I find the same issue in my simulations with Geant4.10.7 (and patch 1), where this did not exist in 4.10.4. It seems to only affect pions and I found that almost all aborted events occurred at/crossed material boundaries/volumes, calculating a negative step size of km in magnitude. There was some small percentage that were not aborted at the boundary but they were aborted in the following step. I did not identify an individual process that caused this though.
From your full trace I think the same thing is happening, it occurs right after going between support_telescope5_phys_0 and World volumes and has the same symptoms, could you confirm?
I do not have a solution, but perhaps this confirmation may help towards diagnosing the problem.
I see pions (pos/neg) as well as kaons and protons causing this issue, so it seems to definitely be a hadronic issue. I can confirm your other observation that this always seems to happen at volume boundaries.
Interesting that it occurs with protons for you, I only see this with pions (charged and uncharged) that have been produced from an initial proton beam, but no protons are aborted from what I can see.
I played a bit around with different physics lists:
FTFP_BER_EMV - no aborted events
FTFP_BER_EMX - no aborted events
FTFP_BER_EMY - problem with aborted events
FTFP_BER_EMZ - problem with aborted events
FTFP_BER_LIV - no aborted events
QGSP_BER_EMV - no aborted events
QGSP_BER_EMX - no aborted events
QGSP_BER_EMY - problem with aborted events
QGSP_BER_EMZ - problem with aborted events
QGSP_BER_LIV - no aborted events
In conclusion, it seems to only appear with the electromagnetic extensions _EMY and _EMZ. Interestingly, _LIV does not show the problem despite being an extention of _EMY afaik.
thank you for pointing to a possible problem. Unfortunately, not obvious where and why this happens. Can you, please, formulate it in the Bugzilla bug report system (https://bugzilla-geant4.kek.jp/)?
any news on that: I could not see any update from the Bugzilla report. I have a very similar problem, when simulating some ions in 10.7.
E.g. Pb208:
G4ParticleChange::CheckIt : the proper time goes back !! Difference: 0.0002[ns]
Pb208 E=0.17 pos=-0.00085, -0.0054, 0.0022 global time=2.3e+13 local time=0 proper time=0
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G4ParticleChange Information
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# of 2ndaries : 0
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Energy Deposit (MeV): 0
Non-ionizing Energy Deposit (MeV): 0
Track Status : Alive
True Path Length (mm) : -7.96e-05
Stepping Control : 0
First Step In the voulme :
Mass (GeV) : 0
Charge (eplus) : 0
MagneticMoment : 0
: = 0*[e hbar]/[2 m]
Position - x (mm) : -0.851
Position - y (mm) : -5.44
Position - z (mm) : 2.25
Time (ns) : -0.000201
Proper Time (ns) : -0.000201
Momentum Direct - x : 0.68
Momentum Direct - y : 0.73
Momentum Direct - z : 0.0609
Kinetic Energy (MeV): 0.169
Velocity (/c): 0.00132
Polarization - x : 0
Polarization - y : 0
Polarization - z : 0
Touchable (pointer) : 0x381caa0
G4VParticleChange::CheckIt : the true step length is negative !! Difference: 8e-05[MeV]
Pb208 E=0.17 pos=-0.00085, -0.0054, 0.0022
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