| Summary: | Improve consistency of energy definitions for ions | ||
|---|---|---|---|
| Product: | Geant4 | Reporter: | Nicola Mori <mori> |
| Component: | processes/hadronic | Assignee: | Alberto.Ribon |
| Status: | RESOLVED FIXED | ||
| Severity: | minor | CC: | mori |
| Priority: | P5 | ||
| Version: | 10.1 | ||
| Hardware: | All | ||
| OS: | All | ||
You are absolutely right! The fix will be available in the Geant4 release 10.2, scheduled for December. |
Energy units for ions are often inconsistent in the code. For example, the dump of the FTF model says it's valid from 2 GeV to 100 TeV: Hadronic Processes for GenericIon Process: ionInelastic Model: Binary Light Ion Cascade: 0 eV ---> 4 GeV Model: FTFP: 2 GeV ---> 100 TeV However, I believe these figures are energy per nucleon rather than energy, so the units should be GeV/n and TeV/n. Indeed, when generating He4 projectiles with the gun generator setting the energy at 396 TeV there is no problem, while 401 TeV leads to a crash. So the energy figure in the model dump is E/n but the reported unit is E, while energy in the gun settings is total energy (which is fine, since units are GeV, TeV etc.). This leads often to confusion. Units should be consistent with the reported figures and documentation should clearly state if a certain parameter is considered as energy or as energy per nucleon (for example, the argument of G4HadronicInteraction::SetMinEnergy).