Meeting 21 November 2017

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GEANT4/GEMC Model Status (Bogdan)

GEANT4/GEMC Model with updated calculations (Bogdan)


  • Donal updates on Jixie's work on background simulations to quantify prompt radiation damage with and without source
  • Materials, e.g. Cu-W alloy, were added in simulation
  • A bug in one of the routines was identified and is being fixed
  • Main goal: confirm radiation at pivot with new geometry/materials

  • GEANT4/GEMC model updates
  • Heat deposition
  • Testing 2D temperature codes (GEMC vs. G4/ROOT vs. analytical)
  • GEMC configuration: 44 Cu blocks 10x10x1, 100 GeV muons in 1cm diameter beam spot, water cooled with few mm diameter pipes (associated pressure drop might need to be revmagnet cooling pipes of few mm diameter
  • for analysis, take power profile, select position where power deposition highest (z=-55cm) and create 2D distribution
  • At the center find Tmax=380 degC
  • Analysis of Shielding - shower profiles
  • Longitudinal shower profile typical ~6 radiation lengths
  • Transverse less well known - for crystals Moliere radius (~ 1 radiation length)
  • Results show transverse profile peaked in first few fractions of radiation length - in one crystals ~90% of shower is captured (allows for position measurement). If integrate up to two radiation lengths, what fraction is captured?
  • Power profile - p. 18: MeV/length integrated over xy
  • This comes from 11 GeV beam of which 10 GeV go into absorber, divide by 15 bocks, ~600 MeV is the energy of the incident particles
  • Snapshot of power profile in zy: ~3 MeV/mm2 mean deposited energy per incident electron
  • Note on comparison with beam power
  • Outer Shielding - particle spectra
  • Exploring what particles leave to outside - challenging, since model is in GEMC and not G4, so have to implement many processes/particles
  • Anticipate to have particle spectra by end of year and optimize beginning of 2018

  • Collaboration Meeting - Tuesday, 23 January 2018 following the Hall C meeting
  • Check with Hall C program committee on details
  • Discussion about CPS talks
  • Rotatable target update(1) - anticipated to include general principles and techniques for spin-1 targets
  • Physics talks (2-3): 1) TCS, 2) KLong experiment and lattice calculations


  • Jixie update on background radiation simulations
  • Dustin update on target (either this meeting or next one)