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.