RSIC COMPUTER CODE PSR-045

1. NAME AND TITLE

GAUSS: A Code system for Analysis of Gamma-Ray Spectra from Ge(Li) Spectrometers.

GAUSS V (PSR-45A) was the original GAUSS package in the RSIC collection and was written for the IBM 360/75 computer. This original package was extended to include GAUSS VII (PSR-45B) which runs on the CDC computer. The two have now been combined into this one package and called GAUSS.

2. CONTRIBUTORS

Aerojet Nuclear Company, Idaho Falls, Idaho (A).

EG&G Idaho, Inc., Idaho Falls, Idaho (B).

3. CODING LANGUAGE AND COMPUTER

Fortran IV; IBM 360/370 (A) AND CDC (B).

4. NATURE OF PROBLEM SOLVED

GAUSS determines gamma-ray energies and intensities from spectra obtained with a Ge(Li) detector and a multichannel pulse-height analysis system.

5. METHOD OF SOLUTION

The preliminary portions of the program can determine the energy and width calibration equations, locate individual peaks and define "peak regions" that are significantly above the local spectral background. The user may edit these lists of peaks and regions. Each peak region is fitted with one or more components in which the peaks are represented by a Gaussian function or a Gaussian with one or two additive exponential tails on the low-energy side and one on the high-energy side. A step-like background function can be used with each component. The program will automatically recycle to add one or more components to a region if needed to improve the fit. The gamma-ray energies and intensities are computed from the resulting Gaussian positions and peak areas. To allow the user to determine the best results, the results from the analyses for each region with different numbers of components can be printed and line-printer plots of the fits to the data can be made.

6. RESTRICTIONS OR LIMITATIONS

GAUSS will handle spectra of up to 4096 channels with up to 300 peaks and 50 energy calibration lines.

The quality of the results depends primarily on the ability of the program to define a good spectral region for each analysis and the ability to recycle to determine the proper number of components.

7. TYPICAL RUNNING TIME

Typical spectra can be analyzed at a rate of approximately 5 per minute.

8. COMPUTER HARDWARE REQUIREMENTS

GAUSS is operable on the IBM 360/370 computer (A) or the CDC computer (B). A printer and punch are required.

9. COMPUTER SOFTWARE REQUIREMENTS

A Fortran compiler is required.

10. REFERENCES

R. G. Helmer and M. H. Putnam, "GAUSS V, A Computer Program for the Analysis of Gamma-Ray Spectra from Ge(Li) Spectrometers," ANCR-1043 (January 1972).

C. M. McCullagh and R. G. Helmer, "GAUSS VII. A Computer Program for the Analysis of Gamma-Ray Spectra from Ge Semiconductor Spectrometers, Informal Report," EGG-PHYS-5890 (October 1982).

11. CONTENTS OF CODE PACKAGE

Included are the referenced document and one (1.2MB) DOS diskette which contains the source codes and sample problem input and output.

12. DATE OF ABSTRACT

October 1983.