|Message: Distribution of Optical Photons||Not Logged In (login)|
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I'm modelling an Ortec 905-4 NaI(Tl) scintillator, initially with a 60Co source. The resultant optical photon distribution does not, however, resemble the expected Gaussian distribution.
Instead I seem to have a weighted Gaussian, which has a tail in the higher energies. My experimental setup is as follows:
EMLowEP + FTFP_BERT + Decay + RadioactiveDecay + OpticalPhysics 1mm cut value
1.1 MeV Gamma beam NaI(Tl) scintillator + Bialkali PMT
I'm using the Python bindings to configure the simulation, with a helper module to make it easier to create new simulations w/o introducing duplication mistakes. Therefore, although I am sharing the code, it is more use for inspection than actually being run.
The actual volumes in the scene are thus: * Scintillation detector, based on the Ortec 905 design, with an Al wall (.02" thick) + end cap, 3" (diameter, length) crystal, and an air gap on the sides of the crystal. Behind the crystal is the bialkali photocathode.
A ground tyvek surface is defined between the end cap (Al) and the crystal, and the air and the crystal.
The PMT has an optical surface with a nonzero efficiency,
Can anyone perhaps shed some light on why this might be happening?
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