RSICC CODE PACKAGE PSR-528

 

1.  NAME AND TITLE

CEAR-PPU: Code System for Monte Carlo Simulation of Detector Pulse Pile Up.

 

2.  CONTRIBUTORS

Department of Nuclear Engineering, North Carolina State University, Raleigh, North Carolina.

 

3.  CODING LANGUAGE AND COMPUTER

Fortran 77; PC Windows (P00528PC58600).

 

4.  NATURE OF PROBLEM SOLVED

The Monte Carlo simulation code CEARPPU was developed to simulate pulse pile up spectra for high counting rates from given true spectra. In this simulation, the exponential pulse interval distribution is used; and the multichannel analyzer (MCA) is assumed to operate perfectly in obtaining and scoring the first local maximum from a sum pulse.

 

5.  METHOD OF SOLUTION

Forcing and other variance reduction techniques are used to accelerate the simulation process. Simulation results showed excellent agreement with benchmark measurements with an Fe-55 source and a Si(Li) detector. Use of this code in conjunction with a Monte Carlo code that simulates true spectral responses will allow one to simulate the actual pulse height spectra obtained for radiation analyzer systems taken at high counting rates with a large amount of spectral distortion. This, in turn, will allow the use of a suitable nonlinear approach for the routine analysis of in vivo medical or on-line process samples at very high counting rates.

 

6.  RESTRICTIONS OR LIMITATIONS

None noted.

 

7.  TYPICAL RUNNING TIME

Each test case runs in about 1 minute on a 1.4Ghz Pentium IV.

 

8.  COMPUTER HARDWARE REQUIREMENTS

Only the Windows PC executable is provided, so the code cannot be run on other computers.

 

9.  COMPUTER SOFTWARE REQUIREMENTS

The Lahey/Fujitsu Fortran 95 Compiler Release 5.50a on Windows XP was used to create the included executable. The Fortran source is not included.

 

 

 

 

 

 

10. REFERENCES

a  included in package:

R. P. Gardner, S. H. Lee, W. Guo, and F. Li, “CEAR-PPU User's Guide: A Monte Carlo Code for Predicting Pulse Pile-up Distortion for High Counting-Rate Radiation Spectra,” Center for Engineering Applications of Radioisotopes, North Carolina State University (February 2004).

 

b  background reference:

R.P. Gardner and S. H. Lee, "Monte Carlo Simulation of Pulse Pile Up." Advances in X-ray Analysis, 41, pp. 941-950 (1999).

 

11. CONTENTS OF CODE PACKAGE

The package is transmitted on a CD in a WinZIP file that contains the referenced document in 10.a, the CEAR-PPU Windows executable and test cases.

 

12. DATE OF ABSTRACT

September 2004

 

KEYWORDS: DETECTOR RESPONSE; MONTE CARLO