|Message: Re: Scintillation rise time||Not Logged In (login)|
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> Is this crystal property implemented?
No, G4Scintillation only calculates an (exponential) 'time delay' and assumes an instantaneous rise time. And while the routine is set up to sample from a slow and a fast decay time simulataneously it doesn't account for a physical finite rise time. The code simply reads:
deltaTime = deltaTime - ScintillationTime * log( G4UniformRand() );
where deltaTime is first set to a random point/time along the step segment from where the scintillation photon is assumed to have originated.
> If not how may I do it?
I answer this with a question. How would you sample from a convolution of a finite rise-time with a finite decay time, e.g. a more realistic time distribution? If you know the code it takes to do that then the mechanism of introducing a rise-time in the material properties table is completely analogous to, for example, the "SLOWTIMECONSTANT". The G4MaterialPropertiesTable class is completely flexible in this. It simply associates a constant with a (any) character string. In your DetectorConstruction you assign the rise/decay time, for example:
G4MaterialPropertiesTable* myMPT = new G4MaterialPropertiesTable();
and in G4Scintillation.cc (you need to modify the actual G4 source) you add code to retrieve this constant:
G4MaterialPropertiesTable* aMaterialPropertiesTable =
G4double ScintillationRiseTime = aMaterialPropertiesTable->
And you'd then have to replace the single line:
ScintillationTime * log( G4UniformRand() );
with your more complicated sampling logic.
Let me know which approach to sampling from a more realistic time profile, with a rise and decay constant, you are taking. I am open to improvements of the G4 distribution.
Best regards, Peter
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