1. NAME AND TITLE

FEMB: A Two-Dimensional Diffusion Theory Finite Element Program.

2. CONTRIBUTOR

Riso National Laboratory, Roskilde, Denmark.

3. CODING LANGUAGE AND COMPUTER

ALGOL; BURROUGHS 6700.

4. NATURE OF PROBLEM SOLVED

FEMB computes the neutron flux and multiplication in a two-dimensional (x-y) geometry.

5. METHOD OF SOLUTION

FEMB solves the diffusion-theory equations using finite elements for one group at a time using the ordinary power iteration technique. The equation for one group is solved by a pointwise successive overrelaxation technique. There is only one inner iteration for each outer one.

The iterations are accelerated by extrapolation for removal of the dominating error-mode. The iterations are stopped when the local error is less than a given input parameter (eps).

6. RESTRICTIONS OR LIMITATIONS

It is not a fast program, and therefore should be used when high precision is needed.

7. TYPICAL RUNNING TIME

No study has been made by RSIC of typical running times for FEMB.

8. COMPUTER HARDWARE REQUIREMENTS

The code is operable on a BORROUGH 6700 computer.

9. COMPUTER SOFTWARE REQUIREMENTS

An ALGOL compiler is required.

10. REFERENCE

I. Misfeldt, "The Program FEMB Users Manual," Riso-M-1929 (March 1977).

11. CONTENTS OF CODE PACKAGE

Included are the referenced document and one (1.2MB) DOS diskette which contains the source code written in ALGOL and the sample problem input.

12. DATE OF ABSTRACT

January 1982.