Problem in G4PathFinder::ReportMove()

I run Geant4(10.06) on wsl2. I simulated proton beam passing through a small phantom, the size of each pixel of the phantom was 0.15mm × 0.15mm × 0.15mm, and the following errors occurred during the simulation:

What caused this? How can I solve this problem? Looking forward to your reply!


It’s not too clear what could have caused the problem, at least not without more information.
In particular what physics list was being used - is it one of the standard Geant4 physics lists?

The length which is reported 9.99999918e-8 mm ~= 1.0e-7 mm means that I would not worry about this particular instance of the message. If the distances though started to grow such that they are much closer to comparable to the dimensions of your shape (e.g. 1.e-4-0.001 or even more if 0.001-0.01 of its size) it would certainly be a concern.

Since G4PathFinder is being used, I reason that either you have used a parallel geometry or created a scoring mesh.

Either way, I would suggest to try your application also with a more recent version of Geant4 - release 10.6 is now over four years old, and several problems in different parts of Geant4 have been fixed since then.

Best regards, John