| Summary: | High energy tail in energy deposit of protons in Geant4.4.1 | ||
|---|---|---|---|
| Product: | Geant4 | Reporter: | morim |
| Component: | processes/hadronic | Assignee: | Hans-Peter.Wellisch |
| Status: | RESOLVED FIXED | ||
| Severity: | major | CC: | morim |
| Priority: | P2 | ||
| Version: | 4.1 | ||
| Hardware: | PC | ||
| OS: | Linux | ||
| URL: | http://www.icrr.u-tokyo.ac.jp/~morim/Geant-sim/edep_old_new.jpg | ||
Dear Masaki Mori, thank you for letting us know. I'll try to fix it. Note also that end of the year, we plan to release a new model that is specially meant for nucleon-nuclear reactions below a few GeV, and has a very good chance to solve your problem for good. Many greetings, Hans-Peter. Hi, this took a while. I trtried this with g4 5.0. It works for me now, can you please verify? I think the problem was a bug in multiple scattering. Many greetings, Hans-Peter. Thank you very much for your effort, and now (Ver 4.5.1) the distribution seems to be as it should be. (Ver 4.5.0 showed still high-energy tails.) Masaki Mori |
We are calculating average energy deposit of protons in gas of various thickness. We updated the version from 4.3.2 to 4.4.1+patch to overcome the energy nonconservation of interaction of protons of around a few GeV reported in the followings: > http://wwwinfo.cern.ch/asdcgi/geant4/problemreport/show_bug.cgi?id=359 > http://wwwinfo.cern.ch/asdcgi/geant4/problemreport/show_bug.cgi?id=171 After the update, average energy deposit distribution dramatically changed as shown in the right-lower plot of the figure (see attached URL) and average energy deposit is not proportional to density, which is very unphysical. This may be caused by a long tail of energy deposit distribution shown in the left-lower plot of the figure mentioned above. Thus we are in trouble in estimating energy loss of protons in gas in both versions of Geant4. We are glad if you could fix this problem. Masaki Mori, Institute for Cosmic Ray Research, University of Tokyo