1. NAME AND TITLE OF DATA LIBRARY

AMPX01(104,22): 126-Group Coupled Neutron and Gamma-Ray Transport Cross-Section Data Generated by AMPX.

2. NAME AND TITLE OF DATA RETRIEVAL PROGRAM

LIBGEN: A Computer Program to Generate an Unformatted Cross-Section Tape for Input to ANISN.

3. CONTRIBUTOR

Oak Ridge National Laboratory, Oak Ridge, Tennessee.

4. HISTORICAL BACKGROUND AND INFORMATION

The data in DLC-27/AMPX01(104,22) were generated for use in studies of neutron and secondary gamma-ray albedo for various types of concrete by G. P. Cavanaugh. The data were generated using the AMPX code and very recent cross section evaluations and the resulting coupled library represents the state of the art at this time. The data are recommended over that generated in 1969 for the DLC-9/FARS Library for studies of neutron and secondary gamma-ray transport in concrete-like materials.

5. APPLICATION OF THE DATA

The DLC-27/AMPX01(104,22) library was generated for use in albedo studies of neutrons incident on various types of concrete. It is probably also suitable for neutron, gamma-ray, or coupled neutron and secondary gamma-ray transport through concrete-like materials.

The retrieval program supplied with the library can convert the data into the cross section input forms required by codes such as CCC-82/ANISN-CEA, CCC-89/DOT, and CCC-127/MORSE.

6. SOURCE AND SCOPE OF DATA

AMPX01(104,22) is a coupled set of neutron and gamma-ray cross sections for elements N, O, Al, H, K, Si, Ca, C, and Fe.

The AMPX system was utilized to generate the entire coupled library in a single computer run. For all materials except C and K, the basic evaluated data from which the multigroup library was derived was the Defense Nuclear Agency Working Cross Section Library dated September 1972. The potassium data came from ENDF/B-III. The carbon was ENDF/B-III with photon production added to describe a single inelastically and isotropically produced gamma-ray.

The neutron energy range (15 MeV to thermal) is described by 104 groups having the same energy structure as used for DLC-9/FARS. The gamma-ray energy range (10 MeV to 0.02 MeV) is described by 22 energy groups. For generating the multigroup neutron interaction and gamma-ray production cross sections, the assumption was made that the neutron flux variation (weighting function) was 1/E in the fast range and Maxwellian (300 K) in the thermal range. For the gamma-ray interaction multigroup cross section generation, a flat weighting function was used. The neutron and gamma-ray scattering processes are represented by a P₅ Legendre expansion. The library is written as card images in ANISN (FIDO) format.

7. DISCUSSION OF THE DATA RETRIEVAL PROGRAM

LIBGEN is a modified version of the Library Generation Routine available in the CCC-82/ANISN-CEA code package. This version reads the card image AMPX01 tape and converts it into an unformatted library tape for direct use in CCC-82/ANISN-CEA, CCC-89/DOT, or CCC-127/MORSE.

8. DATA FORMAT AND COMPUTER

BCD/EBCDIC card images; IBM 360/370.

9. TYPICAL RUNNING TIME

On an IBM 360/91 computer, it requires 1 minute to convert to an unformatted tape using the retrieval program.

10. REFERENCES

a. Included in the documentation:

J. E. White, "104N-22G Coupled Neutron and Gamma-Ray Library Generated with AMPX," Informal note (1973).

L. R. Williams, "Input Description for LIBGEN," Informal note (1972).

b. Background information:

G. P. Cavanaugh, Ph.D. Dissertation from the University of Illinois (to be published).

11. CONTENTS OF LIBRARY

Included are the referenced documents (10.a) and one (1.2MB) DOS diskette which contains the library, the retrieval program and sample problem input and output.

12. DATE OF ABSTRACT

September 1973; revised September 1974, April 1976; reviewed May 1984.