scholarly journals The MAVRIC-Shift Sequence in SCALE for Radiation Transport and Shielding Calculations with Automated Variance Reduction and Parallel Computing

2019 ◽  
Author(s):  
Gregory Davidson ◽  
Kaushik Banerjee ◽  
Cihangir Celik ◽  
Thomas Evans ◽  
Bradley Rearden ◽  
...  
Keyword(s):  
Parallel Computing ◽  
Variance Reduction ◽  
Radiation Transport ◽  
Shift Sequence

scholarly journals Correction to: A source biasing and variance reduction technique for Monte Carlo radiation transport modeling of emission tomography problems

2020 ◽  
Vol 324 (1) ◽  
pp. 445-446
Author(s):  
Seth Kilby ◽  
Zhongmin Jin ◽  
Ashish Avachat ◽  
Bryant Kanies ◽  
Nicolas Woolstenhulme ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Variance Reduction ◽  
Radiation Transport ◽  
Reduction Technique ◽  
Transport Modeling ◽  
Emission Tomography ◽  
Variance Reduction Technique

A Multi-Mechanics Approach to Computational Heat Transfer

2002 ◽  
Author(s):  
C. D. Moen ◽  
G. H. Evans ◽  
S. P. Domino ◽  
S. P. Burns
Keyword(s):  
Heat Transfer ◽  
Parallel Computing ◽  
Turbulent Combustion ◽  
Message Passing ◽  
Radiation Transport ◽  
Finite Volume Scheme ◽  
Participating Media ◽  
Parallel Performance ◽  
Accident Scenarios ◽  
Transfer Problems

We present a turbulent combustion code for modeling heat transfer in fires that arise in accident scenarios. The code is a component of a multi-mechanics framework and is based on a domain-decomposition, message-passing approach to parallel computing. The turbulent combustion code is based on a vertex-centered, finite-volume scheme for 3D unstructured meshes. The multi-mechanics nature of the frameworks allows us to couple to a conduction heat transfer code for conjugate heat transfer problems or a participating media radiation code for radiation transport in soot-laden flows. We describe our numerical methods, our approach to parallel computing, and the multi-mechanics frameworks. We demonstrate parallel performance using some example verification problems.

scholarly journals Variance-Reduction Methods for Monte Carlo Simulation of Radiation Transport

2021 ◽  
Vol 9 ◽  
Author(s):  
Salvador García-Pareja ◽  
Antonio M. Lallena ◽  
Francesc Salvat
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Variance Reduction ◽  
Radiation Transport ◽  
Scattering Method ◽  
Variance Reduction Techniques ◽  
Simulation Efficiency ◽  
Reduction Techniques ◽  
Exponential Transform ◽  
Reduction Methods

After a brief description of the essentials of Monte Carlo simulation methods and the definition of simulation efficiency, the rationale for variance-reduction techniques is presented. Popular variance-reduction techniques applicable to Monte Carlo simulations of radiation transport are described and motivated. The focus is on those techniques that can be used with any transport code, irrespective of the strategies used to track charged particles; they operate by manipulating either the number and weights of the transported particles or the mean free paths of the various interaction mechanisms. The considered techniques are 1) splitting and Russian roulette, with the ant colony method as builder of importance maps, 2) exponential transform and interaction-forcing biasing, 3) Woodcock or delta-scattering method, 4) interaction forcing, and 5) proper use of symmetries and combinations of different techniques. Illustrative results from analog simulations (without recourse to variance-reduction) and from variance-reduced simulations of various transport problems are presented.

Monte Carlo Simulation of Characteristic Secondary Fluorescence in Electron Probe Microanalysis of Homogeneous Samples Using the Splitting Technique

2015 ◽  
Vol 21 (3) ◽  
pp. 753-758 ◽  
Author(s):  
Mauricio Petaccia ◽  
Silvina Segui ◽  
Gustavo Castellano
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Variance Reduction ◽  
Fluorescence Enhancement ◽  
Radiation Transport ◽  
X Rays ◽  
X Ray ◽  
Secondary Fluorescence

AbstractElectron probe microanalysis (EPMA) is based on the comparison of characteristic intensities induced by monoenergetic electrons. When the electron beam ionizes inner atomic shells and these ionizations cause the emission of characteristic X-rays, secondary fluorescence can occur, originating from ionizations induced by X-ray photons produced by the primary electron interactions. As detectors are unable to distinguish the origin of these characteristic X-rays, Monte Carlo simulation of radiation transport becomes a determinant tool in the study of this fluorescence enhancement. In this work, characteristic secondary fluorescence enhancement in EPMA has been studied by using the splitting routines offered by PENELOPE 2008 as a variance reduction alternative. This approach is controlled by a single parameter NSPLIT, which represents the desired number of X-ray photon replicas. The dependence of the uncertainties associated with secondary intensities on NSPLIT was studied as a function of the accelerating voltage and the sample composition in a simple binary alloy in which this effect becomes relevant. The achieved efficiencies for the simulated secondary intensities bear a remarkable improvement when increasing the NSPLIT parameter; although in most cases an NSPLIT value of 100 is sufficient, some less likely enhancements may require stronger splitting in order to increase the efficiency associated with the simulation of secondary intensities.

Analysis of the LIFT Variance-Reduction Method Applied to Monte Carlo Radiation Transport Simulations of a Realistic Nonproliferation Test Problem

2016 ◽  
Vol 193 (3) ◽  
pp. 391-403
Author(s):  
Elanchezhian Somasundaram ◽  
Todd S. Palmer
Keyword(s):  
Monte Carlo ◽  
Test Problem ◽  
Variance Reduction ◽  
Reduction Method ◽  
Radiation Transport

Application of ADVANTG variance reduction parameters with MCNP6 at ESS

2020 ◽  
Vol 22 (2-3) ◽  
pp. 199-208
Author(s):  
Thomas M. Miller ◽  
Douglas D. DiJulio ◽  
Valentina Santoro
Keyword(s):  
Monte Carlo ◽  
Activation Analysis ◽  
Variance Reduction ◽  
Radiation Transport ◽  
Neutron Sources ◽  
Reduction Methods

Monte Carlo radiation transport codes have become the primary tool for shielding and activation analysis at high-powered spallation neutron sources. However, use of these codes to model facilities that have large amounts of shielding requires the use of variance reduction methods. This paper presents examples that apply ADVANTG generated variance reduction parameters to analyses performed at ESS using MCNP6. This requires some limitations in ADVANTG to be overcome and little-known features to be used. The focus of this paper is to describe how these limitations were overcome so other analyst at spallation sources can benefit from these methods as well.

Development and assessment of a parallel computing implementation of the Coarse Mesh Radiation Transport (COMET) method

2018 ◽  
Vol 114 ◽  
pp. 288-300
Author(s):  
Kyle Remley ◽  
Farzad Rahnema
Keyword(s):  
Parallel Computing ◽  
Radiation Transport ◽  
Coarse Mesh
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