ELECTROMAGNETIC WORKING GROUP plan of activity for 2012

(1) - June 2012

(2) - December 2012

[LE] - in collaboration with the Low-energy EM working group

1) LHC experiments support

  • EM shower shape - ATLAS and CMS (1/2)
  • Energy deposition in tracking detectors - ALICE (1/2)
  • Multiple and single scattering - LHCb (1/2)

2) R&D study on multi-threading and vectorized simulation for EM physics (1/2)

3) Validation and verification of EM physics:

  • perform regular execution and regresion analysis using existing testing suites (1/2)
  • continue detailed comparison of Standard, Livermore and Penelope models [LE] (1/2)
  • adding ILC (including CALICE) calorimeter tests (2)
  • adding extra benchmark for bremsstrahlung (2)
  • improved CPU benchmarking (1/2)

4) EM infrastructure update:

  • improved interface to angular generator (1)
  • reduce initialisation time and memory for muons (1)
  • move initialisation of tables for multiple scattering from process to model, introduce base material approach for multiple scattering (1)

5) Further update of ionization processes:

  • review and improvements for fluctuation models (1/2)

6) Further development of the processes of multiple and single scattering:

  • further development of WentzelVI model (1)
  • further development of Goudsmit-Saunderson model (1)
  • review and improved interaction between Transportation and Multiple scattering including lateral displacement and step limitation (1/2)
  • hadron multiple scattering coherent with hadron diffuse model (2)

7) Bremsstrahlung and gamma-conversion models:

  • introduce parameterisation of Seltzer-Berger cross sections instead of data table (1/2)
  • improved parameterisation for positron cross section (2)
  • improved angular generator (1/2)
  • updated gamma-conversion model at low-energies [LE](2)

8) Improvements in high energy processes

  • migration of mu+mu- production to model design(2)
  • improved angular generator for synchrotron radiation (1)
  • review of the model of e+e- pair production (1)

9) Optical photon physics

  • Extension to the unified surface model to have both specular and diffuse components for the transmitted photons (1)
  • Modeling of optical transport in a volume that has different optical treatments on different sides (2)

10) Shopping list for work items for which no manpower assigned


  • provide range computations in G4EmCalculator
  • improved ion stopping in G4EmCalculator Validation/examples:
  • adding test on fluctuation of energy loss at moderate energies
  • improve and extend validation of shower shape
  • adding extra automatic tests on hadron scattering
  • new validation of EM showers in light media (air, ice)
  • new validation for muon cooling simulations
  • improve validation of energy loss fluctuations
  • providing example for ultra-relativistic gamma-conversion model New/improved models:
  • improved X-rays fluorescence sampling in photo-electric model
  • improved Compton scattering model with Doppler broading New optical features:
  • Implementation of a more flexible micro facet sampling method for optical surfaces
  • Extend some of the boundary process implementation to X-rays