Message: Trying to understand how pion ioniozation losses are related to the range cut for electron Not Logged In (login)
 Next-in-Thread Next-in-Thread
 Next-in-Forum Next-in-Forum

Question Trying to understand how pion ioniozation losses are related to the range cut for electron 

Forum: Physics List
Date: 19 Sep, 2017
From: Aleksey Sher <Aleksey Sher>

Hello, I am using geant4.9.3.p02, and came upon a peculiar problem.

I run a very simple simulation of a 70 MeV/c momentum pion, going into a plastic scintillator (3cm think) which stops it completely.

I noticed that the stopping distribution changes (shifts) if I reduced my nominal rangecut for electrons from 0.1mm to 0.01 mm.

    SetCutValue(fCutForElectron, "e-");  

Effect is not large, but is definitely sizable, and consistent.

by verbilizing the event I noticed that during the pion tracking in the scintillator, hIoni process is invoked, which produces secondaries (delta rays). And in case of a smaller range cut for electrons, number of secondaries produced by pion is about twice as large.

I can hypothesize that this is due to a smaller rangecut for electron which somehow overridden the production threshold for delta rays in the ionization process.
 I am ok with that, but why do the stopping distribution changes, that is what puzzles me.

I also observed a change in the visible energy (being smaller with the smaller range cut for electrons). This I think is due to birk's coefficient doing it's job in the case of electrons, being tracked longer.

My question is how is electron parameter (in this case rangecut) can be connected to the pion loosing it's energy and stopping in the medium.

Inline Depth:
 1 1
 All All
Outline Depth:
 1 1
 2 2
 All All
Add message: (add)

1 Idea: Re: Trying to understand how pion ioniozation losses are related to the range cut for electron   (Vladimir Ivanchenko - 28 Sep, 2017)
 Add Message Add Message
to: "Trying to understand how pion ioniozation losses are related to the range cut for electron"

 Subscribe Subscribe

This site runs SLAC HyperNews version 1.11-slac-98, derived from the original HyperNews


[ Geant 4 Home | Geant 4 HyperNews | Search | Request New Forum | Feedback ]