Re: default cut value for thin absorber

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On Thu, 07 May 2009 16:05:22 GMT, Sang-jun Lee wrote:
> I'm trying to simulate isotropic 60 keV gamma-lay emission inside 4pi
> gold absorber. The thickness of the gold foil is 1 X 2 um ~ 60 X 2 um.
> At first, I set the default cut value to 20 um. I just modified a
> program from my colleague, so I had no idea of proper cut value.
> Meanwhile I came to think that when the gold absorber is as thin as 20
> um or thinner than that, the cut value of 20 um might not be
> appropriate. Now I changed it into 1 um. However, I still have no idea
> of proper value for my simulation. Could you please give me some hint?
> 
> Geant4 version : 4.9.1 CLHEP version : 1.9.2.1
> 
>   defaultCutValue = 0.001*mm;
>   cutForGamma     = defaultCutValue;
>   cutForElectron  = defaultCutValue;
>   cutForPositron  = defaultCutValue;
> 
 1- gamma interactions (Compton,PhotoElec) are cut independent (in standard Em)
 2- tracking of secondary e- : it depends of what you measure (energy deposit and or particle's fluence) and the granularity of the detector.

 Let me anticipate that your results will be rather stable for any cut values of the order or below 20 um.