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Hi, I'd just like to follow up with this! I'll rephrase my question:
What is the simplest way to model a perfectly diffuse reflector? It seems there are a few pathways to achieve this. For example, assuming we're using the UNIFIED model, we can set:
SetType: Dielectric_Metal, SetFinish: Ground, SigAlpha: 0 radians
SetType: Dielectric_Dielectric, SetFinish: GroundFrontPainted
Should these two cases produce the same optical photon reflection profile? I imagine they would differ slightly if the surface roughness of case 1 were increased.
CharlesOn Mon, 25 Sep 2017 17:26:27 GMT, Charles Sosa wrote:
> Hi, I'm simulating a cylindrical scintillator wrapped by a perfectly > diffuse reflector with no air gap. One face of the scintillator is set > as a detection surface. My questions involve the reflector. > > 1. As I understand it, a perfectly diffuse reflector with no air gap > between the scintillator and the reflector can be modeled by selecting > the SetModel to be UNIFIED, the SetType to be dielectric_dielectric, and > the SetFinish to be groundfrontpainted. Is this understanding correct? > I'm referencing the attachment. > > 2. If the first statement is correct, would it therefore be redundant to > add the following three reflector properties: > specularspikeconstant(SS)=0, specularlobeconstant(SL)=0, and > backscatterconstant(BS)=0, where lambertian (L) reflection is implicit > (SS+SL+BS+L=1) to such a reflector configuration (namely: UNIFIED, > dielectric_dielectric, groundfrontpainted)? > > 3. Out of curiosity, if I selected polishedfrontpainted instead of > groundfrontpainted (with UNIFIED and dielectric_dielectric), in addition > to setting SS=SL=BS=0 (L=1), would the reflector converge to Lambertian? > I'm wondering if the reflector constants would override the > specularspike reflection mode designated by polishedfrontpainted. > > Thanks! > > Charles > > Attachment: > http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2017/09/25/09.11-13073-unifiedModel.png >
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