1. NAME AND TITLE

ALPS: Alpha Spectrum Analysis Code System.

2. CONTRIBUTOR

Japan Atomic Energy Research Institute, Tokai, Ibaraki, Japan.

3. CODING LANGUAGE AND COMPUTER

Fortran IV; FACOM 230-75.

4. NATURE OF PROBLEM SOLVED

ALPS analyzes alpha spectra taken with solid-state detectors to extract information on the peak intensities and energies. It was based on the gamma-ray spectrum analyzing code PSR-84/BOB73 and, therefore, the structure is quite similar, except for the peak-fitting part.

5. METHOD OF SOLUTION

ALPS carries out the peak finding by the photopeak method, generates the line-shape function consisting of the Gaussian and the exponential function of the first and/or second order, and decomposes the peak compound by the function-minimizing fitting method on the basis of the above-mentioned line-shape function. The alpha line shape function is approximated with a Gaussian on the high-energy side smoothly connected to an exponential function for the loose tail on the low-energy side. Parameters describing the line shape function are determined separately for individual peak compounds in the spectrum.

6. RESTRICTIONS OR LIMITATIONS

The acceptable spectrum size is up to 4100 channels, the total number of the peaks contained should not be more than 50, and the maximum number of the peak multiplicity is 19.

7. TYPICAL RUNNING TIME

For the case of a spectrum with medium complexity, ALPS runs in less than 10 seconds.

8. COMPUTER HARDWARE REQUIREMENTS

ALPS is operable on the FACOM 230-75 computer. It uses 118 K words of storage.

9. COMPUTER SOFTWARE REQUIREMENTS

A Fortran IV compiler is required.

10. REFERENCES

Hiroshi Baba,, "A Computer Program for Alpha Spectrum Analysis," Nucl. Instr. and Meth. 148 (1978) 173-178.

"Input Data Notes."

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

March 1984.