1. NAME AND TITLE

SAND II: Neutron Flux Spectra Determination by Multiple Foil Activation - Iterative Method. We recommend PSR-345/SNL-SAND-II.

AUXILIARY ROUTINES

CSTAPE: Generates Cross-Section Data Library for Calculation of Foil Activities.

SLACTS: Generates Spectral and Activities Data for SLTAPE.

SLTAPE: Generates Reference Spectrum Data Library.

SAND II: Neutron Flux Spectra Determination.

DIF: Set of Function Routines.

An early version (1968) of SAND was received through the services of the General Electric Company, TEMPO, Data Center, Santa Barbara, California, and Computer Sciences, Richland Washington. Many revisions have been made as the result of user feedback and interaction with the American Society for Testing and Materials (ASTM) Standards Committee E10. Nuclear Technology and Applications and Subcommittee E10.05 Nuclear Radiation Metrology. The SAND II code package is included in the ASTM Proposed Standard Recommended Practices for the Application of Neutron Spectrum Adjusted Methods in Reactor Surveillance. The PC version which was packaged in September 1993 is a conversion of the C00112/I3675/00 release last updated in August 1977.

2. CONTRIBUTORS

Air Force Weapons Laboratory (RTD), Kirtland Air Force Base, New Mexico.

Battelle Memorial Institute Pacific Northwest Laboratory, Richland, Washington.

Atomics International, Canoga Park, California.

TRW Systems Group, TRW, Inc., Redondo Beach, California.

Oak Ridge National Laboratory, Oak Ridge, Tennessee.

Experimental and Mathematical Physics Consultants, Gaithersburg, Maryland.

3. CODING LANGUAGE AND COMPUTER

FORTRAN IV; CDC 6600/7600 C00112/C7600/00 and IBM 360/75/91 C00112/I3675/00 FORTRAN 77; IBM PC C00112/IBMPC/01.

4. NATURE OF PROBLEM SOLVED

Neutron energy spectra are determined by an analysis of experimental activation detector data.

5. METHOD OF SOLUTION

An iterative perturbation method is used to obtain a ``best fit'' neutron flux spectrum for a given input set of infinitely dilute foil activities. The calculational procedure consists of the selection of a known flux spectrum form to serve as the initial approximation to the solution, and subsequent iteration to a form acceptable as an appropriate solution. The solution is specified either as time-integrated flux (fluence) for a pulsed environment or as a flux for a steady-state neutron environment.

A reaction cross-section library is provided with the code.

6. RESTRICTIONS OR LIMITATIONS

None noted.

7. TYPICAL RUNNING TIME

Estimated running time of sample problem: 23 minutes on the IBM 360/75;

PC times on Northgate M86/66: CSTAPE = 16.0 sec.

SLACTS2 = 6.5 sec.

SLACTS3 = 7.0 sec.

SLACTS4 = 26.0 sec.

SLTAPE = 1.5 sec.

SANDII = 75.0 sec. (allowing time to view graphs)

8. COMPUTER HARDWARE REQUIREMENTS

The code is operable on IBM 360/75/91, CDC 6600/7600, and 80386/80486 PCs with a coprocessor.

9. COMPUTER SOFTWARE REQUIREMENTS

Standard FORTRAN IV compilers may be used. The Lahey F77L3/EM32 Fortran compiler version 5.01 was used to create the executables included in the package.

10. REFERENCES

F. B. K. Kam, "Notes to User's" (January 1969).

B. Cross, SAND II/CSTAPE (Memo) (June 1975).

W. N. McElroy, S. Berg, T. Crockett, R. G. Hawkins, "A Computer-Automated Iterative Method for Neutron Flux Spectra Determination by Foil Activation, Vol. I: A Study of the Iterative Method," AFWL-TR-67-41 (September 1967).

S. Berg and W. N. McElroy, "A Computer-Automated Iterative Method for Neutron Flux Spectra Determination by Foil Activation, Vol. II: SAND II (Spectrum Analysis by Neutron Detectors II) and Associated Codes," AFWL-TR-67-41 (September 1967).

W. N. McElroy and S. Berg, "A Computer-Automated Iterative Method for Neutron Flux Spectra Determination by Foil Activation, Vol. IV: Reference Spectrum Library for SAND II," AFWL-TR-67-41 (September 1967).

S. Berg, "Modification of SAND II," BNWL-855 (August 1968).

R. L. Simons and W. N. McElroy, "Evaluated Reference Cross Section Library," BNWL-1312 (May 1970).

M. L. Eaton and W. L. Wilcoxson, "Estimating Strengths of Individual Radioisotopes in a Multiple-Isotope Source," Technical Report R-551.

11. CONTENTS OF CODE PACKAGE

Included are the referenced documents and one (1.2MB) DOS diskette which contains the source codes, data libraries, and input for a sample problem, and an output listing from running the problem for each of the packaged codes and each hardware version. The PC version includes the executables.

12. DATE OF ABSTRACT

May 1969; updated July 1981, September 1991, September 1993, January 1994.