A Deterministic-Monte Carlo Hybrid Method for Time-Dependent Neutron Transport Problems

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ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (727 download)

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Book Synopsis A Deterministic-Monte Carlo Hybrid Method for Time-Dependent Neutron Transport Problems by :

Download or read book A Deterministic-Monte Carlo Hybrid Method for Time-Dependent Neutron Transport Problems written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A new deterministic-Monte Carlo hybrid solution technique is derived for the time-dependent transport equation. This new approach is based on dividing the time domain into a number of coarse intervals and expanding the transport solution in a series of polynomials within each interval. The solutions within each interval can be represented in terms of arbitrary source terms by using precomputed response functions. In the current work, the time-dependent response function computations are performed using the Monte Carlo method, while the global time-step march is performed deterministically. This work extends previous work by coupling the time-dependent expansions to space- and angle-dependent expansions to fully characterize the 1D transport response/solution. More generally, this approach represents and incremental extension of the steady-state coarse-mesh transport method that is based on global-local decompositions of large neutron transport problems. An example of a homogeneous slab is discussed as an example of the new developments.

Hybrid Deterministic/Monte Carlo Methods for Solving the Neutron Transport Equation and K-Eigenvalue Problem

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Publisher :
ISBN 13 :
Total Pages : 207 pages
Book Rating : 4.:/5 (878 download)

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Book Synopsis Hybrid Deterministic/Monte Carlo Methods for Solving the Neutron Transport Equation and K-Eigenvalue Problem by : Jeffrey Alan Willert

Download or read book Hybrid Deterministic/Monte Carlo Methods for Solving the Neutron Transport Equation and K-Eigenvalue Problem written by Jeffrey Alan Willert and published by . This book was released on 2013 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt:

A Fully Coupled Monte Carlo/discrete Ordinates Solution to the Neutron Transport Equation. Final Report

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Publisher :
ISBN 13 :
Total Pages : 211 pages
Book Rating : 4.:/5 (893 download)

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Book Synopsis A Fully Coupled Monte Carlo/discrete Ordinates Solution to the Neutron Transport Equation. Final Report by :

Download or read book A Fully Coupled Monte Carlo/discrete Ordinates Solution to the Neutron Transport Equation. Final Report written by and published by . This book was released on 1990 with total page 211 pages. Available in PDF, EPUB and Kindle. Book excerpt: The neutron transport equation is solved by a hybrid method that iteratively couples regions where deterministic (S{sub N}) and stochastic (Monte Carlo) methods are applied. Unlike previous hybrid methods, the Monte Carlo and S{sub N} regions are fully coupled in the sense that no assumption is made about geometrical separation or decoupling. The hybrid method provides a new means of solving problems involving both optically thick and optically thin regions that neither Monte Carlo nor S{sub N} is well suited for by themselves. The fully coupled Monte Carlo/S{sub N} technique consists of defining spatial and/or energy regions of a problem in which either a Monte Carlo calculation or an S{sub N} calculation is to be performed. The Monte Carlo region may comprise the entire spatial region for selected energy groups, or may consist of a rectangular area that is either completely or partially embedded in an arbitrary S{sub N} region. The Monte Carlo and S{sub N} regions are then connected through the common angular boundary fluxes, which are determined iteratively using the response matrix technique, and volumetric sources. The hybrid method has been implemented in the S{sub N} code TWODANT by adding special-purpose Monte Carlo subroutines to calculate the response matrices and volumetric sources, and linkage subrountines to carry out the interface flux iterations. The common angular boundary fluxes are included in the S{sub N} code as interior boundary sources, leaving the logic for the solution of the transport flux unchanged, while, with minor modifications, the diffusion synthetic accelerator remains effective in accelerating S{sub N} calculations. The special-purpose Monte Carlo routines used are essentially analog, with few variance reduction techniques employed. However, the routines have been successfully vectorized, with approximately a factor of five increase in speed over the non-vectorized version.

Monte Carlo Methods and Their Application to Neutron Transport Problems

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Publisher :
ISBN 13 :
Total Pages : 72 pages
Book Rating : 4.3/5 (91 download)

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Book Synopsis Monte Carlo Methods and Their Application to Neutron Transport Problems by : Jerome Spanier

Download or read book Monte Carlo Methods and Their Application to Neutron Transport Problems written by Jerome Spanier and published by . This book was released on 1959 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Monte Carlo Principles and Neutron Transport Problems

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Publisher : Courier Corporation
ISBN 13 : 0486462935
Total Pages : 258 pages
Book Rating : 4.4/5 (864 download)

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Book Synopsis Monte Carlo Principles and Neutron Transport Problems by : Jerome Spanier

Download or read book Monte Carlo Principles and Neutron Transport Problems written by Jerome Spanier and published by Courier Corporation. This book was released on 2008-01-01 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: This two-part treatment introduces the general principles of the Monte Carlo method within a unified mathematical point of view, applying them to problems in neutron transport. It describes several efficiency-enhancing approaches, including the method of superposition and simulation of the adjoint equation based on reciprocity. The first half of the book presents an exposition of the fundamentals of Monte Carlo methods, examining discrete and continuous random walk processes and standard variance reduction techniques. The second half of the text focuses directly on the methods of superposition and reciprocity, illustrating their applications to specific neutron transport problems. Topics include the computation of thermal neutron fluxes and the superposition principle in resonance escape computations.

Extension of the Fully Coupled Monte Carlo

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Publisher :
ISBN 13 :
Total Pages : 12 pages
Book Rating : 4.:/5 (727 download)

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Book Synopsis Extension of the Fully Coupled Monte Carlo by :

Download or read book Extension of the Fully Coupled Monte Carlo written by and published by . This book was released on 1991 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The neutron transport equation is solved by a hybrid method that iteratively couples regions where deterministic (S{sub N}) and stochastic (Monte Carlo) methods are applied. Unlike previous hybrid methods, the Monte Carlo and S{sub N} regions are fully coupled in the sense that no assumption is made about geometrical separation of decoupling. The fully coupled Monte Carlo/S{sub N} technique consists of defining spatial and/or energy regions of a problem in which either a Monte Carlo calculation or an S{sub N} calculation is to be performed. The Monte Carlo and S{sub N} regions are then connected through the common angular boundary fluxes, which are determined iteratively using the response matrix technique, and group sources. The hybrid method provides a new method of solving problems involving both optically thick and optically thin regions that neither Monte Carlo nor S{sub N} is well suited for by itself. The fully coupled Monte Carlo/S{sub N} method has been implemented in the S{sub N} code TWODANT by adding special-purpose Monte Carlo subroutines to calculate the response matrices and group sources, and linkage subroutines to carry out the interface flux iterations. The common angular boundary fluxes are included in the S{sub N} code as interior boundary sources, leaving the logic for the solution of the transport flux unchanged, while, with minor modifications, the diffusion synthetic accelerator remains effective in accelerating the S{sub N} calculations. The Monte Carlo routines have been successfully vectorized, with approximately a factor of five increases in speed over the nonvectorized version. The hybrid method is capable of solving forward, inhomogeneous source problems in X-Y and R-Z geometries. This capability now includes mulitigroup problems involving upscatter and fission in non-highly multiplying systems. 8 refs., 8 figs., 1 tab.

New Splitting Iterative Methods for Solving Multidimensional Neutron Transport Equations

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Publisher : Universal-Publishers
ISBN 13 : 1599423960
Total Pages : 161 pages
Book Rating : 4.5/5 (994 download)

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Book Synopsis New Splitting Iterative Methods for Solving Multidimensional Neutron Transport Equations by : Jacques Tagoudjeu

Download or read book New Splitting Iterative Methods for Solving Multidimensional Neutron Transport Equations written by Jacques Tagoudjeu and published by Universal-Publishers. This book was released on 2011-04 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis focuses on iterative methods for the treatment of the steady state neutron transport equation in slab geometry, bounded convex domain of Rn (n = 2,3) and in 1-D spherical geometry. We introduce a generic Alternate Direction Implicit (ADI)-like iterative method based on positive definite and m-accretive splitting (PAS) for linear operator equations with operators admitting such splitting. This method converges unconditionally and its SOR acceleration yields convergence results similar to those obtained in presence of finite dimensional systems with matrices possessing the Young property A. The proposed methods are illustrated by a numerical example in which an integro-differential problem of transport theory is considered. In the particular case where the positive definite part of the linear equation operator is self-adjoint, an upper bound for the contraction factor of the iterative method, which depends solely on the spectrum of the self-adjoint part is derived. As such, this method has been successfully applied to the neutron transport equation in slab and 2-D cartesian geometry and in 1-D spherical geometry. The self-adjoint and m-accretive splitting leads to a fixed point problem where the operator is a 2 by 2 matrix of operators. An infinite dimensional adaptation of minimal residual and preconditioned minimal residual algorithms using Gauss-Seidel, symmetric Gauss-Seidel and polynomial preconditioning are then applied to solve the matrix operator equation. Theoretical analysis shows that the methods converge unconditionally and upper bounds of the rate of residual decreasing which depend solely on the spectrum of the self-adjoint part of the operator are derived. The convergence of theses solvers is illustrated numerically on a sample neutron transport problem in 2-D geometry. Various test cases, including pure scattering and optically thick domains are considered.

Modeling Feedback Effects of Transient Nuclear Systems Using Monte Carlo

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Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (14 download)

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Book Synopsis Modeling Feedback Effects of Transient Nuclear Systems Using Monte Carlo by : Miriam A. Kreher

Download or read book Modeling Feedback Effects of Transient Nuclear Systems Using Monte Carlo written by Miriam A. Kreher and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Monte Carlo neutron transport is the gold standard for accurate neutronics simulation of nuclear reactors in steady-state because each term of the neutron transport equation can be directly tallied using continuous-energy cross sections rather than needing to make approximations in energy, angle, or geometry. However, the time dependent equation includes time derivatives of flux and delayed neutron precursors which are difficult to tally. While it is straightforward to explicitly model delayed neutron precursors, and thus solve the time dependent problem in Direct Monte Carlo, this is such a costly approach that the practical length of transient calculations is limited to about 1 second. In order to solve longer problems, a high-order/low-order approach was adopted that uses the omega method to approximate the time derivatives as frequencies. These frequencies are spatially distributed and provided by a low-order Time Dependent Coarse Mesh Finite Difference diffusion solver. While this scheme has been previously applied to prescribed transients, thermal feedback is now incorporated to provide a fully self-propagating Monte Carlo transient multiphysics solver which can be applied to transients of several seconds long. Several recently developed techniques are used in the implementation of the proposed coupling approaches. Firstly, underrelaxed Monte Carlo, which is a steady-state technique that stabilizes the search for temperature distributions, is applied to find initial conditions. Secondly, tally derivatives are a Monte Carlo perturbation technique that can identify how a tally will change with respect to a small change in the system. Test problems of varying complexity are carried out in flow-initiated transients to show the versatility of these methods. Overall, this multi-level, multiphysics, transient solver provides a bridge between high fidelity Monte Carlo neutronics and the fast multi-group diffusion methods that are currently used in safety analysis.

Hybrid S[sub N]/Monte Carlo Research and Results

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Publisher :
ISBN 13 :
Total Pages : 13 pages
Book Rating : 4.:/5 (16 download)

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Book Synopsis Hybrid S[sub N]/Monte Carlo Research and Results by :

Download or read book Hybrid S[sub N]/Monte Carlo Research and Results written by and published by . This book was released on 1993 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: The neutral particle transport equation is solved by a hybrid method that iteratively couples regions where deterministic (S[sub N]) and stochastic (Monte Carlo) methods are applied. The Monte Carlo and S[sub N] regions are fully coupled in the sense that no assumption is made about geometrical separation or decoupling. The hybrid Monte Carlo/S[sub N] method provides a new means of solving problems involving both optically thick and optically thin regions that neither Monte Carlo nor S[sub N] is well suited for by themselves. The hybrid method has been successfully applied to realistic shielding problems. The vectorized Monte Carlo algorithm in the hybrid method has been ported to the massively parallel architecture of the Connection Machine. Comparisons of performance on a vector machine (Cray Y-MP) and the Connection Machine (CM-2) show that significant speedups are obtainable for vectorized Monte Carlo algorithms on massively parallel machines, even when realistic problems requiring variance reduction are considered. However, the architecture of the Connection Machine does place some limitations on the regime in which the Monte Carlo algorithm may be expected to perform well.

Monte Carlo Methods for Particle Transport

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Publisher : CRC Press
ISBN 13 : 0429584105
Total Pages : 311 pages
Book Rating : 4.4/5 (295 download)

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Book Synopsis Monte Carlo Methods for Particle Transport by : Alireza Haghighat

Download or read book Monte Carlo Methods for Particle Transport written by Alireza Haghighat and published by CRC Press. This book was released on 2020-08-09 with total page 311 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fully updated with the latest developments in the eigenvalue Monte Carlo calculations and automatic variance reduction techniques and containing an entirely new chapter on fission matrix and alternative hybrid techniques. This second edition explores the uses of the Monte Carlo method for real-world applications, explaining its concepts and limitations. Featuring illustrative examples, mathematical derivations, computer algorithms, and homework problems, it is an ideal textbook and practical guide for nuclear engineers and scientists looking into the applications of the Monte Carlo method, in addition to students in physics and engineering, and those engaged in the advancement of the Monte Carlo methods. Describes general and particle-transport-specific automated variance reduction techniques Presents Monte Carlo particle transport eigenvalue issues and methodologies to address these issues Presents detailed derivation of existing and advanced formulations and algorithms with real-world examples from the author’s research activities

A Fully Coupled Monte Carlo

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Publisher :
ISBN 13 :
Total Pages : 211 pages
Book Rating : 4.:/5 (685 download)

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Book Synopsis A Fully Coupled Monte Carlo by :

Download or read book A Fully Coupled Monte Carlo written by and published by . This book was released on 1990 with total page 211 pages. Available in PDF, EPUB and Kindle. Book excerpt: The neutron transport equation is solved by a hybrid method that iteratively couples regions where deterministic (S{sub N}) and stochastic (Monte Carlo) methods are applied. Unlike previous hybrid methods, the Monte Carlo and S{sub N} regions are fully coupled in the sense that no assumption is made about geometrical separation or decoupling. The hybrid method provides a new means of solving problems involving both optically thick and optically thin regions that neither Monte Carlo nor S{sub N} is well suited for by themselves. The fully coupled Monte Carlo/S{sub N} technique consists of defining spatial and/or energy regions of a problem in which either a Monte Carlo calculation or an S{sub N} calculation is to be performed. The Monte Carlo region may comprise the entire spatial region for selected energy groups, or may consist of a rectangular area that is either completely or partially embedded in an arbitrary S{sub N} region. The Monte Carlo and S{sub N} regions are then connected through the common angular boundary fluxes, which are determined iteratively using the response matrix technique, and volumetric sources. The hybrid method has been implemented in the S{sub N} code TWODANT by adding special-purpose Monte Carlo subroutines to calculate the response matrices and volumetric sources, and linkage subrountines to carry out the interface flux iterations. The common angular boundary fluxes are included in the S{sub N} code as interior boundary sources, leaving the logic for the solution of the transport flux unchanged, while, with minor modifications, the diffusion synthetic accelerator remains effective in accelerating S{sub N} calculations. The special-purpose Monte Carlo routines used are essentially analog, with few variance reduction techniques employed. However, the routines have been successfully vectorized, with approximately a factor of five increase in speed over the non-vectorized version.

Monte Carlo Solution of a Semi-discrete Transport Equation

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Publisher :
ISBN 13 :
Total Pages : 5 pages
Book Rating : 4.:/5 (684 download)

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Book Synopsis Monte Carlo Solution of a Semi-discrete Transport Equation by :

Download or read book Monte Carlo Solution of a Semi-discrete Transport Equation written by and published by . This book was released on 1999 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present the S{sub {infinity}} method, a hybrid neutron transport method in which Monte Carlo particles traverse discrete space. The goal of any deterministic/stochastic hybrid method is to couple selected characters from each of the methods in hopes of producing a better method. The S{sub {infinity}} method has the features of the lumped, linear-discontinuous (LLD) spatial discretization, yet it has no ray-effects because of the continuous angular variable. They derive the S{sub {infinity}} method for the solid-state, mono-energetic transport equation in one-dimensional slab geometry with isotropic scattering and an isotropic internal source. They demonstrate the viability of the S{sub {infinity}} method by comparing their results favorably to analytic and deterministic results.

Energy Research Abstracts

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Publisher :
ISBN 13 :
Total Pages : 490 pages
Book Rating : 4.0/5 ( download)

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Book Synopsis Energy Research Abstracts by :

Download or read book Energy Research Abstracts written by and published by . This book was released on 1993 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt:

A Monte Carlo Primer

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Publisher : Springer Science & Business Media
ISBN 13 : 1441984917
Total Pages : 348 pages
Book Rating : 4.4/5 (419 download)

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Book Synopsis A Monte Carlo Primer by : Stephen A. Dupree

Download or read book A Monte Carlo Primer written by Stephen A. Dupree and published by Springer Science & Business Media. This book was released on 2012-09-07 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mathematical technique of Monte Carlo, as applied to the transport of sub-atomic particles, has been described in numerous reports and books since its formal development in the 1940s. Most of these instructional efforts have been directed either at the mathematical basis of the technique or at its practical application as embodied in the several large, formal computer codes available for performing Monte Carlo transport calculations. This book attempts to fill what appears to be a gap in this Monte Carlo literature between the mathematics and the software. Thus, while the mathematical basis for Monte Carlo transport is covered in some detail, emphasis is placed on the application of the technique to the solution of practical radiation transport problems. This is done by using the PC as the basic teaching tool. This book assumes the reader has a knowledge of integral calculus, neutron transport theory, and Fortran programming. It also assumes the reader has available a PC with a Fortran compiler. Any PC of reasonable size should be adequate to reproduce the examples or solve the exercises contained herein. The authors believe it is important for the reader to execute these examples and exercises, and by doing so to become accomplished at preparing appropriate software for solving radiation transport problems using Monte Carlo. The step from the software described in this book to the use of production Monte Carlo codes should be straightforward.

Monte Carlo Particle Transport Methods

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Publisher : CRC Press
ISBN 13 : 1351083287
Total Pages : 530 pages
Book Rating : 4.3/5 (51 download)

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Book Synopsis Monte Carlo Particle Transport Methods by : I. Lux

Download or read book Monte Carlo Particle Transport Methods written by I. Lux and published by CRC Press. This book was released on 2018-05-04 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt: With this book we try to reach several more-or-less unattainable goals namely: To compromise in a single book all the most important achievements of Monte Carlo calculations for solving neutron and photon transport problems. To present a book which discusses the same topics in the three levels known from the literature and gives us useful information for both beginners and experienced readers. It lists both well-established old techniques and also newest findings.

Novel Hybrid Monte Carlo/Deterministic Technique for Shutdown Dose Rate Analyses of Fusion Energy Systems

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Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (16 download)

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Book Synopsis Novel Hybrid Monte Carlo/Deterministic Technique for Shutdown Dose Rate Analyses of Fusion Energy Systems by :

Download or read book Novel Hybrid Monte Carlo/Deterministic Technique for Shutdown Dose Rate Analyses of Fusion Energy Systems written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The rigorous 2-step (R2S) method uses three-dimensional Monte Carlo transport simulations to calculate the shutdown dose rate (SDDR) in fusion reactors. Accurate full-scale R2S calculations are impractical in fusion reactors because they require calculating space- and energy-dependent neutron fluxes everywhere inside the reactor. The use of global Monte Carlo variance reduction techniques was suggested for accelerating the neutron transport calculation of the R2S method. The prohibitive computational costs of these approaches, which increase with the problem size and amount of shielding materials, inhibit their use in the accurate full-scale neutronics analyses of fusion reactors. This paper describes a novel hybrid Monte Carlo/deterministic technique that uses the Consistent Adjoint Driven Importance Sampling (CADIS) methodology but focuses on multi-step shielding calculations. The Multi-Step CADIS (MS-CADIS) method speeds up the Monte Carlo neutron calculation of the R2S method using an importance function that represents the importance of the neutrons to the final SDDR. Using a simplified example, preliminarily results showed that the use of MS-CADIS enhanced the efficiency of the neutron Monte Carlo simulation of an SDDR calculation by a factor of 550 compared to standard global variance reduction techniques, and that the increase over analog Monte Carlo is higher than 10,000.

Handbook of Nuclear Engineering

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Publisher : Springer Science & Business Media
ISBN 13 : 0387981306
Total Pages : 3701 pages
Book Rating : 4.3/5 (879 download)

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Book Synopsis Handbook of Nuclear Engineering by : Dan Gabriel Cacuci

Download or read book Handbook of Nuclear Engineering written by Dan Gabriel Cacuci and published by Springer Science & Business Media. This book was released on 2010-09-14 with total page 3701 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is an authoritative compilation of information regarding methods and data used in all phases of nuclear engineering. Addressing nuclear engineers and scientists at all levels, this book provides a condensed reference on nuclear engineering since 1958.