RF Tracking Bug

Issue #124 resolved
Laurie Nevay created an issue

After updating to modular physics lists, we find the following crash in some examples:

examples/features/geometry/4_magnets/4_poles_facet.gmad

-------- EEEE ------- G4Exception-START -------- EEEE ------- *** G4Exception : had005 issued by : G4HadronicProcess::PostStepDoIt In /Users/nevay/physics/packages/geant4.10.02/source/processes/hadronic/management/src/G4EnergyRangeManager.cc, line 131: ===> GetHadronicInteraction: No Model found Target element Hydrogen Z= 1 A= 1 Unrecoverable error in the method ChooseHadronicInteraction of protonInelastic TrackID= 1 ParentID= 0 proton Ekin(GeV)= 3.20818e+06; direction= (-0.00371973,0.753094,-0.657902) Position(mm)= (-637.131,-0.000722836,9249.17); material vacuum PhysicalVolume <rf1_vacuum_pv> No HadronicInteraction found out

Fatal Exception core dump *** -------- EEEE -------- G4Exception-END --------- EEEE -------

This is actually due to a documented bug in the QGSP_BERT physics model for particle above 30TeV. Indeed, the particle is reported to have Ekin(GeV)= 3.20818e+06. The volume it is in is the rf vacuum volume.

Even more suspect is it's direction (-0.00371973,0.753094,-0.657902).

This would seem to indicate there is a bug in the rf field or the parameter units from the input (10MV/m in input gmad file one_of_each.gmad).

I found a report of the bug about Geant4 here:

http://hypernews.slac.stanford.edu/HyperNews/geant4/get/phys-list/723.html

Comments (3)

  1. Jochem Snuverink

    With recent updates the RFCavity tracking sometimes gets really slow (stuck?) which causes tests to time out. In particular this was seen with examples/features/geometry/4_magnets/3_poles_square.gmad

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