RSIC COMPUTER CODE PSR-083

1. NAME AND TITLE

GAMAN: Qualitative and Quantitative Evaluation of Ge(Li) Gamma-Ray Spectra.

2. CONTRIBUTOR

Whiteshell Nuclear Research Establishment, Pinawa, Manitoba, Canada.

3. CODING LANGUAGE AND COMPUTER

Fortran IV and Assembler Language; PDP-10.

4. NATURE OF PROBLEM SOLVED

GAMAN does qualitative and quantitative analyses of gamma-ray spectra from Ge(Li) detectors.

5. METHOD OF SOLUTION

GAMAN "smooths" the spectral data by fitting 5 channel groups of data to a polynomial. The derivative is calculated at the midpoint of each group. A change of sign in the derivative indicates the beginning of a peak. The maximum and minimum values of the derivative are used to check on whether the peak height is statistically significant.

The significant peaks are fitted to a modified Gaussian function using a non-linear least squares procedure. This results in the calculation of the area and centroid of each peak and, by addition of calibration data, the gamma emission rates and energies are calculated and listed.

The listed energies are compared with gamma-ray energies in a library of isotopes and the isotopes present are identified.

The gamma-ray emission rate for each isotope is corrected for gamma-ray abundance and the disintegration rate is calculated.

6. RESTRICTIONS OR LIMITATIONS

None noted.

7. TYPICAL RUNNING TIME

GAMAN runs in < 120 seconds for 30 peaks.

8. COMPUTER HARDWARE REQUIREMENTS

GAMAN is operable on the PDP-10 computer. It requires 64 K of core memory.

9. COMPUTER SOFTWARE REQUIREMENTS

Fortran IV and Assembler Language compilers are required.

10. REFERENCES

"User's Guide for GAMAN 5," Informal Notes.

L. T. Felawka, J. G. Molnar, J. D. Chen and D. G. Boase, "GAMAN - A Computer Program for the Qualitative and Quantitative Evaluation of Ge(Li) Gamma-Ray Spectra," AECL-4217 (January 1973).

11. CONTENTS OF CODE PACKAGE

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

12. DATE OF ABSTRACT

February 1975.