LaserComptonScat

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.

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.

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

o BDSIM (5,000,000 Iterations):

o Geant4 (5,000,000 iterations):

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

GEANT4_LowEnCompton, 1 eV incoming Electrons	GEANT4_Compton, 1 eV incoming Electrons

  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

GEANT4_LowEnCompton, 1 eV incoming Electrons	GEANT4_Compton, 1 eV incoming Electrons

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

GEANT4_LowEnCompton, 20 MeV incoming Electrons	GEANT4_Compton, 20 MeV incoming Electrons

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 interaction

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

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
photon Y position		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, 105 eV incoming Photons	GEANT4_Compton, 105 eV incoming Photons
400 px

GEANT4_LowEnCompton, 20 MeV incoming Electrons	GEANT4_Compton, 20 MeV incoming Electrons
400 px

Case-e) [math]E_{electron}[/math]=20 MeV, [math]E_{\gamma}[/math]=150 eV, process="LowEnCompton", #events: 2,000,000
              Result=0 interaction

Case-f) [math]E_{electron}[/math]=20 MeV, [math]E_{\gamma}[/math]=150 eV, process="Compton", #events: 2,000,000
              Result= 93 interactions

Variable	LowEnCompton_value (case-e)	Compton_value (case-f)
# Triggers		36600
Compton Event #		2
Scattered Photon energy (keV)		0.149994
photon X position		0
photon Y position		0
photon Z position		331.001
photon X Momentum		-6.9277e-05
photon Y Momentum		-2.37144e-05
photon Z Momentum		0.000130907
Particle ID	22	22
Scattered e- KE (keV)		5.60297e-06
Scattered electron X position		800
Scattered electron Y position		273.85
Scattered electron Z position		551.485
Scattered electron X Momentum		6.9277e-05
Scattered electron Y Momentum		2.37144e-05
Scattered electron Z Momentum		1.9093e-05
Particle ID	11	11

o Plots

GEANT4_LowEnCompton, 150 eV incoming Photons	GEANT4_Compton, 150 eV incoming Photons
400 px

GEANT4_LowEnCompton, 20 MeV incoming Electrons	GEANT4_Compton, 20 MeV incoming Electrons
400 px

Case-g) [math]E_{electron}[/math]=20 MeV, [math]E_{\gamma}[/math]=200 eV, process="LowEnCompton", #events: 2,000,000
              Result=0 interaction

Case-h) [math]E_{electron}[/math]=20 MeV, [math]E_{\gamma}[/math]=200 eV, process="Compton", #events: 2,000,000
              Result=  179 interactions

Variable	LowEnCompton_value (case-g)	Compton_value (case-h)
# Triggers		33713
Compton Event #		2
Scattered Photon energy (keV)		0.19991
photon X position		0
photon Y position		0
photon Z position		778.343
photon X Momentum		7.46479e-05
photon Y Momentum		0.000183052
photon Z Momentum		-2.97293e-05
Particle ID	22	22
Scattered e- KE (keV)		8.98786e-05
Scattered electron X position		-7.03722
Scattered electron Y position		-17.2567
Scattered electron Z position		800
Scattered electron X Momentum		-7.46479e-05
Scattered electron Y Momentum		-0.000183052
Scattered electron Z Momentum		0.000229729
Particle ID	11	11

o Plots

GEANT4_LowEnCompton, 200 eV incoming Photons	GEANT4_Compton, 200 eV incoming Photons
400 px

GEANT4_LowEnCompton, 20 MeV incoming Electrons	GEANT4_Compton, 20 MeV incoming Electrons
400 px

Case-i) [math]E_{electron}[/math]=20 MeV, [math]E_{\gamma}[/math]=400 eV, process="LowEnCompton", #events: 2,000,000
              Result= 697 interaction

Case-j) [math]E_{electron}[/math]=20 MeV, [math]E_{\gamma}[/math]=400 eV, process="Compton", #events: 2,000,000
              Result= 898 interactions

Variable	LowEnCompton_value (case-i)	Compton_value (case-j)
# Triggers	6012	5318
Compton Event #	2	2
Scattered Photon energy (keV)	0.399439	0.399849
photon X position	0	0
photon Y position	0	0
photon Z position	233.061	760.793
photon X Momentum	-0.000130127	1.38275e-06
photon Y Momentum	0.000205697	0.000341899
photon Z Momentum	-0.000316714	0.000207322
Particle ID	22	22
Scattered e- KE (keV)	0.000560591	0.000150707
Scattered electron X position	102.933	-0.281371
Scattered electron Y position	-162.712	-69.5718
Scattered electron Z position	800	800
Scattered electron X Momentum	0.000130127	-1.38275e-06
Scattered electron Y Momentum	-0.000205697	-0.000341899
Scattered electron Z Momentum	0.000716714	0.000192678
Particle ID	11	11

o Plots

GEANT4_LowEnCompton, 400 eV incoming Photons	GEANT4_Compton, 400 eV incoming Photons

GEANT4_LowEnCompton, 20 MeV incoming Electrons	GEANT4_Compton, 20 MeV incoming Electrons

Case-k) [math]E_{electron}[/math]=20 MeV, [math]E_{\gamma}[/math]=800 eV, process="LowEnCompton", #events: 2,000,000
              Result= 2534 interactions

Case-l) [math]E_{electron}[/math]=20 MeV, [math]E_{\gamma}[/math]=800 eV, process="Compton", #events: 2,000,000
              Result= 3314 interactions

Variable	LowEnCompton_value (case-k)	Compton_value (case-l)
# Triggers	2033	1703
Compton Event #	2	2
Scattered Photon energy (keV)	0.798489	0.799399
photon X position	0	0
photon Y position	0	0
photon Z position	302.879	759.113
photon X Momentum	0.000776101	-0.000120116
photon Y Momentum	-8.6914e-05	-0.000672133
photon Z Momentum	-0.00016643	0.000415751
Particle ID	22	22
Scattered e- KE (keV)	0.00151064	0.000600626
Scattered electron X position	-399.218	12.7812
Scattered electron Y position	44.7076	71.5199
Scattered electron Z position	800	800
Scattered electron X Momentum	-0.000776101	0.000120116
Scattered electron Y Momentum	8.6914e-05	0.000672133
Scattered electron Z Momentum	0.00096643	0.000384249
Particle ID	11	11

o Plots

GEANT4_LowEnCompton, 800 eV incoming Photons	GEANT4_Compton, 800 eV incoming Photons

GEANT4_LowEnCompton, 20 MeV incoming Electrons	GEANT4_Compton, 20 MeV incoming Electrons

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

Created local SyedLowEnergyCompton and SyedCompton subroutines:

Case-m) [math]E_{electron}[/math]=20 MeV, [math]E_{\gamma}[/math]=800 eV, process="LowEnCompton", #events: 2,000,000
              Result= 2534 interactions

Case-n) [math]E_{electron}[/math]=20 MeV, [math]E_{\gamma}[/math]=800 eV, process="Compton", #events: 2,000,000
              Result= 3314 interactions

Variable	SyedLowEnCompton_value (case-m)	SyedCompton_value (case-n)
# Triggers	2033	1703
Compton Event #	2	2
Scattered Photon energy (keV)	0.798489	0.799399
photon X position	0	0
photon Y position	0	0
photon Z position	302.879	759.113
photon X Momentum	0.000776101	-0.000120116
photon Y Momentum	-8.6914e-05	-0.000672133
photon Z Momentum	-0.00016643	0.000415751
Particle ID	22	22
Scattered e- KE (keV)	0.00151064	0.000600626
Scattered electron X position	-399.218	12.7812
Scattered electron Y position	44.7076	71.5199
Scattered electron Z position	800	800
Scattered electron X Momentum	-0.000776101	0.000120116
Scattered electron Y Momentum	8.6914e-05	0.000672133
Scattered electron Z Momentum	0.00096643	0.000384249
Particle ID	11	11

o Plots

GEANT4_SyedLowEnCompton, 800 eV incoming Photons	GEANT4_SyedCompton, 800 eV incoming Photons

GEANT4_SyedLowEnCompton, 20 MeV incoming Electrons	GEANT4_SyedCompton, 20 MeV incoming Electrons

4/17/08

1.) Lower cutoff energy and redo rate plots from previous week. Created local SyedLowEnergyCompton and SyedCompton subroutines:

Case-a) [math]E_{electron}[/math]=20 MeV, [math]E_{\gamma}[/math]=2.326 eV, process="LowEnCompton", #events: 2,000,000
              lowEnergyLimit(2*eV)
              intrinsicLowEnergyLimit(1*eV)
              Result=  270 interactions

Case-b) [math]E_{electron}[/math]=20 MeV, [math]E_{\gamma}[/math]=2.326 eV, process="Compton", #events: 2,000,000
              lowEnergyLimit(2*eV)
              Result= 0 interactions

Variable	SyedLowEnCompton_value (case-a)	SyedCompton_value (case-b)
# Triggers	18955
Compton Event #	2	2
Scattered Photon energy (keV)	0.002326
photon X position	0	0
photon Y position	0	0
photon Z position	601.57
photon X Momentum	-6.4311e-10
photon Y Momentum	-9.36186e-10
photon Z Momentum	2.326e-06
Particle ID	22	22
Scattered e- KE (keV)	1.26208e-15
Scattered electron X position	549.557
Scattered electron Y position	800
Scattered electron Z position	601.807
Scattered electron X Momentum	6.43062e-10
Scattered electron Y Momentum	9.36116e-10
Scattered electron Z Momentum	2.77288e-13
Particle ID	11	11

o Plots

GEANT4_SyedLowEnCompton, 2.326 eV incoming Photons	GEANT4_SyedCompton, 2.326 eV incoming Photons
	400 px

GEANT4_SyedLowEnCompton, 20 MeV incoming Electrons	GEANT4_SyedCompton, 20 MeV incoming Electrons
	400 px

Case-c) [math]E_{electron}[/math]=20 MeV, [math]E_{\gamma}[/math]=2.326 eV, process="LowEnCompton", #events: 2,000,000
              lowEnergyLimit(2*eV)
              intrinsicLowEnergyLimit(0.1*eV)
              Result=  270 interactions

Case-d) [math]E_{electron}[/math]=20 MeV, [math]E_{\gamma}[/math]=2.326 eV, process="LowEnCompton", #events: 5,000,000
              lowEnergyLimit(2*eV)
              intrinsicLowEnergyLimit(0.1*eV)
              Result=  636 interactions

Variable	SyedLowEnCompton_value (case-c)	SyedLowEnCompton_value (case-d)
# Triggers	18955	18955
Compton Event #	2	2
Scattered Photon energy (keV)	0.002326	0.002326
photon X position	0	0
photon Y position	0	0
photon Z position	601.57	601.57
photon X Momentum	-6.4311e-10	-6.4311e-10
photon Y Momentum	-9.36186e-10	-9.36186e-10
photon Z Momentum	2.326e-06	2.326e-06
Particle ID	22	22
Scattered e- KE (keV)	1.26208e-15	1.26208e-15
Scattered electron X position	549.557	549.557
Scattered electron Y position	800	800
Scattered electron Z position	601.807	601.807
Scattered electron X Momentum	6.43062e-10	6.43062e-10
Scattered electron Y Momentum	9.36116e-10	9.36116e-10
Scattered electron Z Momentum	2.77288e-13	2.77288e-13
Particle ID	11	11

o Plots

GEANT4_SyedLowEnCompton, 2.326 eV incoming Photons(2-million events)	GEANT4_SyedCompton, 2.326 eV incoming Photons (5-million events)

GEANT4_SyedLowEnCompton, 20 MeV incoming Electrons(2-million events)	GEANT4_SyedCompton, 20 MeV incoming Electrons(5-million events)

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

    Final Electron KE is approx. equals to 20MeV in this case because energy lost by incoming electrons is so small following
    Compton interaction as shown in above plots ...suggestions???

4/24/08

1.) Try HeP Lorentz vector class and set vectors within the SyedCompton routine

CLHEP Man

HepLorentzVector P4eLab

P4eLab.setPx(HepDouble);

5/1/08

Got the class

G4LorentzVector* P4eLab;

defined in SyedLowEnergyCompton.hh

Then created the variable

 P4eLab = new G4LorentzVector;

 P4eLab->setPx(1.4596);

 G4cout << "P4e Px= " << P4eLab << G4endl;

in SyedLowEnergyCompton.cc

1.) Check the functionality of the function calls below to see if we understand how they work

P4eLab->setPx(1.4596);
cout << "P4e " << P4eLab << endl;

cout << "rest 4 Vector" << P4eLab.rest4Vector() << endl;---->"These functions are not declared!"
cout << "rest 4 Vector" << P4eLab.rest4Vector().beta << endl;---->"These functions are not declared!"

2.) 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

3.) check out reference

A.A. Sokolov and I.M. Ternov Sov. Phys. Dokl. 8 (1964), p. 1203.

may lead to a reference for our problem.

4.) Install GEANT4 on Brems

   *done* but with graphics option was disabled, there are issues with OpenGL on brems and I was not able to compile MesaGL in my local folder  
  

5.) create 2 sets of 24 random number seed files. The first set of 24 random number seed files will run for 2 hours and the second set will run for 24 hours.

   *Compilation Error message on Brems:*
    Compiling LCS.cc ...
    Using global libraries ...
    Linking LCS ...
    /home/naeesyed/apps/geant4/geant4.9.1.p02/lib/Linux-g++/libG3toG4.so: undefined reference to `G3Division::UpdateVTE()'
    /home/naeesyed/apps/geant4/geant4.9.1.p02/lib/Linux-g++/libG3toG4.so: undefined reference to `G3Division::CreatePVReplica()'
    /home/naeesyed/apps/geant4/geant4.9.1.p02/lib/Linux-g++/libG3toG4.so: undefined reference to `G3Division::G3Division(G3DivType, G3VolTableEntry*,     G3VolTableEntry*, int, int, int, double, double)'
    /home/naeesyed/apps/geant4/geant4.9.1.p02/lib/Linux-g++/libG3toG4.so: undefined reference to `G3Division::G3Division(G3VolTableEntry*, G3VolTableEntry*, G3Division const&)'
    collect2: ld returned 1 exit status
    make: *** [/home/naeesyed/geant4/bin/Linux-g++/LCS] Error 1

6/12/08

1.) using interactive version of LCS test the transformations below

We have proton and electron. In the Lab frame electron is moving along the x-axis with momentum ;[math]\vec{p_e}[/math] and proton is at rest. The 4-vectors are:

Lab Frame

[math]P_e=[/math]([math]E_e[/math],[math]p_e[/math],0,0) and for proton :[math]P_p=[/math]([math]m_p[/math],0,0,0)

CM Frame

:[math]{P_e}^{\prime}=[/math]([math]{E_e}^{\prime}[/math],[math]{p_e}^{\prime}[/math],[math]0[/math],[math]0[/math]) and for proton :[math]{P_p}^{\prime}=[/math]([math]{E_p}^{\prime}[/math],[math]{p_p}^{\prime}[/math],[math]0[/math],[math]0[/math])

Find [math] \beta_{CM} [/math] such that [math]P_{tot}^{CM}=0 =p_e^{\prime} + {p_p}^{\prime}[/math]

[math]\left ( \begin{matrix} {E_e}^{\prime} \\ p_e^{\prime} \\ 0 \\ 0 \end{matrix} \right )= \left [ \begin{matrix} \gamma & -\gamma \beta & 0 & 0 \\ -\gamma \beta & \gamma &0 &0 \\ 0 &0 &1 &0 \\ 0 &0 &0 & 1 \end{matrix} \right ] \left ( \begin{matrix} E_e \\ p_e \\ 0 \\ 0 \end{matrix} \right )[/math]

[math]\left ( \begin{matrix} {E_p}^{\prime} \\ p_p^{\prime} \\ 0 \\ 0 \end{matrix} \right )= \left [ \begin{matrix} \gamma & -\gamma \beta & 0 & 0 \\ -\gamma \beta & \gamma &0 &0 \\ 0 &0 &1 &0 \\ 0 &0 &0 &1\end{matrix} \right ] \left ( \begin{matrix} m_p \\ 0 \\ 0 \\ 0 \end{matrix} \right )[/math]

Using the last two equations we will get the following for x component:

[math]{p_e}^{\prime}=-\gamma_{cm}(\beta_{cm} E_e-p_e)[/math]

[math]p_p^{\prime} = - \gamma_{cm} \beta_{cm} m_p[/math]

[math] \gamma_{cm}(p_e - \beta_{cm} E_e)= \gamma_{cm} \beta_{cm} m_p [/math]

[math]\beta_{cm} = \frac {p_e}{m_p + E_e}[/math]

Example

[math]p_e = 5.736 Gev \sim E_e[/math] : electron mass is neglibible

[math]m_p = 0.938 GeV[/math] : Mass of a proton

[math]\beta_{cm} = \frac{5.736}{6.674} = 0.859 \lt 1[/math]

[math]\gamma_{cm} = \frac{1}{\sqrt{1 - \beta_{cm}^2}} = \frac{1}{\sqrt{1 - 0.859^2}} = 1.9532[/math]

[math]\left ( \begin{matrix} {E_e}^{\prime} \\ p_{ex}^{\prime} \\ p_{ey}^{\prime} \\ p_{ez}^{\prime} \end{matrix} \right )= \left [ \begin{matrix} \gamma_{cm} & 0 & 0 & -\gamma_{cm} \beta_{cm} \\ 0 & 1 &0 &0 \\ 0 &0 &1 &0 \\ -\gamma_{cm} \beta_{cm} &0 &0 &\gamma_{cm}\end{matrix} \right ] \left ( \begin{matrix} E_e=4.4915 \\ -0.549 \\ 0.974 \\ 4.3501 \end{matrix} \right )[/math]

Electron

[math]\left ( \begin{matrix} {E_e}^{\prime} \\ p_{ex}^{\prime} \\ p_{ey}^{\prime} \\ p_{ez}^{\prime} \end{matrix} \right )= \left ( \begin{matrix} 4.4915 \gamma_{cm} - 4.3501 \gamma_{cm} \beta_{cm} \\ -0.549 \\ 0.974 \\ -4.4915 \gamma_{cm} \beta_{cm} + 4.3501 \gamma_{cm} \end{matrix} \right ) = \left ( \begin{matrix} 1.4742 \\ -0.549 \\ 0.974 \\ 0.96078 \end{matrix} \right )[/math]

In our case 4-vectors for particles are

[math](P_e)_\mu = ( 5.736, 0, 0, 5.736 GeV)[/math]
[math](P_p)_\mu = (m_p, 0, 0, 0)[/math]
[math]({P_e}^{\prime})_\mu = (4.4914861, -0.549, 0.974, 4.3501 )[/math]
[math]({P_{\pi^-}}^{\prime})_\mu = (0.575721, 0.1052, -0.4394, 0.3282)[/math]

Compiling on brems

1.) turned off a GUI and G3toG4 stuff

2.) edited $G4INSTALL/config/binmake.gmk and commmented out the VIS variables and include commands

3.) comment out interactive commands in LCS.cc so only batch mode would run

we are compiled now.

Practice submitting batch jobs via ssh command and the random number seed files.

Submitting batch jobs on brems

Concept: While logged into brems you can submit a job to run on bres 3 by using the ssh command via

ssh brems3 source run0.script 

the script "run0.script"

contains all the command you would type interactively in order to execute the program

source ~/apps/geant4/geant4.9.1.p02/env.sh
cd /home/naeesyed/geant4/LCS/Laser_Compton_Backscattering/run0
LCS vis.mac > /dev/null

Khalid has cross sections in his interview talk

[math]\frac{d \sigma}{d \Omega} = \frac{1-\beta^2 }{1-\beta cos \theta} cos^2 \theta cos -\beta[/math]

9/5/08

Insert Transformation matrix to take electron beam in Lab frame to the electron in the electron's rest frame.

Find [math]\beta_R[/math]

[math] \beta_R = \frac {P_e}{E_e + m_e} =\frac {20MeV}{20MeV + 0.511MeV} = 0.975 \lt  1[/math]

[math] \gamma_R = \frac {1}\sqrt{1 - \beta_r^2} =\frac {20MeV}{20MeV + 0.511MeV} = 0.975 \lt  1[/math]

Insert Transformation matrix to transform outgoing X-ray momentum four vector in the Lab from to the electron at rest frame.

Write equation for [math]\theta_R[/math]= angle of the outgoing X-ray in the electron rest frame.

Klein-Nishina Compton Cross Section

Khalid LCS paper:File:Chouffani PhysRevST 050701 2006 pg9.pdf

Questions: Why [math]\theta[/math] and [math]\theta_d[/math] ?