Difference between revisions of "LaserComptonScat"

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  Case-d) <math>E_{electron}</math>=20 MeV, <math>E_{\gamma}</math>=105 eV, process="Compton", #events: 2,000,000'''
 
  Case-d) <math>E_{electron}</math>=20 MeV, <math>E_{\gamma}</math>=105 eV, process="Compton", #events: 2,000,000'''
−
               Result=0 interactions'''
+
               Result= 12 interactions'''
  
 
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Revision as of 20:26, 16 April 2008

Notes on Syed's GEANT4 project for Laser Compton Scattering at the IAC

2/7/08

Step 1: Configure Event generator in which electron parameters can be changes. Move the source left and right of the center. Change is momentum direction; going left and going right.

Step 2: comment out electron and add gamma. get it to move in the same way.

Step 3: turn them both on

Step 4: if fail then find references on event Generator with 2 intersecting beams, perhaps ILC, LHC or BaBar has one.

2/14/08

Problem last week was due to editing the wrong file.

We now have a event generator which starts an electron and a photon moving toward eachother.

We see and event when the photon energy is 500 keV and only the compton process is turned on.

FirstComptonEvent 2-14-08.jpg

Next step:

1.) edit the Stepping Verbose so only a Compton event is printed out

2.) add an event counter so we know how many beam triggers are done to get the event( edit SteppingVerbose.h, add a global variable to the class definition)

output : event number, Photon position, Electron position, Photon and Electron initial and final momentum.

3.) Compare output with BDSIM at 500 keV

4.) Insert new physics process for Low Energy Compton

2/28/08

1.) edit the Stepping Verbose so only a Compton event is printed out (done)

2.) add an event counter so we know how many beam triggers are done to get the event( edit SteppingVerbose.h, add a global variable to the class definition)

output : event number, Photon position, Electron position, Photon and Electron initial and final momentum.

3.) Compare output with BDSIM at 500 keV

4.) Insert new physics process for Low Energy Compton (done)

Still need to do 2 &3.

Compare hand calculation of an event or two with GEANT4 output

3/6/08

Goals for last week

1.) Compare hand calculation of an event or two with GEANT4 output

2.) add an event counter so we know how many beam triggers are done to get the event( edit SteppingVerbose.h, add a global variable to the class definition)

output : event number, Photon position, Electron position, Photon and Electron initial and final momentum.


3.) Compare output with BDSIM at 500 keV (BDSIM crashes at this high energy)

Tasks for next week:

1.) How many GEANT4 triggers does it take to get an event when E-gamma = 30 eV

Zero/10^7. However, if I set the E-gamma=300 eV then I see 1819 triggers out of 10 million iterations.

ComptonEvents At 300eV 3-12-08.jpg


2.) remove detector which blocks reactions for 0<Z<200 

   [box]Commented out Sensitive Detector function in DetectorConstruction.cc. I still see the SD in display[/box]

3.) Store tracking info for photon and electron into variables for printing out 

   [box]Show the text file for 300 eV laser and 20 MeV electron[/box]

4.) Compare BDSIM and GEANT4 for E-gamma = 300 or 30 eV 

   [box]BDSIM crashes at 300 eV[/box]

5.) Any measured X-sections for 2 eV Compton? 

   [box]Was not able to find on internet. BDSIM however, uses GEANT4 database...We might need to dig into their code, I got the source code[/box]

3/13/08

Tasks:

1.) fix output file so electons and photon from same event on same line 

  o Geant4 output.txt:
Variable value
# Triggers 153610
Compton Event # 1
Scattered Photon energy (keV) 0.299784
photon X position 0
photon Y position 0
photon Z position -441.431
photon X Momentum 6.30938e-05
photon Y Momentum 0.000285127
photon Z Momentum -6.77687e-05
Particle ID 22
Scattered e- KE (keV) 0.000215785
Scattered electron X position -177.027
Scattered electron Y position -800
Scattered electron Z position 590.444
Scattered electron X Momentum -6.30938e-05
Scattered electron Y Momentum -0.000285127
Scattered electron Z Momentum 0.000367769
Particle ID 11
[math]\lambda^{\prime} = \lambda + \lambda_C (1-\cos(\theta)) = \frac{2 \pi}{\omega^{\prime}} = \frac{ch}{E_{\gamma}^{\prime}} = \frac{12,400 \mbox{Angstroms}}{E_{\gamma}^{\prime}}[/math]
[math]\lambda_C[/math] = electron compton wavelength = [math]\frac{h}{m_ec} = 2.43 \times 10^{-12} m[/math]
[math]E_k = \hbar \omega \frac{\lambda_C}{\lambda} \frac{1- \cos(\theta)}{1 + \frac{\lambda_C}{\lambda} \left (1 - \cos(\theta) \right )}[/math] = electron final kinetic energy
[math]\phi = \cot \left [ \left ( 1+ \frac{\lambda_C}{\lambda}\right ) tan(\frac{\theta}{2}\right ][/math] = ejected electron angle w.r.t original photon direction
     15361 ||   1   || 0.299784   0   0   -441.431   6.30938e-05   0.000285127   -6.77687e-05   22   0.000215785   -177.027   -800   590.444   -6.30938e-05 -0.000285127   0.000367769   11   
    32685.8   2   0.299791   0   0   -131.765   -7.34024e-05   0.000285186   -5.61732e-05   22   0.000208981   192.024   -746.061   800   7.34024e-05   -0.000285186   0.000356173   11   
    33535.9   3   0.299682   0   0   -754.315   -0.000175966   -1.63899e-05   -0.000242026   22   0.000318029   504.599   46.9997   800   0.000175966   1.63899e-05   0.000542026   11   
      34157   4   0.299864   0   0   -579.415   -7.39129e-05   -0.000282637   6.7614e-05   22   0.00013635   209.21   800   78.3512   7.39129e-05   0.000282637   0.000232386   11

. . . .

2.)Compare compton scattering between BDSIM and GEANT4 for 300 eV photon incident on a 20 MeV electron

BDSIM GEANT4
Compton BDSIM Events At 300eV 3-19-08.jpg Compton Geant4 Events At 300eV 3-19-08.jpg 
o BDSIM (5,000,000 Iterations):



  Anglex BDSIM Events At 300eV 3-19-08.jpg
  Angley BDSIM Events At 300eV 3-19-08.jpg
  Momx BDSIM Events At 300eV 3-19-08.jpg
  Momy BDSIM Events At 300eV 3-19-08.jpg   
  Posz BDSIM Events At 300eV 3-19-08.jpg 

o Geant4 (5,000,000 iterations):



  Compton posx Geant4 Events At 300eV 3-19-08.jpg
  Compton posy Geant4 Events At 300eV 3-19-08.jpg
  Compton posz Geant4 Events At 300eV 3-19-08.jpg
 Electron Geant4 Events At 300eV 3-19-08.jpg
Compton momx Geant4 Events At 300eV 3-19-08.jpg
  Compton momy Geant4 Events At 300eV 3-19-08.jpg
  Compton momz Geant4 Events At 300eV 3-19-08.jpg
 
  Electron posx Geant4 Events At 300eV 3-19-08.jpg
  Electron posy Geant4 Events At 300eV 3-19-08.jpg
  Electron posz Geant4 Events At 300eV 3-19-08.jpg
  Electron momx Geant4 Events At 300eV 3-19-08.jpg
  Electron momy Geant4 Events At 300eV 3-19-08.jpg
  Electron momz Geant4 Events At 300eV 3-19-08.jpg


3.) remove physics processes and run 10^9 events piece mealed so you save event generator seed every 10^8 

o Still waiting for run_0.rndm, run_1.rndm...., files on inca. Process at the moment is executing!

3/20/08

Taks for next week

1.) Check elastic kinematics of LowEnergyCompton for case where electron is 1 eV and incident photon ranges between 300 ev and 8 keV 

output.txt for 1 eV electron and 8 keV gamma. Number of iterations: 1,000,000
Variable LowEnCompton_value Compton_value
# Triggers 53 48
Compton Event # 2 2
Scattered Photon energy (keV) 7.79307 7.76672
photon X position 0 0
photon Y position 0 0
photon Z position -752.482 -751.601
photon X Momentum -0.0050576 0.00228733
photon Y Momentum 0.00239243 -0.00204773
photon Z Momentum -0.00542483 -0.0071342
Particle ID 22 22
Scattered e- KE (keV) 0.206934 0.233283
Scattered electron X position 584.874 -234.503
Scattered electron Y position -276.667 209.94
Scattered electron Z position 800 800
Scattered electron X Momentum 0.0050576 -0.00228733
Scattered electron Y Momentum -0.00239243 0.00204773
Scattered electron Z Momentum 0.0134248 0.0151342
Particle ID 11 11

o Plots

GEANT4_LowEnCompton, 8 keV incoming Photons GEANT4_Compton, 8 keV incoming Photons
LowEnCompton At 1eVelectron 8keVphoton 4-06-08a.jpg Compton At 1eVelectron 8keVphoton 4-06-08a.jpg
GEANT4_LowEnCompton, 1 eV incoming Electrons GEANT4_Compton, 1 eV incoming Electrons
LowEnCompton At 1eVelectron 8keVphoton 4-06-08b.jpg Compton At 1eVelectron 8keVphoton 4-06-08b.jpg 
  output.txt for 1 eV electron and 300 eV gamma. Number of iterations: 2,000,000
Variable LowEnCompton_value Compton_value
# Triggers 32685 7123
Compton Event # 2 2
Scattered Photon energy (keV) 0.299791 0.299745
photon X position 0 0
photon Y position 0 0
photon Z position -131.765 554.105
photon X Momentum -7.34024e-05 0.000261431
photon Y Momentum 0.000285186 5.7275e-05
photon Z Momentum -5.61732e-05 -0.000134982
Particle ID 22 22
Scattered e- KE (keV) 0.000208981 0.000255222
Scattered electron X position 192.024 -147.787
Scattered electron Y position -746.061 -32.3775
Scattered electron Z position 800 800
Scattered electron X Momentum 7.34024e-05 -0.000261431
Scattered electron Y Momentum -0.000285186 -5.7275e-05
Scattered electron Z Momentum 0.000356173 0.000434982
Particle ID 11 11

o Plots

GEANT4_LowEnCompton, 300 eV incoming Photons GEANT4_Compton, 300 eV incoming Photons
LowEnCompton At 1eVelectron 300eVphoton 4-09-08a.jpg Compton At 1eVelectron 300eVphoton 4-09-08a.jpg
GEANT4_LowEnCompton, 1 eV incoming Electrons GEANT4_Compton, 1 eV incoming Electrons
LowEnCompton At 1eVelectron 300eVphoton 4-09-08b.jpg Compton At 1eVelectron 300eVphoton 4-09-08b.jpg 


see if #triggers is same as above when [math]E_{\gamma}[/math] = 800 eV and [math]E_{e}[/math] = 1 eV

2.) Same as above except now change the incident electron energy up to 20 MeV, 50 ev, 1 keV, 10 keV, 1Mev, 10 MeV 

output.txt for 20 MeV electron and 300 eV gamma. Number of Iterations: 2,000,000
Variable LowEnCompton_value Compton_value
# Triggers 32685 7123
Compton Event # 2 2
Scattered Photon energy (keV) 0.299791 0.299745
photon X position 0 0
photon Y position 0 0
photon Z position -131.765 554.105
photon X Momentum -7.34024e-05 0.000261431
photon Y Momentum 0.000285186 5.7275e-05
photon Z Momentum -5.61732e-05 -0.000134982
Particle ID 22 22
Scattered e- KE (keV) 0.000208981 0.000255222
Scattered electron X position 192.024 -147.787
Scattered electron Y position -746.061 -32.3775
Scattered electron Z position 800 800
Scattered electron X Momentum 7.34024e-05 -0.000261431
Scattered electron Y Momentum -0.000285186 -5.7275e-05
Scattered electron Z Momentum 0.000356173 0.000434982
Particle ID 11 11

o Plots

GEANT4_LowEnCompton, 300 eV incoming Photons GEANT4_Compton, 300 eV incoming Photons
LowEnCompton At 20MeVelectron 300eVphoton 4-09-08a.jpg Compton At 20MeVelectron 300eVphoton 4-09-08a.jpg
GEANT4_LowEnCompton, 20 MeV incoming Electrons GEANT4_Compton, 20 MeV incoming Electrons
LowEnCompton At 20MeVelectron 300eVphoton 4-09-08b.jpg Compton At 20MeVelectron 300eVphoton 4-09-08b.jpg


4/10/08

1.) check if cross section is same fore 100 eV < [math]E_{gamma}[/math] <800 eV 

Case-a) [math]E_{electron}[/math]=20 MeV, [math]E_{\gamma}[/math]=100 eV, process="LowEnCompton", #events: 2,000,000
              Result=0 interactions



Case-b) [math]E_{electron}[/math]=20 MeV, [math]E_{\gamma}[/math]=100 eV, process="Compton", #events: 2,000,000
              Result=0 interactions

Case-c) [math]E_{electron}[/math]=20 MeV, [math]E_{\gamma}[/math]=105 eV, process="LowEnCompton", #events: 2,000,000
              Result=0 interactions



Case-d) [math]E_{electron}[/math]=20 MeV, [math]E_{\gamma}[/math]=105 eV, process="Compton", #events: 2,000,000
              Result= 12 interactions
Variable LowEnCompton_value (case-c) Compton_value (case-d)
# Triggers 490155
Compton Event # 2
Scattered Photon energy (keV) 0.104974
photon X position 0 0
photon Y position 0 0
photon Z position -521.846
photon X Momentum 2.94637e-05
photon Y Momentum -9.85919e-05
photon Z Momentum -2.07632e-05
Particle ID 22 22
Scattered e- KE (keV) 2.58365e-05
Scattered electron X position -239.076
Scattered electron Y position 800
Scattered electron Z position 498.63
Scattered electron X Momentum -2.94637e-05
Scattered electron Y Momentum 9.85919e-05
Scattered electron Z Momentum 0.000125763
Particle ID 11 11

o Plots

GEANT4_LowEnCompton, 8 keV incoming Photons GEANT4_Compton, 8 keV incoming Photons
LowEnCompton At 1eVelectron 8keVphoton 4-06-08a.jpg Compton At 1eVelectron 8keVphoton 4-06-08a.jpg
GEANT4_LowEnCompton, 1 eV incoming Electrons GEANT4_Compton, 1 eV incoming Electrons
LowEnCompton At 1eVelectron 8keVphoton 4-06-08b.jpg Compton At 1eVelectron 8keVphoton 4-06-08b.jpg 
  output.txt for 1 eV electron and 300 eV gamma. Number of iterations: 2,000,000
Variable LowEnCompton_value Compton_value
# Triggers 32685 7123
Compton Event # 2 2
Scattered Photon energy (keV) 0.299791 0.299745
photon X position 0 0
photon Y position 0 0
photon Z position -131.765 554.105
photon X Momentum -7.34024e-05 0.000261431
photon Y Momentum 0.000285186 5.7275e-05
photon Z Momentum -5.61732e-05 -0.000134982
Particle ID 22 22
Scattered e- KE (keV) 0.000208981 0.000255222
Scattered electron X position 192.024 -147.787
Scattered electron Y position -746.061 -32.3775
Scattered electron Z position 800 800
Scattered electron X Momentum 7.34024e-05 -0.000261431
Scattered electron Y Momentum -0.000285186 -5.7275e-05
Scattered electron Z Momentum 0.000356173 0.000434982
Particle ID 11 11

o Plots

GEANT4_LowEnCompton, 300 eV incoming Photons GEANT4_Compton, 300 eV incoming Photons
LowEnCompton At 1eVelectron 300eVphoton 4-09-08a.jpg Compton At 1eVelectron 300eVphoton 4-09-08a.jpg
GEANT4_LowEnCompton, 1 eV incoming Electrons GEANT4_Compton, 1 eV incoming Electrons
LowEnCompton At 1eVelectron 300eVphoton 4-09-08b.jpg Compton At 1eVelectron 300eVphoton 4-09-08b.jpg 


see if #triggers is same as above when [math]E_{\gamma}[/math] = 800 eV and [math]E_{e}[/math] = 1 eV


2.) Create your own Physics list subroutine called SyedCompton which is a renamed copy of LowEnergyCompton

3.) After SyedCompton runs, change it so the final electron kinetic energy is calculated correctly.

4.) Look up relativistic Lorentz transformation to boost to electron rest frame. A fair start is at http://www.iac.isu.edu/mediawiki/index.php/Forest_Relativity_Notes#Lorentz_Transformations

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