|Message: Re: electron stuck on volume boundary with (local) uniform magnetic field||Not Logged In (login)|
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Thanks for your help. Sadly, neither solution worked.
Try 1: I adjusted the minimum steplength in
IntgrDriver = new G4MagInt_Driver(1.0*micrometer, fStepper, fStepper->GetNumberOfVariables(), 2);
from 1 m to 1 cm to 1 mm to 1 micrometer, and the electron seems to get stuck at the same point each time.
I then tried explicitly changing the stepper used. I tried G4ExactHelixStepper (as before), G4ClassicalRK4, and G4HelixImplicitEuler. The electron gets stuck at the same place.
Try 2: I then commented out the stuff that manually sets the stepper and driver and was left with just:
fMagField = new G4UniformMagField(G4ThreeVector(fFieldValue, 0.0, 0.0)); fEquation = new G4Mag_UsualEqRhs(fMagField); fFieldMgr = new G4FieldManager(fMagField); fFieldMgr->CreateChordFinder(fMagField); logicBFieldZone->SetFieldManager(fFieldMgr, true);
and got the same results.
I can't help but notice that the momentum vector of this particular electron is nearly entirely in the +z direction:
WARNING - G4Navigator::ComputeStep() Track stuck, not moving for 10 steps in volume -expHall- at point (-8.257530138,-9.52505,18.49000716) direction: (-0.01057780492,7.290631171e-05,0.9999440508). Potential geometry or navigation problem ! Trying pushing it of 9e-10 mm ...
The Lorentz force on it wants to push it back into the BFieldZone volume, though the electron's momentum is carrying it across the boundary into a zero-field region. Could this be why this is happening?
Thanks for any more help you can give.
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