Dear Admin: I have been encountering two problems when I run a particle shower initiated by a given hadron. I am getting the energy, position, and time information for a particle from steppingaction and trackingaction. My program is based on exampleN04 given in Geant4.5.2. I have been running showers initiated by e-, e+, gamma, proton, pi+, and pi-. I have done it for energies betwwen 10GeV and 100TeV. Problem #1. The time information for the hadrons gives 'inf' or 'nan' for some of the daughter particles in the shower. This does not happen at 10GeV but for 100GeV to 100TeV, this problem occurs for all the hadrons given above. It does not happen for the leptons given above. I have noticed the daughter particles for which the time information is lost, are almost at rest. Their kinetic energy is about a few percent of their mass. It seems the problem is in dumping those particle when they are about to stop. PROBELM # 2. At 100 TeV, I the pi- initiated shower gives this error after running for a few hours: Unrecoverable error for: - Particle energy[GeV] = 19652.5 - Material = Ice - Particle type = anti_lambda GetHadronicProcess: No model found for this energy range *** G4Exception: Aborting execution *** ./showans.exe: line 1: 15691 Aborted BEST REGARDS. Shahid
Hi, problem 2 is simple: None of the physics lists distrobuted can do energies above 14TeV. As for problem 1, Michel may be able to aid you. Many greetings, Hans-Peter.
Hi, a precision problem in elastic scattering off hydrogen can lead to slightly negative values for the kinetic energy, giving this effect. Fix will be released in geant4 6.0. Many greetings, Hans-Peter.
Hi Peter, thanks for the reply. About problem # 2, I was wondering if the next geant release will have physics tables extrapolated to energies higher than 14TeV for the corresponding hasdrons (like kaons and anti-baryons)? And for protons and pions, will it be extrapolated above a 100TeV? Thanks alot. Shahid
