/09
(n,f) event
I added the following to the physics list
The header files are put into ExN02PhysicsList.cc #include "G4HENeutronInelastic.hh" #include "G4NeutronInelasticProcess.hh" #include "G4CascadeInterface.hh" #include "G4BertiniEvaporation.hh" else if (particleName == "neutron") { G4CascadeInterface* bertiniModel = new G4CascadeInterface(); G4NeutronInelasticProcess* inelProcess = new G4NeutronInelasticProcess(); inelProcess->RegisterMe(bertiniModel); pmanager->AddDiscreteProcess(inelProcess); }
And I saw the event
********************************************************************************************************* * G4Track Information: Particle = neutron, Track ID = 1, Parent ID = 0 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -10 cm 6.5 MeV 0 eV 0 fm 0 fm Target initStep 1 0 fm 0 fm -10 cm 0 eV 0 eV 14.3 nm 14.3 nm Target NeutronInelastic ********************************************************************************************************* * G4Track Information: Particle = U238[0.0], Track ID = 8, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -10 cm 25.7 keV 0 eV 0 fm 0 fm Target initStep 1 -2.14e+03 fm -7.54e+03 fm -10 cm 0 eV 25.7 keV 101 nm 101 nm Target hIoni
By oct. 8 the follwing event is tracked by the GEANT4 with U-238 target with 7 MeV neutron beam:
:********************************************************************************************************* * G4Track Information: Particle = neutron, Track ID = 1, Parent ID = 0 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -10 cm 7 MeV 0 eV 0 fm 0 fm Target initStep 1 0 fm 0 fm -10 cm 7 MeV 0 eV 5 um 5 um Target Transportation 2 0 fm 0 fm -9.85 cm 0 eV 0 eV 1.51 mm 1.51 mm Tracker NeutronInelastic ********************************************************************************************************* * G4Track Information: Particle = N14[0.0], Track ID = 5, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -9.85 cm 1.45 MeV 0 eV 0 fm 0 fm Tracker initStep 1 -63.2 um 33.9 um -9.69 cm 177 keV 1.27 MeV 1.56 mm 1.56 mm Tracker hIoni 2 -181 um 63 um -9.59 cm 0 eV 177 keV 1.13 mm 2.69 mm Tracker hIoni ********************************************************************************************************* * G4Track Information: Particle = gamma, Track ID = 4, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -9.85 cm 382 keV 0 eV 0 fm 0 fm Tracker initStep 1 -2.37 mm -1.45 mm -10 cm 382 keV 0 eV 3.16 mm 3.16 mm Tracker Transportation 2 -2.38 mm -1.45 mm -10 cm 382 keV 0 eV 10.5 um 3.17 mm OutOfWorld Transportation ********************************************************************************************************* * G4Track Information: Particle = gamma, Track ID = 3, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -9.85 cm 1.66 MeV 0 eV 0 fm 0 fm Tracker initStep 1 10 cm 1.17 cm -2.11 cm 1.66 MeV 0 eV 12.7 cm 12.7 cm Tracker Transportation 2 10 cm 1.17 cm -2.11 cm 1.66 MeV 0 eV 6.35 um 12.7 cm OutOfWorld Transportation
I thick we still need to improve the stepping verbose, since whenever the beam is run, there is a limited number of events are detected and usually are the neutrons that just pass, I run the beam only with 100 neutrons only to track the useful ones.
By oct. 12 , fission event is detected after I turned off the inelastic process code using U-238 as target , the result :
### Run 2 start. ********************************************************************************************************* * G4Track Information: Particle = neutron, Track ID = 1, Parent ID = 0 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -10 cm 6.5 MeV 0 eV 0 fm 0 fm Target initStep 1 0 fm 0 fm -10 cm 0 eV 0 eV 131 nm 131 nm Target nFission ********************************************************************************************************* * G4Track Information: Particle = U238[0.0], Track ID = 8, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -10 cm 25.7 keV 0 eV 0 fm 0 fm Target initStep 1 -2.14e+03 fm -7.54e+03 fm -10 cm 0 eV 25.7 keV 101 nm 101 nm Target hIoni ********************************************************************************************************* * G4Track Information: Particle = gamma, Track ID = 7, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -10 cm 96.7 keV 0 eV 0 fm 0 fm Target initStep 1 -759 nm -940 nm -10 cm 96.7 keV 0 eV 3.58 um 3.58 um Target Transportation 2 -4.5 cm -5.58 cm 10 cm 96.7 keV 0 eV 21.2 cm 21.2 cm Tracker Transportation 3 -4.5 cm -5.58 cm 10 cm 96.7 keV 0 eV 3.72 um 21.2 cm OutOfWorld Transportation ********************************************************************************************************* * G4Track Information: Particle = neutron, Track ID = 6, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -10 cm 343 keV 0 eV 0 fm 0 fm Target initStep 1 1.49 um 3.5 um -10 cm 343 keV 0 eV 4.07 um 4.07 um Target Transportation 2 3.46 um 8.14 um -10 cm 343 keV 0 eV 5.4 um 9.47 um World Transportation 3 4.25 cm 10 cm -5.86 cm 343 keV 0 eV 11.6 cm 11.6 cm Tracker Transportation 4 4.25 cm 10 cm -5.86 cm 343 keV 0 eV 4.07 um 11.6 cm OutOfWorld Transportation ********************************************************************************************************* * G4Track Information: Particle = gamma, Track ID = 5, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -10 cm 597 keV 0 eV 0 fm 0 fm Target initStep 1 -2.93 um -3.5 um -10 cm 597 keV 0 eV 4.65 um 4.65 um Target Transportation 2 -11.6 um -13.8 um -10 cm 597 keV 0 eV 13.7 um 18.4 um World Transportation 3 -8.38 cm -10 cm -7.56 cm 597 keV 0 eV 13.3 cm 13.3 cm Tracker Transportation 4 -8.38 cm -10 cm -7.56 cm 597 keV 0 eV 4.65 um 13.3 cm OutOfWorld Transportation ********************************************************************************************************* * G4Track Information: Particle = gamma, Track ID = 4, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -10 cm 1.07 MeV 0 eV 0 fm 0 fm Target initStep 1 210 nm -1.63 um -10 cm 1.07 MeV 0 eV 3.99 um 3.99 um OutOfWorld Transportation ********************************************************************************************************* * G4Track Information: Particle = gamma, Track ID = 3, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -10 cm 1.68 MeV 0 eV 0 fm 0 fm Target initStep 1 -3.06 um 3.5 um -10 cm 1.68 MeV 0 eV 5.24 um 5.24 um OutOfWorld Transportation ********************************************************************************************************* * G4Track Information: Particle = gamma, Track ID = 2, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -10 cm 2.67 MeV 0 eV 0 fm 0 fm Target initStep 1 -1.44 um 3.5 um -10 cm 2.67 MeV 0 eV 3.84 um 3.84 um OutOfWorld Transportation
Fission event is also detected after I turned off the inelastic process code using Th-232 as target , the result :
********************************************************************************************************* * G4Track Information: Particle = neutron, Track ID = 1, Parent ID = 0 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -10 cm 6.5 MeV 0 eV 0 fm 0 fm Target initStep 1 0 fm 0 fm -10 cm 0 eV 0 eV 400 nm 400 nm Target nFission ********************************************************************************************************* * G4Track Information: Particle = Th232[0.0], Track ID = 8, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -10 cm 39 keV 0 eV 0 fm 0 fm Target initStep 1 -2.21e+04 fm -2.88e+04 fm -10 cm 0 eV 39 keV 177 nm 177 nm Target hIoni ********************************************************************************************************* * G4Track Information: Particle = gamma, Track ID = 7, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -10 cm 143 keV 0 eV 0 fm 0 fm Target initStep 1 3.5 um -92.2 nm -10 cm 143 keV 0 eV 4.75 um 4.75 um OutOfWorld Transportation ********************************************************************************************************* * G4Track Information: Particle = gamma, Track ID = 6, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -10 cm 843 keV 0 eV 0 fm 0 fm Target initStep 1 -1.1 um 165 nm -10 cm 843 keV 0 eV 3.29 um 3.29 um Target Transportation 2 -7.09 cm 1.07 cm 10 cm 843 keV 0 eV 21.2 cm 21.2 cm Tracker Transportation 3 -7.09 cm 1.07 cm 10 cm 843 keV 0 eV 3.72 um 21.2 cm OutOfWorld Transportation ********************************************************************************************************* * G4Track Information: Particle = gamma, Track ID = 5, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -10 cm 956 keV 0 eV 0 fm 0 fm Target initStep 1 -1.85 um -2.71 um -10 cm 956 keV 0 eV 5.1 um 5.1 um OutOfWorld Transportation ********************************************************************************************************* * G4Track Information: Particle = gamma, Track ID = 4, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -10 cm 1.42 MeV 0 eV 0 fm 0 fm Target initStep 1 -3.5 um -300 nm -10 cm 1.42 MeV 0 eV 4.41 um 4.41 um OutOfWorld Transportation ********************************************************************************************************* * G4Track Information: Particle = neutron, Track ID = 3, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -10 cm 1.43 MeV 0 eV 0 fm 0 fm Target initStep 1 2.67 um 3.5 um -10 cm 1.43 MeV 0 eV 4.46 um 4.46 um OutOfWorld Transportation ********************************************************************************************************* * G4Track Information: Particle = gamma, Track ID = 2, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -10 cm 1.66 MeV 0 eV 0 fm 0 fm Target initStep 1 393 nm -3.5 um -10 cm 1.66 MeV 0 eV 3.54 um 3.54 um Target Transportation 2 494 nm -4.39 um -10 cm 1.66 MeV 0 eV 904 nm 4.44 um OutOfWorld Transportation >>> Event 0 8 trajectories stored in this event.
10/20/09
1.) Redo resistor network below to reflect one in paper. Find resistance required to have 2000 Volt difference between two the top and bottom of a GEM card and have correct power rating.
Thick_GEM_versus_thin_GEM_in_two_phase_argon_avalanche_detectors (HV circuit)[12]
The new HV-circuit is represented by the figure:
Resistor | value | 0.3[13] | 0.62 [14] | 1 [15] | 1.25 [16] | 1.5 [17] | 2 [18] | 3[19] | 5 [20] | 10[21] | price |
8.6 | 1 | 1 | 1 | 1 | 10.13 | ||||||
4.3 | 1 | 2 | 11.96 | ||||||||
10 | 1 | 5.59 | |||||||||
3.3 | 1 | 1 | 1 | 6.3 | |||||||
4.8 | 1 | 3.95 | |||||||||
total | 2 | 1 | 2 | 4 | 2 | 1 |
according to the suggestion to add new line of resistances as represented in the last figure, this change the the old circuit properties. the following table summarizes these differences:
2_lines _THGEM_circuit | 3l_line_THGEM_circuit | |
Total Resistance (Mohm) | 48.45 | 41.7 |
Current (mA) | 0.31 | 0.36 |
Max. Voltage Per THGEM Foil (V) | (1.43Mohm)444.3 | (1.23Mohm)442.3 |
Power (W) | 0.14 | 0.16 |
2.) reproduce Figure 3 in paper below
http://www.helsinki.fi/~miheikki/system/refs/heikkinen/chep09geant4.pdf
10/27/09 (Paste processing procedure)
- Paste
- HV Circuit
Update the figure for the high voltage circuit.[22]
- Deflection
Figure is updated for the deflection figure.[23]
- Simulation
Chips interface is used but unfortunately the result still the same, a neutron hits then two of them leave without any fragment tracking.
G4StringChipsInterface* theCascade = new G4StringChipsInterface(); G4HadronFissionProcess* fissionProcess = new G4HadronFissionProcess(); fissionProcess->RegisterMe(theCascade); pmanager->AddDiscreteProcess(fissionProcess);
********************************************************************************************************* * G4Track Information: Particle = neutron, Track ID = 1, Parent ID = 0 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -10 cm 6.5 MeV 0 eV 0 fm 0 fm Target initStep 1 0 fm 0 fm -10 cm 0 eV 0 eV 4.31 um 4.31 um Target nFission ********************************************************************************************************* * G4Track Information: Particle = U237[0.0], Track ID = 4, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -10 cm 25.2 keV 0 eV 0 fm 0 fm Target initStep 1 -2.35e+03 fm 4.81e+03 fm -10 cm 0 eV 25.2 keV 99.7 nm 99.7 nm Target hIoni ********************************************************************************************************* * G4Track Information: Particle = neutron, Track ID = 3, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -10 cm 165 keV 0 eV 0 fm 0 fm Target initStep 1 1.44 um -77 nm -10 cm 165 keV 0 eV 1.6 um 1.6 um Target Transportation 2 10 cm -5.35 mm -5.22 cm 165 keV 0 eV 11.1 cm 11.1 cm Tracker Transportation 3 10 cm -5.35 mm -5.22 cm 165 keV 0 eV 5.55 um 11.1 cm OutOfWorld Transportation ********************************************************************************************************* * G4Track Information: Particle = neutron, Track ID = 2, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -10 cm 156 keV 0 eV 0 fm 0 fm Target initStep 1 -2.7 um -5 um -10 cm 156 keV 0 eV 5.69 um 5.69 um Target Transportation 2 -41.9 um -77.6 um -10 cm 156 keV 0 eV 82.6 um 88.3 um OutOfWorld Transportation
10/30/09
- Resistors for THGEM HV-circuit
5 MOHM [24] and [25] | 10 MOHM [26] | |
quantity | 6 | 12 |
11/3/09
- Paste
need to finish procedure in link below. Insert info from vendor describing reducing the paster for an ink jet printer.
Give a copy of paste MSDS to Roy dunker and ask for permission to use their oven located in the LDS hood
- HV Circuit
Update the figure for the high voltage circuit.[27]
Arrange with Tamuna some time to use the power supply to check power on the circuit design.
- Deflection
Redo deflection figure. [28]
- Simulation
reproduce Figure 3 in paper below
11/11/09
- Paste
please follow the link for the update: [29]
- HV Circuit
The circuit were tested as was suggested the figure [30] , very low current was passing through the circuit which relatively decreased the dissipated power through the resistors.
Resistor arrangements and values | Current(P.S.) (uA) | 1Current through each line (uA) | 1 (2 lines only)(V) 1 | (V) 1 | dissipated power (W) | 0.1%
Third circuit [31] | 50 | 25 | 105 | 85 | 0.025 |
removing | 50 | 25 | 136 | 136 | 0.006 |
= 20 Mohm | 41 | 20.5 | 177 | 181 | 0.008 |
= 30 Mohm (with one protection resistor) | 38 | 19 | 195 | 186 | 0.11 |
= 30 Mohm (with all figure resistors) | 38 | 19 | 159 | 122 | 0.11 |
please note that all the previous measurements with
= 1 kV
Result: highly recommended to increase the main resistor(s) which will provide the THGEM foil with needed potential to 30 Mohm which make the current less that 19 uA in each one, but at the same time this will provide each foil with around 200 V when the the power supply is providing 1 kV.So using 15 kV power supply will easily provide each foil with 3000 V (which is our goal).
- Simulation
geant4.9.2.p01/examples/extended/radioactivedecay/exrdm/src
Abla model has a little problem to be defined, I tried to use the following statement in ExN02PhysicsList but unfortunately is not working.
G4InclCascadeInterface* bertiniModel = new G4InclCascadeInterface(); G4AblaFission* fissionProcess = new G4AblaFission(); fissionProcess->RegisterMe(bertiniModel); pmanager->AddDiscreteProcess(fissionProcess);
Depending on a reference used in the same paper File:Abla incl models.pdf, Binary and Bertini models are used for neutron or proton interactions
G4BinaryCascade* bcModel = new G4BinaryCascade(); G4HadronFissionProcess* fissionProcess = new G4HadronFissionProcess(); fissionProcess->RegisterMe(bcModel); pmanager->AddDiscreteProcess(fissionProcess);
(same as ABLA and the results can be compared). So i added Binary Cascade model to ExN02PhysicsList But unfortunately the result is weird!!!
the following error message is not convenient !!
Computed tolerance = 2.0001e-09 mm Target is 0.001 cm of Carbon There are 1 chambers in the tracker region. The chambers are 50 mm of ArgonGas The distance between chamber is 10 cm Segmentation fault
12/8/09
else if (particleName == "proton") { //protons G4InclAblaCascadeInterface *theModel = new G4InclAblaCascadeInterface(); theModel->SetMinEnergy(0.0 * GeV); theModel->SetMaxEnergy(3.0 * GeV); G4ProtonInelasticProcess *protonInelasticProcess = new G4ProtonInelasticProcess(); protonInelasticProcess->AddDataSet(new G4ProtonInelasticCrossSection()); protonInelasticProcess->RegisterMe(theModel); pmanager->AddDiscreteProcess(protonInelasticProcess); } else if (particleName == "neutron") { //neutrons G4InclAblaCascadeInterface *theModel = new G4InclAblaCascadeInterface(); theModel->SetMinEnergy(0.0 * GeV); theModel->SetMaxEnergy(3.0 * GeV); G4NeutronInelasticProcess *neutronInelasticProcess = new G4NeutronInelasticProcess(); neutronInelasticProcess->AddDataSet(new G4NeutronHPFissionData()); neutronInelasticProcess->RegisterMe(theModel); pmanager->AddDiscreteProcess(neutronInelasticProcess);
Below is a sample event which appears to be the reaction
********************************************************************************************************* * G4Track Information: Particle = neutron, Track ID = 1, Parent ID = 0 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -80 cm 10 MeV 0 eV 0 fm 0 fm World initStep 1 0 fm 0 fm -5 mm 10 MeV 0 eV 79.5 cm 79.5 cm World Transportation 2 0 fm 0 fm -1.94 mm 0 eV 0 eV 3.06 mm 79.8 cm Target NeutronInelastic ********************************************************************************************************* * G4Track Information: Particle = In124[16830.9], Track ID = 9, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -1.94 mm 84.1 MeV 0 eV 0 fm 0 fm Target initStep 1 -686 um 1.79 mm -5 mm 84.1 MeV 0 eV 3.61 mm 3.61 mm Target Transportation 2 -17.9 cm 46.7 cm -80 cm 84.1 MeV 0 eV 93.8 cm 94.2 cm OutOfWorld Transportation ********************************************************************************************************* * G4Track Information: Particle = neutron, Track ID = 8, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -1.94 mm 215 keV 0 eV 0 fm 0 fm Target initStep 1 -3.93 mm -5 mm -3.86 mm 215 keV 0 eV 6.64 mm 6.64 mm Target Transportation 2 -62.9 cm -80 cm -30.8 cm 215 keV 0 eV 1.06 m 1.06 m OutOfWorld Transportation ********************************************************************************************************* ********************************************************************************************************* * G4Track Information: Particle = neutron, Track ID = 7, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -1.94 mm 2.42 MeV 0 eV 0 fm 0 fm Target initStep 1 -2.86 mm 271 um -5 mm 2.42 MeV 0 eV 4.2 mm 4.2 mm Target Transportation 2 -74.8 cm 7.07 cm -80 cm 2.42 MeV 0 eV 1.09 m 1.1 m OutOfWorld Transportation ********************************************************************************************************* * G4Track Information: Particle = Tc109[16830.9], Track ID = 6, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -1.94 mm 90.1 MeV 0 eV 0 fm 0 fm Target initStep 1 -2.79 mm 1.98 mm -5 mm 90.1 MeV 0 eV 4.59 mm 4.59 mm Target Transportation 2 -73 cm 51.8 cm -80 cm 90.1 MeV 0 eV 1.19 m 1.2 m OutOfWorld Transportation ********************************************************************************************************* * G4Track Information: Particle = neutron, Track ID = 5, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -1.94 mm 2.85 MeV 0 eV 0 fm 0 fm Target initStep 1 -2.26 mm 5 mm -3.15 mm 2.85 MeV 0 eV 5.62 mm 5.62 mm Target Transportation 2 -36.2 cm 80 cm -19.5 cm 2.85 MeV 0 eV 89.4 cm 89.9 cm OutOfWorld Transportation ********************************************************************************************************* * G4Track Information: Particle = neutron, Track ID = 4, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -1.94 mm 1.36 MeV 0 eV 0 fm 0 fm Target initStep 1 -4.91 mm 5 mm -4.1 mm 1.36 MeV 0 eV 7.33 mm 7.33 mm Target Transportation 2 -78.6 cm 80 cm -34.6 cm 1.36 MeV 0 eV 1.17 m 1.17 m OutOfWorld Transportation ********************************************************************************************************* * G4Track Information: Particle = neutron, Track ID = 3, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -1.94 mm 7.03 MeV 0 eV 0 fm 0 fm Target initStep 1 -2.6 mm 5 mm -2.38 mm 7.03 MeV 0 eV 5.65 mm 5.65 mm Target Transportation 2 -41.6 cm 80 cm -7.21 cm 7.03 MeV 0 eV 89.9 cm 90.4 cm OutOfWorld Transportation ********************************************************************************************************* * G4Track Information: Particle = neutron, Track ID = 2, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -1.94 mm 287 keV 0 eV 0 fm 0 fm Target initStep 1 1.54 mm -3.74 mm -5 mm 287 keV 0 eV 5.07 mm 5.07 mm Target Transportation 2 33 cm -80 cm -65.6 cm 287 keV 0 eV 1.08 m 1.08 m OutOfWorld Transportation >>> Event 4 9 trajectories stored in this event. 5 events have been kept for refreshing and/or reviewing.
12/14/09
1.) For class project overlap GEANT4 fission atomic mass distribution with data locate in NIM article: n U-235 measurements : Diiorio NIM vol B147 (1977)487
2.) Create Xmgrace file to reproduce graph below. Upload original measurements and make a table in the wiki.
File:Tingjin IntConfNucDataforScienceTech 2007.pdf
3.) HV measurements
- Pb Proton-fission
The mass number is tracked for the fragment instead of he name by
1-Edit ExN02SteppingVerbose.cc in for-loop, replace ParticleName by AtomicMass.
2- Add the the following to for-loopif:
(fTrack->GetDefinition()->GetPDGEncoding()==2212 &&fStep->GetPostStepPoint()->GetProcessDefinedStep()->GetProcessName()=="NeutronInelastic" && fTrack->GetVolume()->GetName() =="Target" && (*fSeco$) [lp1]->GetDefinition()->GetAtomicMass()>1) outfile << (*fSecondary)[lp1]->GetDefinition()->GetAtomicMass()
n U-235 measurements : Diiorio NIM vol B147 (1977)487
File:Tingjin IntConfNucDataforScienceTech 2007.pdf
Th-232 Fission CrossSection
12/15/2009
- Thermal Neutron and U_235 fission
- File:Diiorio NIM vol B147 (1977)487.pdf
1) For thermal neutron (0.025 MeV) we can not use the same class mentioned in [32] th Simulation were running for a long time but not event.
2) Different Neutron data sets were used also:
neutronInelasticProcess->AddDataSet(new G4HadronFissionDataSet()); (does not give any event) neutronInelasticProcess->AddDataSet(new G4NeutronHPorLFissionData());(compiles perfectly but GEANT4 crashes after 1st neutron fired)
3) Recently a new presentation done by describes the the thermal neutron interactions, he is replacing the Inelastic process to Elastic process even registered by other classes or used with neutron data sets. File:THermal neutrons interactions.pdf
01/05/10
- Simulation of the mass distribution spectra for Throrium-232 for 7.5 MeV
(1st figure is the full spectrum but the 2nd one for a>1)
Three kinds of events tracked :
********************************************************************************************************* * G4Track Information: Particle = neutron, Track ID = 1, Parent ID = 0 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -80 cm 7.5 MeV 0 eV 0 fm 0 fm World initStep 1 0 fm 0 fm -5 mm 7.5 MeV 0 eV 79.5 cm 79.5 cm World Transportation 2 0 fm 0 fm -3.06 mm 0 eV 0 eV 1.94 mm 79.7 cm Target NeutronInelastic :----- List of 2ndaries - #SpawnInStep= 3(Rest= 0,Along= 0,Post= 3), #SpawnTotal= 3 --------------- : 0 fm 0 fm -3.06 mm 578 keV 1 : 0 fm 0 fm -3.06 mm 291 keV 1 : 0 fm 0 fm -3.06 mm 35.5 keV 231 :----------------------------------------------------------------- EndOf2ndaries Info --------------- ********************************************************************************************************* * G4Track Information: Particle = Th231[14330.9], Track ID = 4, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -3.06 mm 35.5 keV 0 eV 0 fm 0 fm Target initStep 1 251 um 2.7 mm 5 mm 35.5 keV 0 eV 8.5 mm 8.5 mm Target Transportation 2 2.43 mm 2.61 cm 7.5 cm 35.5 keV 0 eV 7.39 cm 8.24 cm World Transportation 3 3.17 mm 3.41 cm 9.87 cm 35.5 keV 0 eV 2.5 cm 10.7 cm Tracker StepLimiter 4 3.91 mm 4.2 cm 12.2 cm 35.5 keV 0 eV 2.5 cm 13.2 cm Tracker StepLimiter 5 4.65 mm 4.99 cm 14.6 cm 35.5 keV 0 eV 2.5 cm 15.7 cm Tracker StepLimiter 6 5.39 mm 5.79 cm 17 cm 35.5 keV 0 eV 2.5 cm 18.2 cm Tracker StepLimiter 7 6.12 mm 6.58 cm 19.3 cm 35.5 keV 0 eV 2.5 cm 20.7 cm Tracker StepLimiter 8 6.86 mm 7.37 cm 21.7 cm 35.5 keV 0 eV 2.5 cm 23.2 cm Tracker StepLimiter 9 6.98 mm 7.5 cm 22.1 cm 35.5 keV 0 eV 3.94 mm 23.6 cm Tracker Transportation 10 2.5 cm 26.9 cm 80 cm 35.5 keV 0 eV 61.1 cm 84.7 cm OutOfWorld Transportation ********************************************************************************************************* * G4Track Information: Particle = neutron, Track ID = 3, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -3.06 mm 291 keV 0 eV 0 fm 0 fm Target initStep 1 -624 um -1.4 mm -5 mm 291 keV 0 eV 2.47 mm 2.47 mm Target Transportation 2 -25.6 cm -57.4 cm -80 cm 291 keV 0 eV 1.01 m 1.02 m OutOfWorld Transportation ********************************************************************************************************* * G4Track Information: Particle = neutron, Track ID = 2, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -3.06 mm 578 keV 0 eV 0 fm 0 fm Target initStep 1 434 um -5 mm 811 um 578 keV 0 eV 6.34 mm 6.34 mm Target Transportation 2 6.94 cm -80 cm 61.6 cm 578 keV 0 eV 1.01 m 1.01 m OutOfWorld Transportation
- and
********************************************************************************************************* * G4Track Information: Particle = neutron, Track ID = 1, Parent ID = 0 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -80 cm 7.5 MeV 0 eV 0 fm 0 fm World initStep 1 0 fm 0 fm -5 mm 7.5 MeV 0 eV 79.5 cm 79.5 cm World Transportation 2 0 fm 0 fm -2.2 mm 0 eV 0 eV 2.8 mm 79.8 cm Target NeutronInelastic :----- List of 2ndaries - #SpawnInStep= 2(Rest= 0,Along= 0,Post= 2), #SpawnTotal= 2 --------------- : 0 fm 0 fm -2.2 mm 1.91 MeV 1 : 0 fm 0 fm -2.2 mm 19.7 keV 232 :----------------------------------------------------------------- EndOf2ndaries Info --------------- ********************************************************************************************************* * G4Track Information: Particle = Th232[5594.3], Track ID = 3, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -2.2 mm 19.7 keV 0 eV 0 fm 0 fm Target initStep 1 -560 um -4.06 mm 5 mm 19.7 keV 0 eV 8.29 mm 8.29 mm Target Transportation 2 -6 mm -4.35 cm 7.5 cm 19.7 keV 0 eV 8.06 cm 8.88 cm World Transportation 3 -7.69 mm -5.58 cm 9.67 cm 19.7 keV 0 eV 2.5 cm 11.4 cm Tracker StepLimiter 4 -9.37 mm -6.81 cm 11.8 cm 19.7 keV 0 eV 2.5 cm 13.9 cm Tracker StepLimiter 5 -1.03 cm -7.5 cm 13.1 cm 19.7 keV 0 eV 1.42 cm 15.3 cm Tracker Transportation 6 -6.23 cm -45.2 cm 80 cm 19.7 keV 0 eV 77 cm 92.3 cm OutOfWorld Transportation ********************************************************************************************************* * G4Track Information: Particle = neutron, Track ID = 2, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -2.2 mm 1.91 MeV 0 eV 0 fm 0 fm Target initStep 1 689 um 5 mm 2.07 mm 1.91 MeV 0 eV 6.61 mm 6.61 mm Target Transportation 2 11 cm 80 cm 68.1 cm 1.91 MeV 0 eV 1.05 m 1.06 m OutOfWorld Transportation
- In addition to the fission event
********************************************************************************************************* * G4Track Information: Particle = neutron, Track ID = 1, Parent ID = 0 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm -80 cm 7.5 MeV 0 eV 0 fm 0 fm World initStep 1 0 fm 0 fm -5 mm 7.5 MeV 0 eV 79.5 cm 79.5 cm World Transportation 2 0 fm 0 fm 1.2 mm 0 eV 0 eV 6.2 mm 80.1 cm Target NeutronInelastic :----- List of 2ndaries - #SpawnInStep= 7(Rest= 0,Along= 0,Post= 7), #SpawnTotal= 7 --------------- : 0 fm 0 fm 1.2 mm 138 keV 1 : 0 fm 0 fm 1.2 mm 2.37 MeV 1 : 0 fm 0 fm 1.2 mm 78.3 MeV 123 : 0 fm 0 fm 1.2 mm 1.83 MeV 1 : 0 fm 0 fm 1.2 mm 4.17 MeV 1 : 0 fm 0 fm 1.2 mm 653 keV 1 : 0 fm 0 fm 1.2 mm 89.1 MeV 105 :----------------------------------------------------------------- EndOf2ndaries Info --------------- ********************************************************************************************************* * G4Track Information: Particle = Mo105[14330.9], Track ID = 8, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm 1.2 mm 89.1 MeV 0 eV 0 fm 0 fm Target initStep 1 5 mm 442 um 1.9 mm 89.1 MeV 0 eV 5.07 mm 5.07 mm Target Transportation 2 80 cm 7.07 cm 11.4 cm 89.1 MeV 0 eV 80.6 cm 81.1 cm OutOfWorld Transportation ********************************************************************************************************* * G4Track Information: Particle = neutron, Track ID = 7, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm 1.2 mm 653 keV 0 eV 0 fm 0 fm Target initStep 1 5 mm 1.85 mm 719 um 653 keV 0 eV 5.35 mm 5.35 mm Target Transportation 2 80 cm 29.7 cm -7.55 cm 653 keV 0 eV 85.1 cm 85.7 cm OutOfWorld Transportation ********************************************************************************************************* * G4Track Information: Particle = neutron, Track ID = 6, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm 1.2 mm 4.17 MeV 0 eV 0 fm 0 fm Target initStep 1 4.44 mm 1.75 mm -5 mm 4.17 MeV 0 eV 7.82 mm 7.82 mm Target Transportation 2 57.4 cm 22.6 cm -80 cm 4.17 MeV 0 eV 1 m 1.01 m OutOfWorld Transportation ********************************************************************************************************* * G4Track Information: Particle = neutron, Track ID = 5, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm 1.2 mm 1.83 MeV 0 eV 0 fm 0 fm Target initStep 1 2.07 mm 3.07 mm 5 mm 1.83 MeV 0 eV 5.31 mm 5.31 mm Target Transportation 2 4.01 cm 5.96 cm 7.5 cm 1.83 MeV 0 eV 9.77 cm 10.3 cm World Transportation 3 5.05 cm 7.5 cm 9.41 cm 1.83 MeV 0 eV 2.66 cm 13 cm Tracker Transportation 4 43.4 cm 64.5 cm 80 cm 1.83 MeV 0 eV 98.5 cm 1.11 m OutOfWorld Transportation ********************************************************************************************************* * G4Track Information: Particle = Cd123[14330.9], Track ID = 4, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm 1.2 mm 78.3 MeV 0 eV 0 fm 0 fm Target initStep 1 -5 mm -1.83 mm 485 um 78.3 MeV 0 eV 5.37 mm 5.37 mm Target Transportation 2 -80 cm -29.3 cm -11.3 cm 78.3 MeV 0 eV 85.4 cm 86 cm OutOfWorld Transportation ********************************************************************************************************* * G4Track Information: Particle = neutron, Track ID = 3, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm 1.2 mm 2.37 MeV 0 eV 0 fm 0 fm Target initStep 1 -5 mm 328 um 1.75 mm 2.37 MeV 0 eV 5.04 mm 5.04 mm Target Transportation 2 -80 cm 5.25 cm 8.89 cm 2.37 MeV 0 eV 80.1 cm 80.7 cm OutOfWorld Transportation ********************************************************************************************************* * G4Track Information: Particle = neutron, Track ID = 2, Parent ID = 1 ********************************************************************************************************* Step# X Y Z KineE dEStep StepLeng TrakLeng Volume Process 0 0 fm 0 fm 1.2 mm 138 keV 0 eV 0 fm 0 fm Target initStep 1 5 mm 2.66 mm 3.68 mm 138 keV 0 eV 6.18 mm 6.18 mm Target Transportation 2 80 cm 42.6 cm 39.9 cm 138 keV 0 eV 98.3 cm 99 cm OutOfWorld Transportation
- Voltage Measurements when the THGEM resistor is 30 Mohm in [33] fig.3
(kV) 0.001 | (kV) 0.001 | (kV) 0.001 | (kV) 0.001 |
1.058 | 0.410 | 0.403 | 0.394 |
2.057 | 0.798 | 0.780 | 0.763 |
3.020 | 1.169 | 1.145 | 1.120 |
4.021 | 1.557 | 1.524 | 1.492 |
5.066 | 1.961 | 1.920 | 1.879 |
6.080 | 2.353 | 2.302 | 2.253 |
7.041 | 2.721 | 2.662 | 2.607 |
8.094 | 3.122 | 3.058 | 2.989 |
9.065 | 3.495 | 3.420 | 3.346 |
10.120 | 3.896 | 3.814 | 3.733 |
11.135 | 4.281 | 4.192 | 4.097 |
12.032 | 4.619 | 4.520 | 4.422 |
13.017 | 4.992 | 4.883 | 4.760 |
01/11/10
- HV circuit
The table below shows the voltage measurements for the HV circuit represented by fig.3 [34] with THGEM-resistor is 180 Mohm. The input voltage choice is based on the maximum voltage capability of the available power supplies in LDS until the date above.
(kV) 0.001 | (kV) 0.001 | (kV) 0.001 | (kV) 0.001 |
1.030 | 0.087 | 0.800 | 0.790 |
4.005 | 3.158 | 3.100 | 3.066 |
5.010 | 3.949 | 3.887 | 3.836 |
8.009* | 6.300 | 6.214 | 6.136 |
*Expected a higher voltage measurements for THGEM resistors closer to the voltage of source if THGEM resistors are replaced by resistor of 250-300 Mohm.
1/22/10
1.) Paste practice
The paste was applied on a G-10 that has 1 mm hole diameter and 0.5mm and 1mm pitch. After curing the paste made a solid surface on the top on the G-10 surface without penetrating through the holes or dropping on the carrier.
insert picture
insert resistance measurements
insert voltage difference measurements
Next paste practice.
Apply paste to PC board without drilling holes. Try to get copper layer for connections. Don't worry about PC board thickness
Order FR4 boards clad on both sides with copper that are the same thickness as the ones in the paper.
2.) HV distributions
What happens when a 30 mv pulse is pushed onto the ground plane. Do you see it through the capacitor?
3.) GEANT4 simulation:
A fission fragment distribution from Th-232 was observed. Now working on X-section.
A new physics model was installed and is working called "G4HadronFission".
The goal is to compare this model with "G4Inelastic".
Which one reproduces cross section?
Table with data from measurements.
http://www.nndc.bnl.gov/exfor/endf.htm
02/12/10
- ED-7100 picture
insert resistance measurements
insert voltage difference measurements
Next paste practice.
Apply paste to PC board without drilling holes. Try to get copper layer for connections. Don't worry about PC board thickness
- Order FR4
Order FR4 boards clad on both sides with copper that are the same thickness as the ones in the paper. There are the following kinds of laminates that we can use for the TGEM:
Laminate | Dielectric Constant (</math> (kV) | 0.05)The Least Thickness (mm) |
RO4003C | 3.38 | 0.101 |
RO4350B | 3.48 | 0.203 |
RO3035 | 3.5 | 0.13 |
RO3003 | 3.00( | 0.04)0.13 |
RO3006 | 6.15( | 0.15)0.13 |
RO3010 | 10.2( | 0.3)0.13 |
RO4360 | 6.15 ( | 0.15)0.203 |
Theta | 3.9-4.01(without uncertainty) | 0.056 |
It is possible also to have copper on the chosen laminate with 17 um thickness. the laminate thckness last update is available on the following:File:Standard Thicknesses, Tolerances and Panel Sizes.pdf
Based on a call done by 02/11/10:
1- The company can provide us with 30 mil (0.76 mm) and 40 mil (1.02 mm) FR4 thickness plates.
2- The minimum copper thickness is 17um which is equivalent to 1/2 oz.
3-The prices are as the following
FR4-Thickness | Copper thickness(um) | price per 12"X18" plate(305X457mm) (us $) | expected laminate series |
30 mil (0.76 mm) | 17 | 70.17 | 3003 |
40 mil (1.02 mm) | 17 | 99.01 | 3003 |
9 | 99.01 | 5880 |
Please note:
1- Expected change in pricing whenever you call for order but this is just an estimation.
2- The price of the copper double sided is the same as one-sided ones ??
3- the order would be ready within 2 weeks from the date of order.
4- for non-standard thickness, the customer is expected to buy the whole yeild. (usually is 6 plates but not always!)
5- the minimum order is 150$.
6- Copper single sided or double sided is possible depending on the thickness of the chosen laminate.
For ordering : call Melody on (480-961-8249) who is a busy lady as described (do not be upset if you have to leave a voicemail) or call 800-227-6437 for any additional information on their products.
- Important
The order can not be by individuals, the faster way is to make under the university name in a formal paper which determines exactly what we want, Melody is helpful and ready to answer any question such that we will sure 100% of every small detail.
2.) HV distributions
What happens when a 30 mv pulse is pushed onto the ground plane. Do you see it through the capacitor?
- GEANT4 simulation
there are two classes that can simulate the Th-232 fission process,
a- G4InelasticProcess . [[35]] b- G4HardronFission. the following should be added to the ExN02PhysicsList.cc :
A fission fragment distribution from Th-232 was observed. Now working on X-section.
G4InclAblaCascadeInterface *theModel = new G4InclAblaCascadeInterface(); theModel->SetMinEnergy(0.0 * GeV); theModel->SetMaxEnergy(3.0 * GeV); G4HadronFissionProcess *theFissionProcess = new G4HadronFissionProcess(); theFissionProcess->AddDataSet(new G4NeutronHPFissionData()); theFissionProcess->RegisterMe(theModel); pmanager->AddDiscreteProcess(theFissionProcess);
To compare this model with "G4Inelastic", the simulation is run for just a 100 neutrons, ExN02SteppingVerbose.cc can distinguish between a reaction of one fission fragment (dominant) or two fission fragments(used for calculating the fission cross section for Th-232).
The previous figure is based on the following calculation.File:Xsection cal.txt
Which one reproduces cross section?
Table with data from measurements.
http://www.nndc.bnl.gov/exfor/endf.htm the website helps to generate graphs depending on the data-libraries stored. after you choose your element you can plot and add more data to your plot. the previous plot for the Th-232 is generated by the same website.[[36]]
2/16/10
1.) Cross section from Simulation
Th-232 is a cube 10 x 10 x 10 cm^3.
The number of incident particles per Area =
X-sect =
- barns
2.) Output a file with fission fragments events containing energy and momentum for each fragment as well as incident neutron energy
3.) Check on status of Additive T
4.) Order FR4 to make GEm foils
FR4 thickness is 1 mm = 30 mil with a standard copper thickness 17 microns ( half ounce). = model 3003
call Melody on (480-961-8249) who is a busy lady as described (do not be upset if you have to leave a voicemail) or call 800-227-6437 for any additional information on their products.
$200 , 30 mil , 3003 series 1/2 x 1/2 oz
5.) Insert table with power through resisters in HV circuit. This will determine if the resisters can sustain the voltage. Afterword , short the GEM foil connection and determine change in power requirements.
6.)Measure voltage difference for several points across front and back of board coated with resistive paste.
02/22/10
- Th-Fission Simulation
The following table represents the fission products and their physical parameters for Th-fission process that covers the range 22-12 MeV.
Neutron Kinetic Energy (MeV) | Atomic Number | Atomic Mass | Kinetic Energy(MeV) | (N/s) | ||
22 | 47 | 118 | 79.313 | 1047.05 | -2848.8 | -2866.72 |
22 | 43 | 105 | 91.7065 | -80.3602 | 3421.92 | -2493.52 |
20 | 47 | 117 | 80.9944 | -3948.01 | -1374.8 | -413.714 |
20 | 47 | 117 | 80.9944 | -3948.01 | -1374.8 | -413.714 |
17 | 43 | 108 | 85.0977 | 2021.82 | 3575.92 | 491.487 |
17 | 47 | 119 | 78.2587 | 3372.27 | -2402.48 | -446.444 |
15 | 43 | 110 | 83.1197 | 3527.28 | -2094.98 | -442.242 |
15 | 47 | 118 | 81.6169 | -2762.52 | -3144.03 | -645.413 |
12 | 43 | 110 | 83.6868 | 233.754 | -2554.97 | -3249.9 |
12 | 47 | 118 | 80.4392 | -417.031 | 2668.67 | 3221.85 |
Events look good now make a text file with all information about event on one line (neutronEin,Afrag1,Afrag2,Zfrag1,Zfrag2, Efrag1,Efrag2,Pxfrag1,Pxfrag2...)
- HV-circuit Pwer Measurements
Voltage (kV)( | 0.001)Current( | 1 uA)Power (W) |
0.500 | 8 | 0.0013 |
1.000 | 14 | 0.0039 |
1.500 | 21 | 0.0088 |
2.000 | 27 | 0.0146 |
2.500 | 33 | 0.0218 |
3.000 | 40 | 0.0320 |
3.500 | 46 | 0.0423 |
4.000 | 53 | 0.0562 |
4.500 | 60 | 0.0720 |
5.000 | 66 | 0.0871 |
6.000 | 80 | 0.1280 |
7.000 | 91 | 0.1656 |
8.000 | 104 | 0.2163 |
Availability 2.5W : 200 Mohm [37], 300 [38], 400 [39] , 500 [40]
03/05/10
A 1"X1" laminate was shorted to around 1kV after following the preparing procedure below. The difference in voltage between the two surfaces is 869 V over all the paste area (I tried to make it as thin as possible and had the whole free copper free covered with a little contact to the copper frame), the board starts to spark when the voltage raised up to 2 kV.
I would suspect that the short is due to the copper at the outside edge of the laminate. You should smooth the surface using sandpaper. Perhaps we may even need to etch the outer edge copper away from the edge.
Yes, That was the reason, I removed the copper close to the edge, I succeeded to to reach 5k without sparking. I am now in process to repeat the experiment but the copper on the edge will be removed by the etching solution leaving just a little frame for connection.
- 3000series laminate preparing procedure
1- Get a laminate with a desired dimensions etched by copper etchant solution after covering part of it to form a copper frame.
2- Paste the ED-7100 to free free copper area with a little contact with the frame.
3- Cure the paste.
4- Short the laminate with a power source.
03/09/10
- HV circuit
The TGEM-plate was connected to the circuit, the source voltage was 1kV, but still the current is passing through the circuit where
.1.) Insert Fission Fragment plots for different neutron energies.
2.) Run simulations for neutron energies between 1 and 20 MeV, 1 MeV steps.
3) Plot X-sect.
4.) Construct PCB GEM cards and insert into HV network. Measure Current and Voltage to determine power.
5.) Drill 5 holes into one of the GEM cards and determine voltage for sparks.
- Thorioum like material
An email is sent to Dr.Patricia (Patricia.Paviet-Hartmann@unlv.edu) about a Thorium like materially physically and chemically, she suggested to use Cerium oxide(IV). I contacted chemistry material shop they said there is but it is very little, a call is needed to Mark to make an order.
safety datasheet [41]
- RF-Connectors and adapters
The best prices founded on [42] Please look at the top of the blue box, there is a line where you can find what they offer.
03/30/10
- HV Circuit
1.) Using the new resistance 300 Mohm the current still runs throught the circuit.
(no 4.7 M resistor) | |||
1.000 | 10 | 0.220 | 0.220 |
2.000 | 18 | 0.493 | 0.440 |
3.000 | 27 | 0.734 | 0.654 |
4.000 | 36 | 0.983 | 0.874 |
5.000 | 45 | (higher than 1.1kV) | 1.084 |
The difference between the 3rd column and 4th column measurements is one of THGEM1 has a 4.7 Mohm resistor disconnected.
2.) The design for for one of the THGEM circuit lines is created by eagle,the bottom picture shows only the board within only the available space (3cm X 13cm). Unfortunately the space for the ciruit board that is available now is not enough, a new cavity will be engraved on the other side and its size is big as 6cm X 20cm X enough height to havethe resistors inside.
- Paste and the new laminate
the paste is applied on the laminate by etching all the copper on both side leaving a copper frame with 0.2cm width only away from edge 0.5cm. Successes achieved in following :
a) Sharpie perminent is the best for covering the copper to keep it on the desired shape on the laminate.
b) No sparking on the on the laminate surface (without holes) that is etched and covered with the paste unless the voltage is higher that 9 kV.
Still the work is continuing to test the same laminate dimensions covered with the paste but with a certain number of holes on its surface.
- Simulations
A simulations were run for the TH-232 fission fragment using abla interface with hadron fission model and InelasticProcess model.
The two models are giving the same results.
04/09/10
- Sparking Test
A new laminate is cut and covered by resistive paste, a number of holes are created in pattern close to that of THGEM (but the distances are not the same among the holes as those in the pattern). The test led to the following conclusions:
1- The laminate passed 3kV, it started to spark after that value since the design has some defects, a perfect design by the CNC-machines will help to pass this value easily.
2-The distances among the holes is very important, even after applying the resistive paste, the further from each other is the better to avoid sparking.
3- Adding Cerium to the paste has not any effect on the paste resistivity.
4-The new laminate is softer than the the G-10 that was used before, attention to not to bend it specially after the design, the holes will make it easily damaged under a little strong hand pressure on any side, for a better efficiency, the surface needs to be flat.
04/20/10
1.) order HV boards ( a.) print out full scale version and check fit, b.) determine places to mill, c.) check max size of PCboard sheet)
2.) HV test copper GEM PCboards. apply paste to reduce sparking
3.) Run GEANT4 programs on all available computers
4.) Dr. Brey has U-238, can we have it and destroy it?
5.) Solution for making more TGEMs.
a.) Design in CAD and ship to CNC place? b.) apply paste before or after drilling? (Th-232 doped paste is a contamination hazard.) c.) Paste application method (Printer or brushes)
05/4/10
1.) order HV boards
( a.) print out full scale version and check fit,
Done, waiting for Dr. Forest to inspect
b.) determine places to mill,
currently have a milled area for HV which is 10cm x 3 cm. We need to create a 13 x 8 cm area to hold the above design.
c.) check max size of PCboard sheet)
2.) HV test copper GEM PCboards. apply paste to reduce sparking
Machine 4 mini-TGEMs.
3.) Run GEANT4 programs on all available computers
put G4 runs on Brems
4.) Dr. Brey has U-238, can we have it and destroy it?
5.) Solution for making more TGEMs.
a.) Design in CAD and ship to CNC place?
Free CAD drawing exists
b.) apply paste before or after drilling? (Th-232 doped paste is a contamination hazard.)
Paste then drill. Need to take care of radioactive waste.
c.) Paste application method (Printer or brushes)
Order Ink Jet printer which will work with DAQ machine (Unix) then practice.
05/18/10
1.) Finish laying out HV design.
currently have a milled area for HV which is 10cm x 3 cm. We need to create a 13 x 8 cm area to hold the above design.
a.) check max size of PCboard sheet)
maybe 11" x 18" we can get HV board on there no problem. Now optimize number of boards per 11" x 18" PC board.
b.) Insert picture in wiki with paper representing PCboard sizes layed on top of detector.
c.) Get some quotes
2.) Machine 4 mini-TGEMs.
check out moving drill press to mill machine table.
Build collar for drill bit.
3.) Run GEANT4 programs on all available computers
put G4 runs on Brems
http://wiki.iac.isu.edu/index.php/Running_With_Slurm Batch jobs on Brehms
Install Ionization for ion fragments.
Plot current results using inca and DAQ computer with error bars.
4.) Dr. Brey has U-238, can we have it and destroy it?
5.) Solution for making more TGEMs.
Advanced Circuit did the copper TGEMS, will they do another coated with Th-232. I doubt it.
a.) Send CAD drawings to Advanced Cicuits for quotes. A CAD design exists, need to quality control check it, can a vendor read it? Remember copper only around perimeter.
b.) Is there a vendor willing to drill.
Paste then drill. Need to take care of radioactive waste.
Need to develop method to apply doped paste to circuit board with holes.
Look for plastic plugs to go into the holes.
c.) Paste application method (Printer or brushes)
Order Ink Jet printer which will work with DAQ machine (Unix) then practice.
4/06/10 (HV-circuit Design)(Ionization)
1.) Finish laying out HV design.
currently have a milled area for HV which is 10cm x 3 cm. We need to create a 13 x 8 cm area to hold the above design.
a.) check max size of PCboard sheet)
maybe 11" x 18" we can get HV board on there no problem. Now optimize number of boards per 11" x 18" PC board.
b.) Insert picture in wiki with paper representing PCboard sizes layed on top of detector.
c.) Get some quotes
The PC-boards design is done, Gerber files are also created and submitted to the Board house (Circuit Graphics [43]). I am waiting for the price.
2.) Machine 4 mini-TGEMs.
check out moving drill press to mill machine table.
Build collar for drill bit.
I made a visit to milling workshop in the university, they checked for me the milling machine in the beam lab, they advice me to check the utilities to check the electric connections (I asked Sanda to have maintenance request to check the connections), the machine now is ok and everything is working ok except for :
1- Electric lever key that takes the table up and down needs to be replaced.
2- The drill has a strange sound when it runs slow, but it is good as it runs fast.
3- The data reader is not working (important for small displacements).
In the utilities Department there is a technician (Paul (Dee) Rasmussen x2694 ) who used to do all the maintenance for the CNC and milling machines the milling lab, I asked the department to submit a maintenance request to check and try to fix the above in our machine. (an email is sent to you describes what is needed to go further in this).
I borrowed an adapter to catch very small drill bit, it works manually to avoid breaking the bit. Also I visited General products (tools shop) to buy 0.4 mm drill bit and an adapter to catch it . I tried more than once to use this drill bit to get holes on TGEM plate, it is working good but there are still some difficulties in the displacements, I hoping the situation will be much better after fixing the data reader.
Bridgeport Series I Milling Machine
Brian Denny at Asi Machine & Supply - www.asimachine.com (208) 888-9236 will come by and give us a cost repair estimate when he or a fellow worker is in the area.
Brian Bishop is the Asi rep which travels to ISU frequently (one a month). His Cell number is 208-573-1765. The best repair tactic is to remove the head and ship it to Boise. Or if not in a hurry, wait for Brian to come back to town and he will take it back with him.
3.) Run GEANT4 programs on all available computers
put G4 runs on Brems
http://wiki.iac.isu.edu/index.php/Running_With_Slurm Batch jobs on Brehms
Install Ionization for ion fragments.
Find a measurement to compare the ionization of the gas to. A light or heavy ion traveling through as gas chamber liberates ? electrons by ionization.
GEANT4 is running with the ionization, the chamber material now is Ar 90 \percent with 10 \percent CO2.
Both ExN02DetectorConstruction.cc and ExN02PhysicsList.cc were edited as the following:
To add ArCO2 mixture: G4Material* ArCO2=new G4Material("ArCO2",density,ncomponents=2); ArCO2->AddMaterial(Ar,fractionmass=90*perCent); ArCO2->AddMaterial(CO2 ,fractionmass=10*perCent); To track the fission fragments: else if( particleName == "alpha" || particleName == "He3" || particleName == "GenericIon" ) { //Ions //pmanager->AddProcess(new G4hMultipleScattering, -1, 1, 1); pmanager->AddProcess(new G4ionIonisation, -1, 2, 2); }
The text file contains:
En FF1A FF1Z FF1P px py pz FF1Range chargeFF2A FF2Z FF2P px py pz FF2Range charge 1 107 43 0 0 -0 -0 3.15298 43 121 47 0 0 0 0 2.97138 47 1 121 47 0 0 -0 0 2.97565 47 107 43 0 -0 0 -0 3.10325 43 1 97 38 0 0 0 0 3.63527 38 133 52 0 0 0 -0 2.85036 52 1 89 35 0 0 0 0 3.95635 35 141 55 0 -0 -0 -0 2.78145 55 1 90 35 0 0 0 0 3.94515 35 140 55 0 0 -0 -0 2.7865 55 1 95 38 0 -0 -0 -0 3.67254 38 135 52 0 -0 -0 0 2.88728 52 1 119 47 0 0 0 0 2.98623 47 109 43 0 0 0 -0 3.17545 43 1 93 37 0 0 -0 0 3.78905 37 137 53 0 0 -0 -0 2.8152 53 1 129 50 0 -0 -0 0 2.92961 50 101 40 0 0 0 -0 3.46852 40 1 91 36 0 -0 0 0 3.8446 36 138 54 0 0 -0 -0 2.80753 54 1 99 40 0 -0 0 0 3.52113 40 131 50 0 -0 0 -0 2.96041 50 1 89 35 0 -0 -0 -0 3.86209 35 141 55 0 0 -0 0 2.7893 55 1 106 42 0 -0 -0 -0 3.16644 42 123 48 0 -0 -0 0 2.96203 48 1 93 37 0 0 0 0 3.65556 37 137 53 0 0 0 -0 2.81346 53
Ionization and Number of the the electrons produced
I am now running on brems to get the range for each fragments in the gaseous mixture described for 4MeV,8MeV,12MeV,16MeV and 20MeV. I am thinking to get a graph for different fragments ranges as function of the atomic number with error bars.
Brian told me that I am still running the processes in sequence, not becuase of any mistake I did but looks he needs to update the system and work on that point.
Submitting the 50 jobs together failed if I have script that contains all the commands for submitting 50 jobs. Brian and I will work on this to get it done after the system runs my jobs in parallel.
Plot current results using inca and DAQ computer with error bars.
E, Sim X-sect, Measured X-sect, Ratio
4.) Dr. Brey has U-238, can we have it and destroy it?
5.) Solution for making more TGEMs.
Advanced Circuit did the copper TGEMS, will they do another coated with Th-232. I doubt it.
a.) Send CAD drawings to Advanced Cicuits for quotes. A CAD design exists, need to quality control check it, can a vendor read it? Remember copper only around perimeter.
b.) Is there a vendor willing to drill.
Paste then drill. Need to take care of radioactive waste.
I am in process to contact "General product", which cares about milling and CNC machines, I talked to them on the phone to take an appointment(there here in Pocatello) then I will give a report summarizes the meeting and what they do for us.
General Products, 3661 Pole line Rd. , tel: 208-237-2390.
Need to develop method to apply doped paste to circuit board with holes.
Look for plastic plugs to go into the holes.
c.) Paste application method (Printer or brushes)
Order Ink Jet printer which will work with DAQ machine (Unix) then practice.
I am still in process to find an appropriate printer, most of the surface screen printers that I found are for cloth, or even has a special paste that you you should use for the printer. I am also keeping an eye on the website you sent me [44] and there are a new printer there that it might be a choice but I did not get the answers for the questions I sent yet.
- Info about Linx 4100
To answer your questions, this system will come with a manual, and it uses 0.5 liter cleaning solvent and ink cartridges.
The three common ink types are fast dry, which is a methyl ethyl ketone solvent base, ethanol, which is an ethyl alcohol base, and water, which is a simple water base. Please note that the cleaning solvent must match the ink being used.
Also, this system has its own central printing unit, which includes the ink system, controls and display, and does not have the ability to be connected to an external computer; the only ports on it are an external alarm connector and photocell & shaft encoder sockets.
- Info about AMI Presco 465 Compact Screen Printer
This system will come with a manual, and it uses thick film paste-like ink that must be introduced using a plastic spatula.
Further, the squeegee blade in this system should be buttered with some of this ink to eliminate friction between the blade and the screen on the initial pass.
Also, this system has no interface for external PC control, and utilizes onboard microprocessor PLC control.
06/15/10
Quote for HV-PCBoard
the following link for the gerber files sent to the vendor. [45]
Board has been ordered will arrive Monday June 21, 2010
Detector machined
The detector has been machined to house the new HV boards.
called Lloyd
Ultimatum has been given by upper management to get rid of the material.
Call Lloyd (Mobile: 865-206-9663) late Thursday if you don't hear from him. He is gone for 3 weeks after next friday.
TGEM manufacturing
Collet for Milling machine ordered
$54 was paid for a collet which can hold a 1/64" drill bit to drill TGEM holes into FR4. We have at least 2 drill bits.
General Products has been asked to give a quote for producing 10 x 10 cm sized Thick GEM foils. The will build a frame holder for the TGEM boards to hold them while they CNC machine. The boards are thin and flexible needed support from the frame. General products is willing to talk about how they can mill a Thorium doped TGEM.
Simulating the ionization of the fission fragments
Simulated -vs- Experiment X-sect results
Take ratio of measured X-sect/Simulated X-sect and put it in a table
Energy (MeV) | Experimental fission cross section(mb) | Simulated fission cross section(mb) | (Experimental fission cross section/Simulated fission cross section) |
1 | 0.0700 | ||
2 | 2.20 | ||
3 | 2.24 | ||
4 | 2.44 | ||
5 | 2.3 | ||
6 | 1.7 | ||
7 | 1.2 | ||
8 | 1 | ||
9 | 0.97 | ||
10 | 0.99 | ||
11 | 1.03 | ||
12 | 0.95 | ||
13 | 0.89 | ||
14 | 0.79 | ||
15 | 0.72 | ||
16 | 0.60 | ||
17 | 0.68 | ||
18 | 0.66 | ||
19 | 0.64 | ||
20 | 0.54 |
The error estimation is based on the following fission xsection graph:
Find original source for Fission model in GEANT4 and make your own copy which you place in you subdirectory.
- ENDF abbreviations
(n,f): neutron fission reaction, cross section is considering the probability for 1st chance , 2nd chance, ..., n chance fission for the target.
(n,f '): 1st chance neutron fission reaction
For our simulation we consider only the fission reaction of parent ID = 1, so only we are considering first chance fission reaction only.
Fragment ionization
Please look at the following link : [46]Ionization_and_Number_of_the_the_electrons_produced
- The Visit To General Products
the visit was successful in a way that they understood what we want to do, I sent a cad-file, and they sadi that there are able to do it. Also I talked ot him about Th-coated THGEM-plate drilling, he said he will be able basically to do it but he needs to know how are we going to do it and the procedures that we are going to take as radiation protection. He will email me with a quote for the first step, but still he needs to think more about Th-coated ones.
06/28/10
HV board stuffed
The resistors were soldered onto the HV boards.
Below is a picture of the circuit and a measurement of the Voltage acccorss each TGEM as a function of the total voltage.
Now put ONE TGEM card onto the HV circuit and determine the voltage which causes a discharge in Air.
Th-232
Lloyd has found someone to pay for shipping us the Th-232 BUT Dr. Wells has offered 10 g of U-238 for us to use. Dr. Forest will try to meet with him this week to facilitate the transfer. U-238 has 3 times for cross section then Th-232 when neutron energy is between 10 and 15 MeV.
Alan Hunt may still be interested in getting the 1.7 kg material.
TGEM Machining
The 76-drill bit seems to not produce holes in a straight line on the milling machine even though larger drill bit (1/32) did make straight lines. We suspect the drill bit deflects too much when pressure is applied for drilling the hole.
Try to "hole punch" the material before drilling so the drill bit does not move around on the material before it has a chance to start drilling the material.
Simulation
Brems appears to be up try an submit jobs to fill in the X-sect energy gaps.
Then try one energy for U-238.
- Cross section from Simulation
U-238 is a cube 1 x 1 x 1 cm^3.
The number of incident particles per Area =
X-sect =
- barns
(target length was 1 cm)
Add errors to experimental data in table above.
07/26/10
The circuit board is populated and tested, it reaches now to 8 kV without sparking.
The old TGEM foil is also tested, it starts sparking when the voltage reached 400 V on it.
08/1/2010
- TGEM-foil Preparation
FR4 is cut into 11x11 cm, the trial foil has 100 holes, the paste inside the area surrounded by copper (yellow) as in the figure.
8/10/2010
1.) Machine 10 x 10 cm boards so we have 100 holes in a 1.3 x 1.3 cm square array centered on the 10 x 10 cm boards.
3 boards will have resistive paste and 2 will have no paste.
at $20 each we are expecting at least a $100 charge for milling the test boards.
1 10 cm x 10 cm board with a 3.5 mm wide copper outer trace has been made, 4 more are needed.
2.) Search for Panasonic connector samples continues
3.)U-238 articles reporting fission measurements on interlibrary loan.
8/23/2010
1.) 5 , 12 x 12 cm FR4 boards have been etched with a outer copper trace that is 3.5 mm wide. 3 of the boards have been coated with resistive paste. The machine shop will drill 100 holes in each of the 4 boards and treat the 5th board as a spare.
Get a time estimate for drilling holes from Vendor.
Still waiting the quote. expected in the quote: *fixture price. *cost of drilling holes for 100 *cost for drilling all the holes in 10X10 cm *cost of labour
2.) Allied electronics may be willing to sell us 25 connectors. WIP
Quote is sent, $167.88 each for min order of 25 and both connectors, 25 connector pairs for $350. 2-3 weeks delivery.
3.) Insert paper reference that you received here.
File:Pankratov fxsection Th232 U233 U235 Np237 U238 5-37MeV.pdf
the over all accuracy in the measurements (f_x-section) in the range 5-27MeV was not less that 5 percent, but worse than 10 percent in the range 27-37 MeV.
Use data Thief to make your own version of Figure 6, with you simulation results overlayed, and legend includes reference.
The previous data measurements only seem high in the range 20-37 MeV (ref. File:Ignatyyuk U238 nxsetion upto150MeV.pdf page 5).
Also create Xmgrace version of U-238 X-sect with your simulation result and the red line average from above overlayed.
What is mistake for E=3 MeV U-238 simulation?
4.) Drill holes into the TGEM chamber to mount the HV boards
5.) Simulation Cross Section
What is the Format of the the cross-section files GEANT4 uses for Fission.
There is not any information online about the format of the files, in addition there are not editable by users, still users can leave a request on the forum! [47]
Are these files stored in
data/G4NDL3.13/Fission/CrossSection
looks that files are saved without any extension.
8/30/2010
1.) Vendor will likely be able to finish the drilling of 100 holes in 4 FR4 plates 2 weeks after the quote is accepted. A fixture will need to be built to hold the FR4 boards in order to drill the holes at the same location on each board.
2.) Allied electronics may be willing to sell us 25 connectors. WIP
Quote is sent, $167.88 each for min order of 25 and both connectors, 25 connector pairs for $350. 2-3 weeks delivery.
3.) Insert paper reference that you received here.
File:Pankratov fxsection Th232 U233 U235 Np237 U238 5-37MeV.pdf
the over all accuracy in the measurements (f_x-section) in the range 5-27MeV was not less that 5 percent, but worse than 10 percent in the range 27-37 MeV.
Use data Thief to make your own version of Figure 6, with you simulation results overlayed, and legend includes reference.
The previous data measurements only seem high in the range 20-37 MeV (ref. File:Ignatyyuk U238 nxsetion upto150MeV.pdf page 5).
Also create Xmgrace version of U-238 X-sect with your simulation result and the red line average from above overlayed.
What is mistake for E=3 MeV U-238 simulation? Number was from wrong file, pilot error.
4.) Drill holes into the TGEM chamber to mount the HV boards
not done, starts working together as soon as the plates ready.
5.) Simulation Cross Section
New simulation for U-238 under new conditions. but still the simulation is running
I changed the N02SteppingVerbose in a way that can record all fission fragments properties for the 1st, second and third fission reaction for a certain incident neutron energy:
if(NumberOfFissionFragments>0 && fTrack->GetDefinition()->GetAtomicMass()<228 && fTrack->GetDefinition()->GetAtomicMass()>2 && fTrack->GetCurrentStepNumber()==1 && (fTrack->GetParentID()==1 || fTrack->GetParentID()==2 || fTrack->GetParentID()==3))
09/02/10
- RETGEM Preparation
TGEM plate is is prepared as the picture shows below, then covered with resistive paste.
- Sparking Test
A single TGEM plate was installed into the ionization chamber and a voltage was applied across the top and bottom of the plate. Sparks were observed when the voltage difference between the top and bottom of the resistive plate reached 2.8 kV. The sparks appeared to be localized to one of the holes. I will take the plate out and try to clean the hole further by filing away resistive paste around the hole. For comparison, the same foil didn't spark until a voltage difference of 7 kV was reached in air. According to Figure 14 in Media:Jinst8_02_p02012_THGEM_spark.pdf , a voltage difference of 1550 Volts was needed in the Double RTGEM configuration to achieve a gain less than 10^4. Our goal is a gain of 10^6 using 3 RTGEM plates. This suggests we should try to reach high voltage differences of at least 2 kV on each plate without sparking.
Sparking test had been done as the detector have air, the highest source voltage recorded was 7 kV. The detector filled with Ar-gas, the highest source voltage detected was 2.8 kV. There is a specific hole that the spark is on, then at around 5 kV it starts to spread around the hole.
An order of needle files will reach tomorrow, another sparking test will be done tomorrow after cleaning the holes and adding more paste.
Do not add more resistive paste yet.
Insert the density of copper and the density of the resistive paste here in the wiki.
RETGEM vs. THCOBRA
RETGEM | THCOBRA |
Comparison ENDF evaluation of U-238 neutron fission xsection and GEANT4
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
Ref. number | inxn | data description | author | citation | notes |
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 |
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 |
Done In April (edited by 04/30/10)
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:
a- Voltage is applied on the the foil to check the first sparking place.
b- Applying the paste carefully on the area between the holes with very small quantities.
- 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.
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.
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!
2.)Final touches on the HV-circuit are done, diagrams are done by eagle with Gerber files, the chamber is ready for redesigning.
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).
4.)Tracking the process to get Th-232, contacting other vendors for radioactive isotopes, trying to get low cost ones.
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.
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.
AFCRD Reports
- 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.
- 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.
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.
Th-232 and U-238 Activity in mCi
General information:
Physical properties | U-238 | Th-232 |
Half life in years | 4.468 X 10^9 | 1.405 X 10^10 |
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
References
Simulations_of_Particle_Interactions_with_Matter
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://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[48]
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
GEANT4_Paticles_Models[49]
Resistors online store : http://www.justradios.com/rescart.html
RETGEMs
Media:Jinst8_02_p02012_THGEM_spark.pdf
Thick GEM COBRA:
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
Thick_GEM_versus_thin_GEM_in_two_phase_argon_avalanche_detectors (HV circuit)[50]
Stainless Steel deflection [51]
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
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
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
http://www.ellsworth.com/conformal.html?tab=Products
http://www.ellsworth.com/display/productdetail.html?productid=764&Tab=Products
http://www.ellsworth.com/display/productdetail.html?productid=2067&Tab=Products
http://www.cotronics.com/vo/cotr/ea_electricalresistant.htm
b.) mix with a metal similar to Th-232.
c.) construct bed of 0.4 mm nails. Look for 0.4 mm diameter pins.
7/31/2009
New vendor for carbon paste.
http://www.electrapolymers.com/productItem.asp?id=33
The data sheet does not show any information about the thickness of the paste.
The company has a distributor in the usa (877)-867-9668. A phone call is expected on Sat. 8/3/2009 about the availability of the product.
TGEM Mask Design
Coating U-238 or Th-232 is essential for neutron detection in the range 2-14 MeV, but THGEM contains holes that should be protected from any coating material. So, a mask is designed to cover these holes. The holes are in drilled to be on the corners of hexagonal of 1mm side length as in the figure:
The mask is made of stainless steel, 10 um laser tolerance with cut the plate to get the shape in the figure:
Please look at the following files for more details:
Make number bold black font. Add color so it is clear that they are holes in a material.
Vendor
Thick Film Screen Printers
http://www.sciquip.com/browses/browse_Cat.asp?Category=Screen+Printers