RSIC COMPUTER CODE PSR-022

1. NAME AND TITLE

RICE: A Program to Calculate Primary Recoil Atom Spectra from ENDF/B Data.

The code package is also available from the Argonne Code Center.

2. CONTRIBUTOR

Oak Ridge National Laboratory, Oak Ridge, Tennessee.

3. CODING LANGUAGE AND COMPUTER

Fortran IV; IBM 360.

4. NATURE OF PROBLEM SOLVED

RICE calculates an energy exchange matrix which describes the probability that a neutron with energy E will produce a recoil atom with energy T in a given material. In addition, it can calculate the primary recoil atom energy spectrum for a given neutron spectrum, the damage cross section for the material, and an optimum lower energy limit for use in comparing the relative damage in different reactor spectra. RICE accepts neutron scattering data directly from the ENDF/B library tapes and, in the case of a resonance nuclide, from a tape generated by PSR-13/SUPERTOG.

5. METHOD OF SOLUTION

The energy transfer matrix is obtained from a solution of the two body kinematic equations. The solution incorporates information on anisotropic elastic scattering and inelastic scattering available from ENDF/B. Damage cross sections and primary recoil spectra are obtained by combining the energy transfer matrix with suitable secondary displacement models and neutron flux spectra.

6. RESTRICTIONS AND LIMITATIONS

RICE lacks the capability of calculating elastic scattering cross sections from resonance parameters. The code SUPERTOG (ORNL-TM-2679) can be used to produce smooth elastic scattering cross sections for RICE in cases where resonance parameters are included in the ENDF/B data. The multigroup codes GAM-II, CCC-82/ANISN, and CCC-123/XSDRN can be used to produce neutron spectra for use in RICE.

RICE does not recognize all of the multiplicity of data formats allowed by ENDF/B. It is programmed to accept the most prevalent formats. These restrictions are described in detail in the program manual. In addition, the neutron energy distribution is restricted to a 99-group representation and the recoil energies are represented by 200 energy groups.

7. TYPICAL RUNNING TIME

Running time for RICE on the IBM 360/75 for one element with all options requested is approximately 10 minutes.

8. COMPUTER HARDWARE REQUIREMENTS

RICE is operable on the IBM 360 computer. Approximately 110,000 words of core storage and five I/O devices, excluding input-output and system requirements, are needed. A plotting routine makes use of ORNL system subroutines and a Calcomp CTR plotter.

9. COMPUTER SOFTWARE REQUIREMENTS

RICE has been run on the IBM OS/360 Operating System with the Fortran H compiler.

10. REFERENCE

J. D. Jenkins, "RICE: A Program to Calculate Primary Recoil Atom Spectra from ENDF/B Data," ORNL-TM-2706 (February 16, 1970).

11. CONTENTS OF CODE PACKAGE

Included are the referenced document and one (1.2MB) DOS diskette which contains the source code and sample problem input and output.

12. DATE OF ABSTRACT

November 1972; revised November 1983.