DLC-0017 ZZ-DLC-17/NOX.

1. NAME OR DESIGNATION OF PROGRAM:  ZZ-DLC-17/NOX. 119-group P5 coupled neutron and secondary gamma-ray cross section data for nitrogen and oxygen.

3. NATURE OF PHYSICAL PROBLEM SOLVED

  FORMAT: ANISN, DOT, or MORSE

NUMBER OF GROUPS: Coupled 86 neutron and 33 gamma-ray energy group  cross sections

  NUCLIDES: air (N, and O,)

  ORIGIN: DNA Working Cross Section Library

WEIGHTING SPECTRUM: Cross section values for the neutron thermal group (86) were determined by assuming a Maxwellian weighting function with a constant scattering cross section and a 1/v absorption cross section.

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DLC-17 is suitable for multigroup neutron, gamma-ray, or coupled neutron and gamma-ray transport calculations in nitrogen, oxygen, or air. The retrieval program manipulates the data so that it can be used in codes such as ANISN, DOT, or MORSE.
The coupled 86 neutron and 33 gamma-ray energy group cross sections were produced by members of the ORNL mathematics division.  The neutron multigroup data were produced with SUPERTOG, the neutron to gamma-ray group transfer matrices with a modified version of NUSECT, and the gamma-ray multigroup data with MUG. NUSECT is the cross section generator for O6R , but modifications had to be made to the version in the distributed code package to generate the desired gamma-ray production matrices.

4. METHOD OF SOLUTION

This data represents a P5 Legendre expansion approximation for neutron elastic scattering and gamma-ray Compton scattering.
Inelastic neutron scatter and gamma-ray production are treated as isotropic.
Cross section values for the neutron thermal group (86) were determined by assuming a Maxwellian weighting function with a constant scattering cross section and a 1/v absorption cross section.
The 86 neutron groups cover the energy range from 15 Mev to thermal and the group structure was chosen to represent the variation in the nitrogen total cross section. The 33 gamma-ray groups span the energy range from 10 to 0.01 MeV. The gamma-ray group structure was chosen with one group of width 0.2 MeV containing each nitrogen resolved line and one group of varying energy width between adjacent resolved lines.
The neutron interaction secondary gamma-ray production, and gamma-ray interaction multigroup data were generated from recent evaluations by Young and Foster. The evaluations are part of the DNA working cross section library, and the identification designations are DNA MAT 4133, MOD 1 for nitrogen and DNA MAT 4134,  MOD 0 for oxygen.

6. TYPICAL RUNNING TIME

To read the NOX data from a card image tape and rewrite it on an unformatted tape requires 14 seconds on the IBM 360/91.

7. UNUSUAL FEATURES: UNUSUAL FEATURES OF THE PROGRAM

8. RELATED AND AUXILIARY PROGRAMS

LIBGEN is a modified version of the  library generation routine which is available in the ANISN code package. This version will read data from a card image tape, the mode by which NOX is distributed, and write an unformatted tape for  direct use with ANISN.

10. REFERENCES

- E.A. Straker and B. J. McGregor:
  'A Calculation of Gamma-Ray Production and Transport in Liquid
  Nitrogen'
  ORNL-TM-3635 (December 1971).
- L.R. Williams:
  'Input Description for LIBGEN'
  Informal Notes (1972).
- G.M. Reynolds and S.M. Sperling:
  'A Re-Analysis of Secondary Gamma-Ray Spectra Produced in Liquid
  Nitrogen by 14 MeV Neutrons'
  DNA 2831F or SAI-71-550-LJ (March 1972).

11. HARDWARE REQUIREMENTS: MACHINE REQUIREMENTS

13. SOFTWARE REQUIREMENTS: OPERATING SYSTEM OR MONITOR UNDER WHICH PROGRAM IS EXECUTED

14. ANY OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS:  The  current version of DLC-17 is dated August 1972.

15. NAME AND ESTABLISHMENT OF AUTHOR: Oak Ridge National Laboratory
Oak Ridge, Tennessee, U.S.A.

File name	File description	Records
DLC0017_01.001	119-GRP COUPLED X-SEC (N AND O)	2912
DLC0017_01.002	ANISN LIBRARY ROUTINE (SOURCE)	140
DLC0017_01.003	SAMPLE PROBLEM DD-CARDS AND DATA	5
DLC0017_01.004	SAMPLE PROBLEM OUTPUT	12