Message: Optical Surfaces and Sigma_Alpha Not Logged In (login)
 Next-in-Thread Next-in-Thread
 Next-in-Forum Next-in-Forum

Question Optical Surfaces and Sigma_Alpha 

Forum: Processes Involving Optical Photons
Date: 23 Jun, 2009
From: Wolfgang Lukas <Wolfgang Lukas>

Hello everyone,

I am simulating a scintillation detector setup with a 662 keV gamma source, a plastic scintillator, a photomultiplier tube and a coupling piece. My aim is to find suitable modifications for the setup (geometry, materials) in order to increase the number of optical photons hitting the PMT cathode.

To make sure I am doing things correctly, I'd like to ask you a few questions:

1) EM model for optical photons:

If I only have energies up to 662 keV (gamma) and mostly optical photon physics, which EM model should I use? LowEnergy, Penelope, Livermore, or StandardEM?

2) optical surfaces:

I wrap my plastic scintillator in various materials (e.g. Teflon, Aluminum foil) and/or apply diffuse paint. The scintillator surface itself is polished. Previously I used to define a physical air gap between scintillator and wrapping materials. Now I eliminated the gap and switched to the "...backpainted" and "...frontpainted" options for optical surfaces. Do I apply these correctly?

... Teflon wrap = polishedbackpainted

... Diffuse paint = groundfrontpainted

... Alu wrap = polishedbackpainted (with prob_ss = 1.0 for spike reflections at the aluminum surface - this should hopefully work just like a polished dielectric-metal surface with an air gap?)

3) sigma_alpha values:

Can you recommend any "typical values" of sigma_alpha for diffuse paint and Teflon?

Many, many thanks in advance!

Best regards, Wolfgang

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

1 Feedback: Re: Optical Surfaces and Sigma_Alpha   (Gumplinger Peter - 23 Jun, 2009)
(_ Question: Re: Optical Surfaces and Sigma_Alpha   (Wolfgang Lukas - 01 Jul, 2009)
1 Feedback: Re: Optical Surfaces and Sigma_Alpha   (Benton Pahlka - 01 Jul, 2009)
1 Feedback: Re: Optical Surfaces and Sigma_Alpha   (Gumplinger Peter - 02 Jul, 2009)
... 1 Message(s)
2 Feedback: Re: Optical Surfaces and Sigma_Alpha   (Gumplinger Peter - 02 Jul, 2009)
1 Idea: Re: Optical Surfaces and Sigma_Alpha   (Wolfgang Lukas - 22 Sep, 2009)
 Add Message Add Message
to: "Optical Surfaces and Sigma_Alpha"

 Subscribe Subscribe

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