1. NAME AND TITLE

CASTHY: Statistical Model Calculation for Neutron Cross Sections and Capture Gamma-Ray Spectra.

2. CONTRIBUTOR

Japan Atomic Energy Research Institute, Tokai-mura, Japan.

3. CODING LANGUAGE AND COMPUTER/OPERATING SYSTEM

Fortran 77, FACOM computers and IBM RISC 6000.

4. NATURE OF PROBLEM SOLVED

This code has been utilized as a tool for nuclear data evaluations. It is used to calculate neutron cross sections of total, shape elastic scattering and compound nucleus formation with the optical model, and compound elastic scattering, inelastic scattering and capture cross sections by the statistical model applying Hauser-Feshbach and/or Moldauer formula. The other cross sections such as the (n,2n), (n,p), (n,f) reactions are treated as cross sections of competing processes, and their sum is given through input data. This code calculates also capture gamma-ray spectra. Branching ratio for primary transition can be treated in a particular way, if necessary.

5. METHOD OF SOLUTION

The total transmission coefficient is modified so that the total reaction cross section obtained by using the optical model may be conserved. The transmission coefficients for neutrons and gamma-rays are rewritten by considering an effect of (n,gamma-n') process.

6. RESTRICTIONS OR LIMITATIONS

For the normalization of cross section, the normalization energy point should be included in the incident energy points of input data. Some other limitations exist depending on options.

7. TYPICAL RUNNING TIME

On an IBM RISC system 550, sample problems 1, 2, and 3 took 14.6, 15.8 and 86.9 seconds respectively.

8. COMPUTER HARDWARE REQUIREMENTS

The code was developed on the FACOM computers and tested on the IBM RISC 6000.

9. COMPUTER SOFTWARE REQUIREMENTS

The code was written in Fortran 77 and tested using the xlf Fortran compiler under the AIX 3.1 operating system on the IBM RISC 6000.

10. REFERENCE

S. Igarasi and T. Fukahori, "Program CASTHY - Statistical Model Calculation for Neutron Cross Sections and Gamma Ray Spectrum," JAERI-1321 (March 1991).

11. CONTENTS OF CODE PACKAGE

Included are the referenced document and one DS/HD (1.2MB) 5.25-in. diskette which includes the source files, sample input and output.

12. DATE OF ABSTRACT

September 1992.