Calculate of duration time of muons beam

Dear experts;
I want to calculate of duration time muons beam (time distribution) produced by electron beam interaction to High z-target.
I read

but actually, I do not understand clearly…
Is it possible to give me some hints to calculate the duration time ?
Best regards,

Dear Mohammad,

The most straightforward way to see the propagation time of a particle type is via a USRYIELD card. In the “Part” field please enter the type of particles you are interested in (e.g. “MUON+”, “MUON-” or “MUONS”, if you are interested in both charges) and in the “ie” field please insert “Time(s)”. Please do not forget to set the minimum (Min1) and the maximum (Max1) for the time interval (it can be quite large) and “Kind” field has to be set to “d2N/dx1dx2”.

Please tell us how it goes.

Best wishes,