I correct process name proptonInelastic -> protonInelastic and I get result.
However, still some problem is remain. I measure how many time the process occur two method. One is using my code(already fixed) and another is count manually. but in detector, result from two method is different. result from code is have more event than second method.
It bring next step starting point not interaction point.
I change my code
G4double positionZ = step->GetPreStepPoint()->GetPosition().z();
to
G4double pz = aTrack->GetVertexPosition().z();