1. NAME AND TITLE

MISSIONARY: ENDF/B to NDL Data Format Converter.

2. CONTRIBUTOR

Ministry of Defense, Atomic Weapons Research Establishment, Aldermaston, Reading, England, through the OECD NEA Computer Programme Library (NEA-CPL), Ispra (Varese), Italy.

3. CODING LANGUAGE AND COMPUTER

Fortran IV, Assembler Language; IBM 360/370.

4. NATURE OF PROBLEM SOLVED

MISSIONARY converts data from the Evaluated Nuclear Data File (ENDF/B) format to the Nuclear Data Library (NDL) format.

Where an NDL equivalent exists, MISSIONARY converts neutron cross section data, angular distributions, secondary energy distributions, and nubar. It accepts, but does not process, photon production and reaction data, thermal scattering law data, secondary neutron energy-angle distributions, decay chains, fission product yields, and delayed neutron data. Where data are given at several temperatures, only one is used.

5. METHOD OF SOLUTION

The NDL is almost entirely tabulations whereas the ENDF/B makes more use of parametric forms. MISSIONARY takes the latter forms and generates tabulations as required by the NDL. For example, cross sections can be generated from resonance parameters, angular distributions from Legendre coefficients, or secondary distributions from Maxwellian coefficients. A typical procedure is to calculate values at some obvious points (for example, upper, lower, and most probable energies) and to add points until the tabulation is close enough to the required curve.

A second phase is included where points are omitted if they add little information to the file. Unlike the adding of points, which is controlled by only three input parameters, the omission of points is controlled by parameters different for each type of data, possibly different for each reaction in that type of data, and varying with incident neutron energy.

The data are initially processed in the order they appear on the ENDF/B tape. During manipulation they are re-ordered to be accessible in the order specified for the NDL. The final stage is to write the data out in the detailed card image form of the NDL.

6. RESTRICTIONS OR LIMITATIONS

Reich-Moore and Adler-Adler resonance formulae are not processed. Temperature dependence is ignored. Inelastic scattering is allowed to only 30 discrete levels. There are various storage restrictions which would require recompilation to overcome. The most stringent of these is that a cross section is limited to 5000 data points including those interpolated by the program.

7. TYPICAL RUNNING TIME

On an IBM 360/75, a file without resonances is converted in a few minutes of CPU time. Doppler broadening of the data increases the running time by a great deal.

8. COMPUTER HARDWARE REQUIREMENTS

MISSIONARY is operable on the IBM 360/370 computers.

9. COMPUTER SOFTWARE REQUIREMENTS

Fortran IV and Assembler Language compilers are required. The operating system used is OS/360 with MFT or MVT, VS2.

10. REFERENCE

J. Cameron, "MISSIONARY - A Computer Program to Convert Data in the ENDF Format to the UKAEA Nuclear Data Library Format," AWRE-017/76 (October 1976).

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

March 1984.