Accession Number : AD0478240

Title :   AFWL-ATAC JOINT SHIELDING PROGRAM. PARAMETRIC INVESTIGATION OF THE EXPONENTIAL TRANSFORMATION.

Descriptive Note : Final rept. 1 Oct 64-30 Sep 65,

Corporate Author : GENERAL DYNAMICS/FORT WORTH TEX NUCLEAR AEROSPACE RESEARCH FACILITY

Personal Author(s) : Jones,E. E.

Report Date : JAN 1966

Pagination or Media Count : 99

Abstract : A study was performed to investigate the use of the exponential transformation as applied to thick homogeneous shield systems. The objective was to determine the improvement which the transformation made on results of the Monte Carlo calculations of total neutron flux and of energy and angular distributions of the flux penetrating thick homogeneous shields. Calculations were performed for finite- and infinite-geometry hydrogen shields with two computer programs: SPARC (Slab Penetration and Reflection Calculation) and FMC (Flexible Monte Carlo). Results indicate improvement can be obtained by use of the transformation. For a hydrogen slab which is 10 total mean free paths (100 cm) thick, the standard deviation of the scattered transmitted neutron dose is reduced as much as a factor of 3.9 by use of the transformation. In particular, for thick shields the exponential transformation must be used to calculate valid fluxes. No modification to the computer programs is indicated as a result of this study. It is recommended that further studies be made on the exponential transformation. (Author)

Descriptors :   (*SHIELDING, NEUTRON FLUX), PENETRATION, HYDROGEN, NUMERICAL METHODS AND PROCEDURES, COMPUTER PROGRAMMING, MONTE CARLO METHOD, SPECIAL FUNCTIONS(MATHEMATICAL), STATISTICAL ANALYSIS, NUCLEAR CROSS SECTIONS, EQUATIONS, NEUTRON TRANSPORT THEORY, TABLES(DATA), GEOMETRIC FORMS

Subject Categories : Nuclear Physics & Elementary Particle Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE