1. NAME AND TITLE OF DATA LIBRARY
LA100: Evaluated Nuclear Data Library for Transport Calculations Involving Incident Neutrons and Protons of Energy Up to 100 MeV.
2. NAME AND TITLE OF DATA RETRIEVAL PROGRAMS
None provided. PSR-333/CHENDF6.8 may be used to access these data.
3. CONTRIBUTOR
Los Alamos National Laboratory, Los Alamos, New Mexico.
4. HISTORICAL BACKGROUND AND INFORMATION
A program has been initiated at Los Alamos National Laboratory to develop and implement proton, neutron, and photon transport libraries for incident energies up to 100 MeV. The motivation for this effort is principally the need to incorporate better nuclear physics data in applied calculations that have appreciable sensitivity to proton, neutron, and photon energies below 100 MeV. A common technique in such calculations is to utilize intranuclear-cascade/evaporation models to generate the required nuclear data. Because the physical assumptions embodied in such models are most applicable above a few hundred MeV, the use of these models below (approx.) 100 MeV is questionable. To circumvent this problem, we have extended to higher energy the range of validity of nuclear models that have been developed and tested for several tens of MeV and are constructing evaluated data libraries for proton and neutron energies to 100 MeV using these models and experimental data. The major steps involved in this effort are: (1) extension and validation of low-energy nuclear physics theoretical models for applicability up to 100 MeV; (2) development of evaluated (ENDF/B) data formats appropriate for higher energies; (3) calculation and evaluation of nuclear data in ENDF/B-VI format for appropriate materials up to 100 MeV; (4) development of processing code capabilities to handle the higher energy data; and (5) development of the appropriate interfaces and code patches for the use of the data in transport codes such as MCNP. The present transport libraries in LA100 include for proton- and neutron-induced reactions on 1H, 9Be, 12C, 16O, 27Al, 28Si, Fe, W, and 238U.
5. APPLICATION OF THE DATA
This data base was developed for use in Monte Carlo or discrete ordinate transport codes, for example, the general Monte Carlo code MCNP. Various modules of the NJOY processing code system have been enhanced to permit processing of the ENDF/B-VI formatted evaluations into both continuous-energy and multi-group format. The transport data files for all 18 projectile-plus-target systems have been processed through NJOY, and coupled multi-particle, multi-group transport libraries for MCNP now exist. In addition, pointwise MCNP libraries to 100 MeV for incident neutrons have been prepared for the nine targets. The production version of the MCNP code is being modified to handle the new pointwise libraries. The production version of MCNP already supports the use of coupled multi-group libraries.
6. SOURCE AND SCOPE OF DATA
The library is based on nuclear theory/model calculations with parameterizations obtained by matching calculations with experimental data, mainly using the PSR-125/GNASH statistical/preequilibrium/fission theory code. The library includes neutron- and proton-induced reactions for 1H, 9Be, 12C, 16O, 27Al, 28Si, Fe, W, and 238U and specifies the production cross sections and energy-angle correlated spectra of emitted neutrons, protons, alpha-particles, photons, and other significant charged particles. See reference LA-11753-MS for details.
7. DISCUSSION OF THE DATA RETRIEVAL PROGRAMS
8. DATA FORMAT AND COMPUTER
BCD card images, All computers. ENDF-6 format.
9. TYPICAL RUNNING TIME
Depends on the problem.
10. REFERENCES
a: Included in package:
P.G. Young, E.D. Arthur, M. Bozoian, T.R. England, G.M. Hale, R.J. Labaive, R.C. Little, R.E. MacFarlane, D.G. Madland, R.T. Perry, and W.B. Wilson, "Transport Data Libraries for Incident Proton and Neutron Energies to 100-MeV" LA-11753-MS (July 1990).
b: Background information:
E.D. Arthur, "The GNASH Preequilibrium-Statistical Model Code," lectures presented during the Workshop on Applied Nuclear Theory and Nuclear Model Calculations for Nuclear Technology Applications," International Centre for Theoretical Physics, Triest, Italy, 15 February - 18 March 1988 (LA-UR 88-283).
P.G. Young, E.D. Arthur, and M.B. Chadwick, "Comprehensive Nuclear Model Calculations: Introduction to the Theory and Use of the GNASH Code," lectures presented during the Workshop on Computation and Analysis of Nuclear Data Relevant to Nuclear Energy and Safety," International Centre for Theoretical Physics, Triest, Italy, 10 February - 13 March 1992 (LA-UR 92-205).
R.E. MacFarlane, D.W. Muir, and R.M. Boicourt, "The NJOY Nuclear Data Processing System," Los Alamos National Laboratory report LA-9303-M, (1982) v. I and II, (1987) v. III, (1985) v. IV.
R.E. MacFarlane, "Introducing NJOY 89," Presented at the OECD Seminar-Workshop on NJOY and THERMIS. Nuclear Energy Agency Data Bank, Saclay, France, June 20-21, 1989 [LA-UR-89-2057 (1989)].
J.F. Briesmeister, Ed., "MCNP - A General Monte Carlo Code for Neutron and Photon Transport, Version 3A," Los Alamos National Laboratory manual LA-7396-M, Rev. 2 (Sept. 1986).
J.F. Briesmeister, "MCNP3B Newsletter," LANL Memo. X-6:JFB-88-292 (July 18, 1988).
11. CONTENTS OF LIBRARY
Included are the referenced document and libraries transmitted on 2 5.25-inch DS/HD (1.2MB) diskettes in DOS compressed format.
12. DATE OF ABSTRACT
July 1993.
KEYWORDS: EVALUATED NEUTRON CROSS SECTIONS