|Message: Re: Tachyonic Particle Problem- Geant4 V 9.3- Ultra High Energy QGSP||Not Logged In (login)|
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Let me know if I should really hand this over to Vladimir? I'm still not sure because it's a problem with QGSP it seems.
Worked on it some more. I've narrowed the energy range where it occurs down to between 90 and 100 PeV. At 90 PeV, >95% of the runs DO NOT have this problem. (I ran 1000 events and it crashed on the 954th-)
At 100 PeV, it crashes much, much, much more often. I tried four different random seeds and they all gave the tachyonic error. Furthermore, the error is extremely strange- all of the runs crashed on nearly the same step! They crashed at different positions and different step/tracklengths/changes in energy. The process is always the same- hioni. I have a suspicion that the energies of the protons might cross some threshold and that's what causes the problem, but I can't see the energy with sufficient precision and I'm not sure how to get Geant4 to give that information without implementing a TrackingAction class. Here's what I mean:
Step# X(mm) Y(mm) Z(mm) KinE(MeV) dE(MeV) StepLeng TrackLeng NextVolume ProcName 259 0.000111 -3.2e-05 657 1e+11 0.00262 19.2 5.07e+04 Target hIoni 259 3.94e-05 8.64e-05 3.46e+03 1e+11 0.014 72.6 5.35e+04 Target hIoni 260 4.24e-05 3.32e-05 3.48e+03 1e+11 0.00561 12.1 5.35e+04 Target hIoni
My macro is the same as before up to the change in energy, and the inclusion of a setSeeds command.
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