QwGeant4
target energy loss

Pre-scattering (external) target energy loss is simulated by throwing one primary particle starting at 30 cm upstream of the target and letting it propagate to the actual z vertex position in the target. A second primary particle is then thrown with the angle and transverse position of the first primary at that point. Event time starts when the first primary is thrown.

Todo:
need to double-check that position and momentum are properly transferred to second primary