Bewertung und Implementierung von optimierten Raytracing-Algorithmen in BREPbasierten Monte Carlo Transport Codes
Bewertung und Implementierung von optimierten Raytracing-Algorithmen in BREPbasierten Monte Carlo Transport Codes
The Monte Carlo Transport Code EIRENE has been optimized by implementation of raytracing algorithms adopted from computer graphics applications. In particular the original boundary representation (BREP) procedure used in EIRENE for specifying complex 3D configurations by a number of first or second...
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Personal Name(s): | Schmidt, O. (Corresponding author) |
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Reiter, D. / Börner, P. | |
Contributing Institute: |
Plasmaphysik; IEK-4 |
Imprint: |
Jülich
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag
2013
|
Physical Description: |
IV, 56, VII-XXIV p. |
Document Type: |
Report Book |
Research Program: |
ohne Topic |
Series Title: |
Berichte des Forschungszentrums Jülich
4360 |
Link: |
OpenAccess OpenAccess |
Publikationsportal JuSER |
The Monte Carlo Transport Code EIRENE has been optimized by implementation of raytracing algorithms adopted from computer graphics applications. In particular the original boundary representation (BREP) procedure used in EIRENE for specifying complex 3D configurations by a number of first or second order algebraic surface segments has been speeded up considerably for model cases in which the number of surface segments in the model is large. This is achieved by an Octree based optimization procedure, replacing the original linear search algorithm of EIRENE to identify the point of intersection of a straight line (the flight path of a Monte Carlo trajectory) with any of the surface segments used to specify the geometrical model of the particle transport simulation. Here weutilize the mathematical analogy between ray-tracing problems and Monte Carlo particle tracing. After successful implementation of the optimized procedure in EIRENE module TIMEA.F and a number of code profiling studies this module turned out not to be the most time consuming part any more; the evaluation of the statistical error estimates (standard deviations) of surface averaged quantities (e.g. fluxes, energy fluxes, sputter yields) had instead moved up in the list of most CPU critical components. Also this part of the code was then optimized by implementing the same indirect addressing concept for surface tally statistics as was already implemented in EIRENE back in the eighties of the last century for all volume averaged quantities, leading to a further significant speed-up of EIRENE for model cases of complex (many thousand surface segments) 3D configurations. |