Transcript ppt
Geant4 simulation for Balloon Flight Jan. 16, 2001 Software Workshop at SLAC Tsunefumi Mizuno In order to develop a G4 simulator for a Balloon Flight, we need to … • Validate simulator---Physics process, comparison with Beam Test (SLAC/Hiroshima) • Make a Cosmic-ray Generator (Masanobu at ISAS --- talk of Yasushi) • Construct a geometry (Hiroshima) • Study on tagged gamma-ray events (external target) , background, etc… (Hiroshima) • Others ? (please give your opinion) Validation of G4 simulator – Physics process Proton in Si dE/dx (MeV cm^2/g) Kinetic Energy (MeV) We also plan to examine •dE/dx in a thin material (Landau distribution) •Photon cross-section •Low-energy option (fluorescent X-ray) ………. •Others? Validation of G4 simulator– comparison with BeamTest (99) BeamTest(99) TBsim Geant4 Similar but slightly different (G4 shows smaller # of hit) Study on Balloon Flight— Tagged gamma-ray event at Target • Procedure: – Bomber Proton on Target – Search event where pi0 is generated at target – Check out whether decayed gamma-ray is converted at Tracker or not Expected number of tagged photons Target threshold: ~50 MeV 50 events/1M proton (~2hour) ~ 200events/8 hour Study on Balloon Flight— Background ( low statistics at the moment) •Bombard electron to Pressure Vessel •100k electron (1-2s) 1340 events meet Level 1 Trigger (most of them are rejected by ACD veto) Candidate for background event (bremsstrahlung at PV): a few events/100k electron Summary and Conclusions • We are now validating G4 simulator. • We have already included Pressure Vessel and VME Crate in G4 geometry. An implementation of Gondola is under progress • An expected number of tagged-photons is about 200/8 hour flight • Background estimation is started.