Problem 415 - High energy tail in energy deposit of protons in Geant4.4.1
Summary: High energy tail in energy deposit of protons in Geant4.4.1
Status: RESOLVED FIXED
Alias: None
Product: Geant4
Classification: Unclassified
Component: processes/hadronic (show other problems)
Version: 4.1
Hardware: PC Linux
: P2 major
Assignee: Hans-Peter.Wellisch
URL: http://www.icrr.u-tokyo.ac.jp/~morim/...
Depends on:
Blocks:
 
Reported: 2002-10-02 23:29 CEST by morim
Modified: 2003-06-04 03:15 CEST (History)
1 user (show)

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Description morim 2002-10-02 23:29:25 CEST
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
Comment 1 Hans-Peter.Wellisch 2002-10-24 08:18:59 CEST
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.
Comment 2 Hans-Peter.Wellisch 2003-04-04 05:34:59 CEST
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.
Comment 3 morim 2003-06-04 03:15:59 CEST
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