1. NAME AND TITLE

SUPERTOG-LTT: A Modification of PSR-13/SUPERTOG-III Applied to Libraries with Tabulated Elastic Scattering and Anistropy Densities.

2. CONTRIBUTOR

Institute of Nuclear Power, Bulgarian Academy of Sciences, Sofia, Bulgaria.

3. CODING LANGUAGE AND COMPUTER

Fortran IV; IBM 360.

4. NATURE OF THE PROBLEM SOLVED

In calculating the matrix for intergroup elastic-scattering transitions using SUPERTOG programs, it is necessary that the data on the anisotropy of the elastic scattering be given in terms of the coefficients for a Legendre polynomial expansion of the density function. However, for all the material in the ENDL library and for some of the material in ENDF/B-IV, the information on the scattering anisotropy is given in the form of tabulated values of the actual density function. Existing versions of the SUPERTOG program cannot be used for these materials.

5. METHOD OF SOLUTION

SUPERTOG-LTT is a modification of PSR-13/SUPERTOG-III which enables us to calculate the elastic-scattering matrix in either of the two ways the anistropy may be given. With this method, which is based on an approximation by means of orthonormal polynomials, it is possible to calculate the coefficients in the Legendre polynomial expansion of the density function during the operation of the actual program. In fact, this procedure takes less than 15% of the total running time of the SUPERTOG programs.

6. RESTRICTIONS OR LIMITATIONS

In accordance with the requirements of the algorithms followed in SUPERTOG-III, the order of the Legendre polynomial expansion of the function p(mu,E) should not exceed 30 (not more than 31 coefficients, including the zeroth).

7. TYPICAL RUNNING TIME

No study has been made by RSIC of typical running times for SUPERTOG-LTT.

8. COMPUTER HARDWARE REQUIREMENTS

SUPERTOG-LTT was processed on an IBM 3033 computer at Oak Ridge National Laboratory.

9. COMPUTER SOFTWARE REQUIREMENTS

A Fortran IV compiler is required.

10. REFERENCE

G. Bojkov, V. Gadzhokov, K. Ilieva, "Modification of the SUPERTOG Program Applied to Libraries with Tabulated Elastic-Scattering Anisotropy Densities," INDC-6/GV (February 1982).

11. CONTENTS OF CODE PACKAGE

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

12. DATE OF ABSTRACT

January 1986.