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Mathematical particle tracing: Diffuse scattering wall condition

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In Comsol 4.3a the diffuse scattering boundary condition is incorrect. it generates an angular distribution with respect to the surface normal of cos(theta), while the correct distribution is cos(theta)*sin(theta). In equation view you see that theta is is chosen by
theta = acos(0.5+random(xxx))
the correct expression is
theta=acos(sqrt(0.5+random(xxx)))
see J. Greenwood, Vacuum 67 (2002) 217–222
Comsol support showed me how to fix this in equation view. The original expression is incompatible with detailed balance

1 Reply Last Post May 3, 2013, 12:48 a.m. EDT
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago May 3, 2013, 12:48 a.m. EDT
Hi

thanks for reporting this to us out here ;) so long COMSOL has been informed to fix this for next release, the most important have been done

--
Having fun COMSOLing
Ivar
Hi thanks for reporting this to us out here ;) so long COMSOL has been informed to fix this for next release, the most important have been done -- Having fun COMSOLing Ivar

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