We consider the forces acting on the muon following the d-t fusion and show that it is improper to neglect the α-μ Coulomb interaction. We further show that the muon separation from the α particle is large at the time both interact with matter. This invalidates the assumption of pointlike source for transport studies of the muon evolution. We conclude, therefore, that the comment made by Jändel is physically incorrect.

• Received 6 July 1990

DOI:https://doi.org/10.1103/PhysRevA.43.601