**1. NAME AND TITLE**

ACAT: Monte Carlo Simulation of Atomic Collisions in Amorphous Targets in the Binary
Collision Approximation.

**2. CONTRIBUTOR**

Okayama University of Science, Okayama, Japan.

**3. CODING LANGUAGE AND COMPUTER**

Fortran 77; Facom 380S and IBM 3033.

**4. NATURE OF PROBLEM SOLVED**

ACAT calculates various phenomena such as sputtering, reflection, range distribution and damage
distribution associated with atomic collisions in amorphous targets.

**5. METHOD OF SOLUTION**

ACAT is based on the binary collision approximation in the Monte Carlo simulation of atomic
collisions in solids. An amorphous target is simulated employing the cell model in which a target atom
is randomly distributed in each unit cubic cell of which the lattice constant is the inverse cube root of
the atomic density.

**6. RESTRICTIONS OR LIMITATIONS**

In the ACAT program one can treat a three layer medium composed of five elements.

**7. TYPICAL RUNNING TIME**

On the IBM 3033 sample problem 1 ran in less than 16 minutes, sample problem 2 ran in less than
5 minutes, and sample problem 3 ran in less than 25 minutes.

**8. COMPUTER HARDWARE REQUIREMENTS**

ACAT was developed on the Facom 380S and also runs on the IBM 3033. ACAT is transportable
and can be run on most computers with at least 2200 K of memory.

**9. COMPUTER SOFTWARE REQUIREMENTS**

A Fortran 77 compiler is required. The code was run at RSIC on the IBM 3033 under the MVS
operating system using the VS compiler.

**10. REFERENCE**

Y. Yamamura, "ACAT: Computer Simulation of Atomic Collisions in Amorphous Target,"
Okayama University of Science, Okayama, Japan.

**11. CONTENTS OF CODE PACKAGE**

Included is the referenced document and one (1.2MB) DOS diskette which contains the source
code, sample JCL, input and output.

**12. DATE OF ABSTRACT**

March 1988.

**KEYWORDS: ** MONTE CARLO; RADIATION DAMAGE