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Title: ATTILA: A three-dimensional, unstructured tetrahedral mesh discrete ordinates transport code

Abstract

Many applications of radiation transport require the accurate modeling of complex three-dimensional geometries. Historically, Monte Carlo codes have been used for such applications. Existing deterministic transport codes were not applied to such problems because of the difficulties of modeling complex three-dimensional geometries with rectangular meshes. The authors have developed a three-dimensional discrete ordinates (S{sub n}) code, ATTILA, which uses linear-discontinuous finite element spatial differencing in conjunction with diffusion-synthetic acceleration (DSA) on an unstructured tetrahedral mesh. This tetrahedral mesh capability enables the authors to efficiently model complex three-dimensional geometries. One interesting and challenging application of neutron and/or gamma-ray transport is nuclear well-logging applications. Nuclear well-logging problems usually involve a complex geometry with fixed sources and one or more detectors. Detector responses must generally be accurate to within {approx}1%. The combination of complex three-dimensional geometries and high accuracy requirements makes it difficult to perform logging problems with traditional S{sub n} differencing schemes and rectangular meshes. Hence, it is not surprising that deterministic S{sub n} codes have seen limited use in nuclear well-logging applications. The geometric modeling capabilities and the advanced spatial differencing of ATTILA give it a significant advantage, relative to traditional S{sub n} codes, for performing nuclear well-logging calculations.

Authors:
; ;  [1]
  1. Los Alamos National Lab., NM (United States)
Publication Date:
OSTI Identifier:
426394
Report Number(s):
CONF-961103-
Journal ID: TANSAO; ISSN 0003-018X; TRN: 96:006307-0116
Resource Type:
Journal Article
Journal Name:
Transactions of the American Nuclear Society
Additional Journal Information:
Journal Volume: 75; Conference: Winter meeting of the American Nuclear Society (ANS) and the European Nuclear Society (ENS), Washington, DC (United States), 10-14 Nov 1996; Other Information: PBD: 1996
Country of Publication:
United States
Language:
English
Subject:
02 PETROLEUM; 66 PHYSICS; RADIATION TRANSPORT; DISCRETE ORDINATE METHOD; A CODES; MESH GENERATION; FINITE ELEMENT METHOD; RADIOACTIVITY LOGGING

Citation Formats

Wareing, T A, McGhee, J M, and Morel, J E. ATTILA: A three-dimensional, unstructured tetrahedral mesh discrete ordinates transport code. United States: N. p., 1996. Web.
Wareing, T A, McGhee, J M, & Morel, J E. ATTILA: A three-dimensional, unstructured tetrahedral mesh discrete ordinates transport code. United States.
Wareing, T A, McGhee, J M, and Morel, J E. Tue . "ATTILA: A three-dimensional, unstructured tetrahedral mesh discrete ordinates transport code". United States.
@article{osti_426394,
title = {ATTILA: A three-dimensional, unstructured tetrahedral mesh discrete ordinates transport code},
author = {Wareing, T A and McGhee, J M and Morel, J E},
abstractNote = {Many applications of radiation transport require the accurate modeling of complex three-dimensional geometries. Historically, Monte Carlo codes have been used for such applications. Existing deterministic transport codes were not applied to such problems because of the difficulties of modeling complex three-dimensional geometries with rectangular meshes. The authors have developed a three-dimensional discrete ordinates (S{sub n}) code, ATTILA, which uses linear-discontinuous finite element spatial differencing in conjunction with diffusion-synthetic acceleration (DSA) on an unstructured tetrahedral mesh. This tetrahedral mesh capability enables the authors to efficiently model complex three-dimensional geometries. One interesting and challenging application of neutron and/or gamma-ray transport is nuclear well-logging applications. Nuclear well-logging problems usually involve a complex geometry with fixed sources and one or more detectors. Detector responses must generally be accurate to within {approx}1%. The combination of complex three-dimensional geometries and high accuracy requirements makes it difficult to perform logging problems with traditional S{sub n} differencing schemes and rectangular meshes. Hence, it is not surprising that deterministic S{sub n} codes have seen limited use in nuclear well-logging applications. The geometric modeling capabilities and the advanced spatial differencing of ATTILA give it a significant advantage, relative to traditional S{sub n} codes, for performing nuclear well-logging calculations.},
doi = {},
journal = {Transactions of the American Nuclear Society},
number = ,
volume = 75,
place = {United States},
year = {1996},
month = {12}
}