Date: Thu, 14 Nov 2013 14:37:16 -0800
Hello everyone,
A friend of mine at TRIUMF (cc'd above) asked me whether I could quickly
setup 70 MeV positrons on a simple cylindrically shaped NaI and look at
the total deposited energy distribution. I had other pressing projects
on my plate and had never looked at dep. energy on an event by event
basis so it took me a little while.
In the FLUKA project:
I am using NEW-DEFA for default (thresholds, etc), pho-nuclear
interactions turned on, as well as coalescence and evaporation.
I have set production and transport energy cut offs to 100 keV (KE) for
e+,e- and 10 keV for photons.
I have used LAM-BIAS
- to reduce the inelastic interaction length by 0.02.
- to set the LPB to 1 MeV for e+,e-.
That's about it. But when we look at the deposited energy distribution
(data + Geant4 + FLUKA), there are two broad bumps below the main peak
in the data that is missing from the FLUKA results but somewhat
reproduced by Geant4.
Does anyone know where this difference is coming from? Have I not
included some relevant physics in my simulation?
Thanks and best wishes,
Mina
(image/jpeg attachment: data_fluka_G4.jpg)