**1. NAME AND TITLE**

MUXS: Generator of Multigroup Cross Sections for Charged Particle Transport
Problems.

**AUXILIARY PROGRAM**

ANISN-ORNL: Multigroup One-Dimensional Discrete Ordinates Transport Code System with
Anisotropic Scattering.

**2. CONTRIBUTOR**

Computer Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee.

**3. CODING LANGUAGE AND COMPUTER**

Fortran IV, Assembler Language; IBM 3033.

**4. NATURE OF PROBLEM SOLVED**

MUXS generates multigroup cross sections for charged particle transport problems. The cross
sections generated by MUXS can be used in many multigroup transport codes, with minor
modifications to these codes, to calculate sputtering yields, reflection coefficients, penetration
distances, etc.

**5. METHOD OF SOLUTION**

Since treatment of the many small deflections of the ion using a Legendre expansion of the
differential scattering cross section is simply not feasible, MUXS accounts for the energy lost by the
ion when deflected through small angles with a continuous slowing down term. This approach ignores
the directional change due to these interactions. All electronic interactions with the ion are included
in this term. Interactions with the nuclei that result in a scattering angle that is less than a prescribed
angle @Thetan are also treated as continuous interactions. Scatterings through angles larger than
Thetan are termed "discrete interactions" and are included in the evaluation of the multigroup total and
scattering cross sections.

**6. RESTRICTIONS OR LIMITATIONS**

None noted.

**7. TYPICAL RUNNING TIME**

On an IBM 3033 computer operating under MVS, MUXS required 25 sec and 834 I/O and the
ANISN-ORNL sputtering sample problem required 5 min. and 700 I/O.

**8. COMPUTER HARDWARE REQUIREMENTS**

MUXS is operable on the IBM 3033 computers and requires 540 K of memory. The ANISN-ORNL sputtering calculation requires 900 K.

**9. COMPUTER SOFTWARE REQUIREMENTS**

A Fortran IV compiler is required.

**10. REFERENCE**

T. J. Hoffman, M. T. Robinson, and H. L. Dodds, Jr., "MUXS: A Code to Generate Multigroup
Cross Sections for Sputtering Calculations," ORNL/CSD/TM-185 (October 1982).

**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**

April 1984.

**KEYWORD**: CHARGED PARTICLE CROSS SECTION PROCESSING