Message: Time of photons in scintillation process Not Logged In (login)
 Next-in-Thread Next-in-Thread
 Next-in-Forum Next-in-Forum

None Time of photons in scintillation process 

Forum: Processes Involving Optical Photons
Date: 18 Dec, 2015
From: Paola Ferrario <Paola Ferrario>

Hi, there is something I don't understand about the way scintillation is simulated in geant4. I'm setting just one decay time constant, the fast one, for the moment, with the following optical property to my material (LXe):

 LXe_mpt->AddConstProperty("FASTTIMECONSTANT", 2.2*ns);

If I plot the time of each optical photon produced in the scintillation, I find the histogram that you can find here:

https://www.dropbox.com/s/zjrkzcp5w5kd7vt/ScintillationTime2.2ns.root?dl=0

, where x axis is time in picoseconds. I'm a bit puzzled by the first two bins of this histogram, which show a higher content than that I would expect from the following distribution:

N/tau*exp(-t/tau),

where tau = 2.2 ns and N the total number of photons emitted (in my case, around 30 000). I attach a plot of this function between 0 and 100 ps (exp.pdf).

Is this the function geant4 samples to simulate the decay time?

   Attachment:
      http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2015/12/18/05.58-26732-exp.pdf

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

1 None: Re: Time of photons in scintillation process   (Paola Ferrario - 18 Dec, 2015)
(_ Feedback: Re: Time of photons in scintillation process   (Gumplinger Peter - 07 Jan, 2016)
 Add Message Add Message
to: "Time of photons in scintillation process"

 Subscribe Subscribe

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