1. NAME AND TITLE

GIP: Group-Organized Cross-Section Input Program.

2. CONTRIBUTOR

Oak Ridge National Laboratory, Oak Ridge, Tennessee.

3. CODING LANGUAGE AND COMPUTER

Fortran 77; IBM PC or PC AT.

4. NATURE OF PROBLEM SOLVED

GIP reads nuclide-organized cross-section libraries prepared for ANISN or DOT and prepares a group-organized library. This has the effect of making ANISN or DOT memory requirements almost independent of the number of energy groups.

5. METHOD OF SOLUTION

A simple multiple-pass sorting technique is used. Only sequential access is used. System routines are relied upon to provide blocking into efficient block sizes.

Data transmission and timing are provided through standard interface routines specified by RRD's de facto Computer Code Coordinating Committee.

6. RESTRICTIONS OR LIMITATIONS

GIP can provide acceptable efficiency if the total volume of data to be output is only a few times the available memory. Truly huge problems must use a random access code such as AXMIX.

7. TYPICAL RUNNING TIME

Running time is widely variable. A 76-group production problem with 48 input nuclides and 8 output mixtures required 0.19 minutes CPU time and 7.3 minutes total time on the IBM 360/91.

8. COMPUTER HARDWARE REQUIREMENTS

GIP is operable on the IBM PC or PC AT and requires about 512 K memory and a math coprocessor.

9. COMPUTER SOFTWARE REQUIREMENTS

GIP was tested on the IBM PC AT under DOS 3.0 using the IBM Personal Computer Professional Fortran compiler, 1.00 Copyright Ryan-McFarland Corp. 1984.

10. REFERENCE

W. A. Rhoades, "The GIP Program for Preparation of Group-Organized Cross-Section Libraries," Informal Notes (April 1978).

11. CONTENTS OF CODE PACKAGE

Included are the referenced document and one (360 K) DOS diskette which contains the source code, sample problem input and output plus executable file.

12. DATE OF ABSTRACT

May 1986, revised April 1989.