Track is stuck in uniform magnetic field

hi all!

After adding box with homogeneous perpendicular magnetic field inside I have the following output:

    -------- WWWW ------- G4Exception-START -------- WWWW -------
*** G4Exception : GeomNav1002
      issued by : G4Navigator::ComputeStep()
Track stuck or not moving.
          Track stuck, not moving for 10 steps
          in volume -logicMagnet- at point (85.47176328751029,175,2603.276064753403) (local point (85.47176328751029,175,485.2760647534033))
          direction: (-0.2425696513096997,0.002679084884248989,-0.9701302937068162) (local direction: (-0.2425696513096997,0.002679084884248989,-0.9701302937068162)).
          Potential geometry or navigation problem !
          Trying pushing it of 1e-07 mm ...Potential overlap in geometry!

*** This is just a warning message. ***
-------- WWWW -------- G4Exception-END --------- WWWW -------

I have no volumes overlaps…
Does anyone have idea where the problem can be? And how to fix it?

EDIT: I had 2 runs without this warning. Probably it happens rarely


Hi FoxWise:
I’m facing the same problem, and have you solved that?

Hi, @SaulTang

No, sorry…

It was a long time ago and the geometry was in a draft phase at that moment, so I played with it a lot.
In the end I think I got rid of it, but have no clue how…

The only bug I remember from that time, that I used the wrong constructor for magnetic field:
fMagneticField = new G4UniformMagField(0.095*tesla, 0, 0);
when I needed this one:
fMagneticField = new G4UniformMagField(G4ThreeVector(0.095*tesla, 0, 0));

First one defines it in spherical coordinate system, 2nd assume x,y,z input.
Maybe this weird magnetic field caused it?

Don’t have any other hints for you…