An angular biasing method using arbitrary convex polyhedra for Monte Carlo radiation transport calculations
Abstract
This paper presents a new method for performing angular biasing in Monte Carlo radiation transport codes using arbitrary convex polyhedra to define regions of interest toward which to project particles (DXTRAN regions). The method is derived and is implemented using axisaligned right parallelepipeds (AARPPs) and arbitrary convex polyhedra. Attention is also paid to possible numerical complications and areas for future refinement. A series of test problems are executed with void, purely absorbing, purely scattering, and 50% absorbing/50% scattering materials. For all test problems tally results using AARPP and polyhedral DXTRAN regions agree with analog and/or spherical DXTRAN results within statistical uncertainties. In cases with significant scattering the figure of merit (FOM) using AARPP or polyhedral DXTRAN regions is lower than with spherical regions despite the ability to closely fit the tally region. This is because spherical DXTRAN processing is computationally less expensive than AARPP or polyhedral DXTRAN processing. Thus, it is recommended that the speed of spherical regions be considered versus the ability to closely fit the tally region with an AARPP or arbitrary polyhedral region. It is also recommended that short calculations be made prior to final calculations to compare the FOM for the various DXTRAN geometries because ofmore »
 Authors:

 Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Nuclear Engineering and Radiological Sciences; Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
 Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
 Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Nuclear Engineering and Radiological Sciences
 Publication Date:
 Research Org.:
 Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Univ. of Michigan, Ann Arbor, MI (United States)
 Sponsoring Org.:
 USDOE National Nuclear Security Administration (NNSA), Office of Nonproliferation and Verification Research and Development (NA22); USDOE
 OSTI Identifier:
 1438017
 Alternate Identifier(s):
 OSTI ID: 1524371
 Report Number(s):
 LAUR1729230
Journal ID: ISSN 03064549; PII: S0306454917304991
 Grant/Contract Number:
 NA0002576; 89233218CNA000001
 Resource Type:
 Accepted Manuscript
 Journal Name:
 Annals of Nuclear Energy (Oxford)
 Additional Journal Information:
 Journal Name: Annals of Nuclear Energy (Oxford); Journal Volume: 114; Journal Issue: C; Journal ID: ISSN 03064549
 Publisher:
 Elsevier
 Country of Publication:
 United States
 Language:
 English
 Subject:
 97 MATHEMATICS AND COMPUTING; 73 NUCLEAR PHYSICS AND RADIATION PHYSICS; MCNP6; DXTRAN; Angular biasing; Convex hull; MCNP6, DXTRAN, Angular Biasing, Convex Hull
Citation Formats
Kulesza, Joel A., Solomon, Clell J., and Kiedrowski, Brian C. An angular biasing method using arbitrary convex polyhedra for Monte Carlo radiation transport calculations. United States: N. p., 2018.
Web. doi:10.1016/j.anucene.2017.12.045.
Kulesza, Joel A., Solomon, Clell J., & Kiedrowski, Brian C. An angular biasing method using arbitrary convex polyhedra for Monte Carlo radiation transport calculations. United States. doi:10.1016/j.anucene.2017.12.045.
Kulesza, Joel A., Solomon, Clell J., and Kiedrowski, Brian C. Tue .
"An angular biasing method using arbitrary convex polyhedra for Monte Carlo radiation transport calculations". United States. doi:10.1016/j.anucene.2017.12.045. https://www.osti.gov/servlets/purl/1438017.
@article{osti_1438017,
title = {An angular biasing method using arbitrary convex polyhedra for Monte Carlo radiation transport calculations},
author = {Kulesza, Joel A. and Solomon, Clell J. and Kiedrowski, Brian C.},
abstractNote = {This paper presents a new method for performing angular biasing in Monte Carlo radiation transport codes using arbitrary convex polyhedra to define regions of interest toward which to project particles (DXTRAN regions). The method is derived and is implemented using axisaligned right parallelepipeds (AARPPs) and arbitrary convex polyhedra. Attention is also paid to possible numerical complications and areas for future refinement. A series of test problems are executed with void, purely absorbing, purely scattering, and 50% absorbing/50% scattering materials. For all test problems tally results using AARPP and polyhedral DXTRAN regions agree with analog and/or spherical DXTRAN results within statistical uncertainties. In cases with significant scattering the figure of merit (FOM) using AARPP or polyhedral DXTRAN regions is lower than with spherical regions despite the ability to closely fit the tally region. This is because spherical DXTRAN processing is computationally less expensive than AARPP or polyhedral DXTRAN processing. Thus, it is recommended that the speed of spherical regions be considered versus the ability to closely fit the tally region with an AARPP or arbitrary polyhedral region. It is also recommended that short calculations be made prior to final calculations to compare the FOM for the various DXTRAN geometries because of the influence of the scattering behavior.},
doi = {10.1016/j.anucene.2017.12.045},
journal = {Annals of Nuclear Energy (Oxford)},
number = C,
volume = 114,
place = {United States},
year = {2018},
month = {1}
}
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