Publications

Abstract not provided.

The measurement of photon dose in pure gamma-ray and mixed (neutron/ gamma) field environments relies heavily on calibration of thermoluminescent dosimeters (TLDs) in cobalt-60 (Co-60) gamma irradiation environments. One of the principal means of reducing the gamma dose measurement uncertainty in Sandia National Laboratories' reactor environments is careful calibration of the CaF2:Mn TLDs used in the test environment. One issue that arises is that Co-60 gamma fields used for calibration universally have a low energy photon component. The scattered photons that make up the low energy photon component are a principal source of measurement error for the TLD calibration. ASTM E1249, Standard Practice for Minimizing Dosimetry Errors in Radiation Hardness Testing of Silicon Electronic Devices Using Co-60 Sources, describes a method that utilizes photon spectrum filter boxes to enclose devices under test that can reduce the measurement error during TLD calibration as well as during normal radiation testing of electronic components in the gamma field. Using a silicon sensor representative of a CMOS-7 technology, a series of calculations was performed for single-layer, two-layer, and three-layer filters to identify a filter box that improves the silicon dose-to-kerma ratio (that is, the filter reduces the low energy photon component in the Co-60 radiation field) in the sensor over the current filter box design. The results of the parameter study in this paper will be used to plan experimental studies in the Co-60 gamma fields used for calibration.

Abstract not provided.

Abstract not provided.

Abstract not provided.

Abstract not provided.

Abstract not provided.

Abstract not provided.

ITS is a powerful and user-friendly software package permitting state-of-the-art Monte Carlo solution of lineartime-independent coupled electron/photon radiation transport problems, with or without the presence of macroscopic electric and magnetic fields of arbitrary spatial dependence. Our goal has been to simultaneously maximize operational simplicity and physical accuracy. Through a set of preprocessor directives, the user selects one of the many ITS codes. The ease with which the makefile system is applied combines with an input scheme based on order-independent descriptive keywords that makes maximum use of defaults and internal error checking to provide experimentalists and theorists alike with a method for the routine but rigorous solution of sophisticated radiation transport problems. Physical rigor is provided by employing accurate cross sections, sampling distributions, and physical models for describing the production and transport of the electron/photon cascade from 1.0 GeV down to 1.0 keV. The availability of source code permits the more sophisticated user to tailor the codes to specific applications and to extend the capabilities of the codes to more complex applications. Version 6, the latest version of ITS, contains (1) improvements to the ITS 5.0 codes, and (2) conversion to Fortran 90. The general user friendliness of the software has been enhanced through memory allocation to reduce the need for users to modify and recompile the code.

Abstract not provided.

ITS is a powerful and user-friendly software package permitting state-of-the-art Monte Carlo solution of linear time-independent coupled electron/photon radiation transport problems, with or without the presence of macroscopic electric and magnetic fields of arbitrary spatial dependence. Our goal has been to simultaneously maximize operational simplicity and physical accuracy. Through a set of preprocessor directives, the user selects one of the many ITS codes. The ease with which the makefile system is applied combines with an input scheme based on order-independent descriptive keywords that makes maximum use of defaults and internal error checking to provide experimentalists and theorists alike with a method for the routine but rigorous solution of sophisticated radiation transport problems. Physical rigor is provided by employing accurate cross sections, sampling distributions, and physical models for describing the production and transport of the electron/photon cascade from 1.0 GeV down to 1.0 keV. The availability of source code permits the more sophisticated user to tailor the codes to specific applications and to extend the capabilities of the codes to more complex applications. Version 5.0, the latest version of ITS, contains (1) improvements to the ITS 3.0 continuous-energy codes, (2) multigroup codes with adjoint transport capabilities, (3) parallel implementations of all ITS codes, (4) a general purpose geometry engine for linking with CAD or other geometry formats, and (5) the Cholla facet geometry library. Moreover, the general user friendliness of the software has been enhanced through increased internal error checking and improved code portability.

Abstract not provided.

Abstract not provided.

Abstract not provided.

This document describes the modeling of the physics (and eventually features) in the Integrated TIGER Series (ITS) codes [Franke 04] which is largely pulled from various sources in the open literature (especially [Seltzer 88], [Seltzer 91], [Lorence 89], [Halbleib 92]), although those sources often describe the ETRAN Code from which the physics engine of ITS is derived, not necessarily identical. This is meant to be an evolving document, with more coverage and detail as time goes on. As such, entire sections are still incomplete. Presently, this document covers the continuous-energy ITS codes with more completeness on photon transport (though electron transport will not be completely ignored). In particular, this document does not cover the Multigroup code, MCODES (externally applied electromagnetic fields), or high-energy phenomena (photon pair-production). In this version, equations are largely left to the references though they may be pulled in over time.

This test plan describes the testing strategy for the ITS (Integrated-TIGER-Series) suite of codes. The processes and procedures for performing both verification and validation tests are described. ITS Version 5.0 was developed under the NNSA's ASC program and supports Sandia's stockpile stewardship mission.

ITS is a powerful and user-friendly software package permitting state of the art Monte Carlo solution of linear time-independent couple electron/photon radiation transport problems, with or without the presence of macroscopic electric and magnetic fields of arbitrary spatial dependence. Our goal has been to simultaneously maximize operational simplicity and physical accuracy. Through a set of preprocessor directives, the user selects one of the many ITS codes. The ease with which the makefile system is applied combines with an input scheme based on order-independent descriptive keywords that makes maximum use of defaults and internal error checking to provide experimentalists and theorists alike with a method for the routine but rigorous solution of sophisticated radiation transport problems. Physical rigor is provided by employing accurate cross sections, sampling distributions, and physical models for describing the production and transport of the electron/photon cascade from 1.0 GeV down to 1.0 keV. The availability of source code permits the more sophisticated user to tailor the codes to specific applications and to extend the capabilities of the codes to more complex applications. Version 5.0, the latest version of ITS, contains (1) improvements to the ITS 3.0 continuous-energy codes, (2)multigroup codes with adjoint transport capabilities, and (3) parallel implementations of all ITS codes. Moreover the general user friendliness of the software has been enhanced through increased internal error checking and improved code portability.

Design alternatives for the International Atomic Energy Agency`s Spent Fuel Attribute Tester (SFAT) were evaluated using radiation transport calculations. Several design changes were recommended and implemented in a new SFAT device. The new SFAT was tested on September 8 and 9, 1993, at the Industrial Power Company, Ltd. intermediate spent fuel storage facility in Olkiluoto, Finland. The new SFAT performed very well. The results of the tests are compared with predictions made during the SFAT optimization study.