RSIC COMPUTER CODE PSR-085 

1. NAME AND TITLE 
NAISAP: Theory and Use of Gamma-Ray Spectrum Analysis Codes for NaI(Tl) Detectors. 

2. CONTRIBUTOR 
Japan Atomic Energy Research Institute, Tokai Research Establishment, 
Ibaraki-Ken, Japan. 

3. CODING LANGUAGE AND COMPUTER 
Fortran IV; FACOM 230-60. 

4. NATURE OF PROBLEM SOLVED 
NAISAP analyzes the NaI(Tl) gamma-ray spectrum and other types of spectra to determine 
the energies and intensities of the peaks detected. The spectrum is plotted in option. 

5. METHOD OF SOLUTION 
The analysis is carried out by the photopeak method on the basis of the NaI(Tl) 
response function represented in an analytical form. The peak search is based on the 
first derivative method accompanied with various peak shape tests. The usual least 
squares method is adopted for resolving the complex of peaks. Values of the parameters 
for constructing the NaI(Tl) response are stored as data for two detector sizes: 
1-3/4" phi x 2" and 3" phi x 3." 

6. RESTRICTIONS OR LIMITATIONS 
NAISAP accepts a spectrum of a maximum of 1024 channels with up to 49 peaks. Response 
functions of detectors with dimensions different from those mentioned above must be 
given by the user in specifying the parameters as functions of the photon energy. 

7. TYPICAL RUNNING TIME 
NAISAP requires approximately one second for the analysis of each peak. 

8. COMPUTER HARDWARE REQUIREMENTS 
NAISAP is operable on the FACOM 230-60 computer. A 76 K word memory is required. 
A CALCOMP plotter is optional. 

9. COMPUTER SOFTWARE REQUIREMENTS 
A Fortran IV compiler is required. 

10. REFERENCES 
H. Baba, T. Sekine, S. Baba, and H. Okashita, "A Method of the Gamma-Ray Spectrum 
Analysis: Fortran IV Programs 'BOB 73' for Ge(Li) Detectors and 'NAISAP' for NaI(Tl) 
Detectors," JAERI 1227 (June 1973). 

T. Sekine, S. Baba, H. Baba, "Analytical Functions Representing Response Functions of 
NaI(Tl) Detector Systems to Gamma Rays," ORNL-tr-2941/JAERI-M 4590 (September 1971). 

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. 

KEYWORDS: DATA PROCESSING, SPECTRA; GAMMA-RAY SPECTRUM ANALYSIS; UNFOLDING