Difference between revisions of "Simulations and Backgrounds"

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# Encode the geometry in GDML, an XML based format that Geant4 reads in.
 
# Encode the geometry in GDML, an XML based format that Geant4 reads in.
 
# Include the Bubble Chamber geometry using the Bubble Chamber STEP file (change .txt to .stp): [[media:BubbleChamber.txt]].
 
# Include the Bubble Chamber geometry using the Bubble Chamber STEP file (change .txt to .stp): [[media:BubbleChamber.txt]].
# A STEP file for the beam line will be ready very soon.
+
# The beamline STEP file will be ready very soon.
 
# GEANT4 uses models that calculate wrong photo–nuclear cross sections (see above). GEANT4 does not allow for user’s cross sections. What to do?
 
# GEANT4 uses models that calculate wrong photo–nuclear cross sections (see above). GEANT4 does not allow for user’s cross sections. What to do?
 
## Use GEANT4 to produce the photon spectra impinging on the superheated liquid.
 
## Use GEANT4 to produce the photon spectra impinging on the superheated liquid.

Revision as of 11:50, 21 May 2014

GEANT4 vs. Experimental Data

  • Benchmarking of monte carlo simulation of bremsstrahlung from thick targets at radiotherapy energies

B. A. Faddegon, M. Asai, J. Perl, C. Ross, J. Sempau, J. Tinslay, and F. Salvat. Med. Phys. 35 (2008) 4308 media:MedPhys.35.4308.pdf


GEANT4 Geometry

  • The example geometry is shown here:

BubbleEx.gif


  • GEANT4 Photon-Inelastic Model: CHIPS Gamma Nuclear has this cross section for our reaction:

G4 CrossSection.gif

  • To-do List:
  1. Use github.com to manage the simulation software.
  2. Encode the geometry in GDML, an XML based format that Geant4 reads in.
  3. Include the Bubble Chamber geometry using the Bubble Chamber STEP file (change .txt to .stp): media:BubbleChamber.txt.
  4. The beamline STEP file will be ready very soon.
  5. GEANT4 uses models that calculate wrong photo–nuclear cross sections (see above). GEANT4 does not allow for user’s cross sections. What to do?
    1. Use GEANT4 to produce the photon spectra impinging on the superheated liquid.
    2. Fold the above photon spectra with our cross sections in stand-alone codes.


Relevant Cross Sections

  • Photo-Nuclear Cross Sections:
CrossSections.gif
  1. 16O(γ,α)12C media:cs16Oga.txt (Eg (MeV), Cross Section (b))
  2. 17O(γ,α)13C media:cs17Oga.txt
  3. 18O(γ,α)14C media:cs18Oga.txt
  4. 14N(γ,p)13C media:cs14Ngp.txt


  • Neutron Elastic Cross Sections:
  1. 16O(n,n) media:cs16Onn.txt (En (MeV), Cross Section (b))
  2. 14N(n,n) media:cs14Nnn.txt
Cs16Onn.gif
Cs14Nnn.gif