1. NAME AND TITLE

SCINFUL: Scintillator Full Response to Neutron Detection.

AUXILIARY ROUTINE:

SCINSPEC: Reformat SCINFUL Output into Standard Spectrum.

2. CONTRIBUTORS

Oak Ridge National Laboratory, Oak Ridge, Tennessee.

Los Alamos National Laboratory, Los Alamos, New Mexico.

3. CODING LANGUAGE AND COMPUTER

Fortran 77; VAX (P00267D860000), Cray (P00267CYOMP00).

4. NATURE OF PROBLEM SOLVED

SCINFUL uses a few programming techniques of its parent program PSR-014/O5S and includes several new features. SCINFUL is designed to provide a calculated full response anticipated for neutron interactions in either an NE-213 (liquid) or NE-110 (solid) cylindrical detector using Monte Carlo methods. Given a right-circular scintillation neutron detector of either NE-213 or NE-110, SCINFUL computes the full energy response, N(E) vs E, where E is a value of pulse height converted to "light" units. These units are defined in the program. Pulse-height predictions of the code have been compared with measured responses for incident neutron energies between 0.1 and 75 MeV, and the predictions are in good agreement with the measurements.

5. METHOD OF SOLUTION

In the first part of the calculation Monte Carlo techniques and tabulated cross sections for H and energetically available 12C reactions are utilized to determine if an interaction of an incident neutron occurs in the detector. If so, information of this interaction is stored, including coordinates of the collision spot, the direction cosines of the scattered neutron or other light ion, the energy of the colliding neutron, and the particular reaction type. The second part of the calculation follows the history of each colliding neutron, again using Monte Carlo methods, until either the neutron escapes the detector, or loses sufficient energy with respect to an input value, or is absorbed.

6. RESTRICTIONS OR LIMITATIONS

The detector shape must have cylindrical geometry. No external influences (e.g. light piping or canning material) are considered. The range of incident neutron energy is 0.1 to 80 MeV. Only the scintillators NE-213 and NE-110 are considered (although NE-102 is sufficiently similar to NE-110 that one may use NE-110 for comparisons to NE-102 responses). Although gamma-ray interactions are included as part of the total neutron response, program computation for gamma radiation is quite approximate. Present program dimensions limit any computation to a maximum of 100000 histories.

7. TYPICAL RUNNING TIME

On the VAX 8600 running under VAX/VMS Version 4.7, SCINFUL takes about 11 minutes to execute the sample problem. SCINSPEC only takes a few seconds. For a maximum of 100000 histories, approximately 30 CPU minutes on the VAX 11/785 is required. The sample problem ran in about 30 seconds on the Cray XMP-2.

8. COMPUTER HARDWARE REQUIREMENTS

SCINFUL was developed on the VAX 11/785 and tested on an 8600. The Cray version was converted and tested on a Cray X-MP.

9. COMPUTER SOFTWARE REQUIREMENTS

A Fortran 77 compiler is required. VAX/VMS Fortran recognizes eight-character descriptors, and many are used throughout the program. Standard trigometric and other library functions are required. Also needed is a library random-number generator, called RAN(K) in this program. An initial value for K must be specified. A VAX/VMS function IDATE, which returns today's date, is called. The Cray version was run under the CTSS operating system using the CFT compiler linked to the CFTLIB library.

10. REFERENCES

J. K. Dickens, "SCINFUL: A Monte Carlo Based Computer Program to Determine a Scintillator Full Energy Response to Neutron Detection for En Between 0.1 and 80 MeV: User's Manual and Fortran Program Listing," ORNL-6462 (March 1988).

J. K. Dickens, "SCINFUL: A Monte Carlo Based Computer Program to Determine a Scintillator Full Energy Response to Neutron Detection for En Between 0.1 and 80 MeV: Program Development and Comparisons of Program Predictions with Experimental Data," ORNL-6463 (April 1988).

11. CONTENTS OF CODE PACKAGE

Included are the referenced documents and one DS/DD (360 K) diskette which contains the source code, sample problem output from an interactive run and instructions in compressed format.

12. DATE OF ABSTRACT

June 1988, October 1988, March 1989.