Difference between revisions of "PbBi THickness GaussBeam"

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  Use Gaussian to make a incident uniform beam that is 1 cm in diameter and has a beam sigma of 1 cm , then cut out the beam to have a 0.5 cm circular radius.
 
  Use Gaussian to make a incident uniform beam that is 1 cm in diameter and has a beam sigma of 1 cm , then cut out the beam to have a 0.5 cm circular radius.
  
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for electrons
 
for electrons
 +
 +
 +
Dmitry's processing of Tony's GEANT simulations showing transverse phase space portrait (left) and longitudinal phase space portrait (right). Phase space portraits show coordinate x or y vs
 +
diveregense=px/pz or py/pz (or time vs kinetic energy ). Captions show:
 +
 +
1. geometric (not normalized) emittance for transverse and emittance for longitudinal phase space portraits (ellipse areas divided by "pi")
 +
 +
2. Twiss parameters
 +
 +
3. Ellipse centroid for longitudinal phase portrait
 +
 +
4. sqrt(beta*emittance) and sqrt(gamma*emittance) - half sizes of the projections of the ellipses on the coordinate and divergence axes respectively.
 +
 +
Electrons - RMS
 +
 +
[[File:Ed1.png| 400 px]]
 +
 +
Electrons - 68.2% core
 +
 +
[[File:Ed2.png| 400 px]]
 +
 +
Positrons - RMS
 +
 +
[[File:Pd1.png| 400 px]]
 +
 +
Positrons - 68.2% core
 +
 +
[[File:Pd2.png| 400 px]]
  
  
 
[[G4Beamline_PbBi#Target_thickness_optimization]]
 
[[G4Beamline_PbBi#Target_thickness_optimization]]

Latest revision as of 17:53, 9 December 2015

Use Gaussian to make a incident uniform beam that is 1 cm in diameter and has a beam sigma of 1 cm , then cut out the beam to have a 0.5 cm circular radius.


First simple test is to send 1 million, 10 MeV electrons towards a PbBi target and count how many positrons leave the downstream side

The Random number seed is set by Time in G4beamline to use a different set of pseudo random numbers each time it is run

The G4Beamlin incident electron beam has the following properties

beam gaussian particle=e- nEvents=1000000 beamZ=0.0 
        sigmaX=1.0 sigmaY=1.0 sigmaXp=0.100 sigmaYp=0.100 
        meanMomentum=10.0 sigmaP=4.0 meanT=0.0 sigmaT=0.0


-
PbBi Thickness (mm) #positrons/million electrons (G4Beamline) #positrons/million electrons (MCNPX)
1 960,874, 916,934,897=916 +/- 33 1091
1.5 1508 1728
2 1963,1919,1880,1877,1970 = 1902 [math]\pm[/math] 43 1984
2.5 1997 2062
3 2233,2250, 2251,2226 , 2222=2236 [math]\pm[/math] 13 1986
3.5 2193 1938
4 2184,2156,2089,2173,2181=2157 [math]\pm[/math] 39 1858
5 2042 1646
6 1851, 1932, 1857, 1896,1924 = 1892[math] \pm[/math] 37 1541
10 1480,1488 1216

Comparison of G4Beamline and MCNPX


Comparison.png


Energy Distribution

TF PosE 04-28-15.png Positrons2.png

Angular distribution of positrons

TF Theta 04-28-15.png


I was unable to do anything other than a gaussian beam right now, I will try to do one later

For now I have a gaussian with an 8mm RMS and 10 MeV incident electrons as shown below.

The positron and electron momentum distributions after the PbBi converter are shown below


4-30-2015 PositronMomentum 2mm.png4-30-2015 ElectronMomentum 2mm.png

A comma delimited text file with the above events in the format of

x,y,z,Px,Py,Pz

in units of cm for distance and MeV for momentum is located at

for positrons

http://www2.cose.isu.edu/~foretony/Positrons_2mm10MeV.dat


and

http://www2.cose.isu.edu/~foretony/Electrons_2mm10MeV.dat


for electrons

For now I have a gaussian with an 1mm RMS and 10 MeV incident electrons as shown below.

4-30-2015 BeamPosDelta.png4-30-2015 ElectronMomentum.png


The positron and electron momentum distributions after the PbBi converter are shown below


4-30-2015 PositronMomentum 2mmDelta.png4-30-2015 ElectronMomentum 2mmDelta.png

A comma delimited text file with the above events in the format of

x,y,z,Px,Py,Pz

in units of cm for distance and MeV for momentum is located at

for positrons

http://www2.cose.isu.edu/~foretony/Positrons_2mm10MeVDelta.dat


and

http://www2.cose.isu.edu/~foretony/Electrons_2mm10MeVDelta.dat


for electrons


Dmitry's processing of Tony's GEANT simulations showing transverse phase space portrait (left) and longitudinal phase space portrait (right). Phase space portraits show coordinate x or y vs diveregense=px/pz or py/pz (or time vs kinetic energy ). Captions show:

1. geometric (not normalized) emittance for transverse and emittance for longitudinal phase space portraits (ellipse areas divided by "pi")

2. Twiss parameters

3. Ellipse centroid for longitudinal phase portrait

4. sqrt(beta*emittance) and sqrt(gamma*emittance) - half sizes of the projections of the ellipses on the coordinate and divergence axes respectively.

Electrons - RMS

Ed1.png

Electrons - 68.2% core

Ed2.png

Positrons - RMS

Pd1.png

Positrons - 68.2% core

Pd2.png


G4Beamline_PbBi#Target_thickness_optimization