INVESTIGATION

STANDARD RADIATION TRANSPORT ANALYSIS TECHNIQUES WILL BE USED TO STUDY THE EFFECT OF SHIELD CONFIGURATION (SHAPE FACTORS, MATERIAL GRADIENTS) ON TARGET DOSE. SUCH A STUDY WILL ASSIST IN DETERMINING OPTIMAL SHIELD CONFIGURATIONS FOR PROTECTION OF MILITARY VEHICLES SUCH AS THE SMALL ICBM HARD MOBILE LAUNCHER AGAINST GAMMA RADIATION FROM NUCLEAR WEAPONS. PARTICULAR ATTENTION WILL BE PAID TO THE INCOR-PORATION OF STREAMING PATHS IN THE SHIELD, IN ORDER TO DIVERT GAMMA RAYS AWAY FROM CRITICAL AREAS. THE POTENTIAL SAVINGS (REDUCED DOSE FOR GIVEN SHIELD MASS OR REDUCE MASS FOR A SPECIFIED TARGET DOSE) ARE SIGNIFICANT. THE GOOD-GEOMETRY AND LAYERED-SHIELD PRINCIPLES PREVIOUSLY DEVELOPED BY THE APPLICANT WILL BE REFINED BY EVALUATING ABSORPTION AND SCATTERING INDICES, BY CONSIDERING RADIAL AND AXIAL GRADIENTS (ATOMIC NUMBER AND/OR DENSITY) IN INDIVIDUAL SHIELD MEMBERS AND BY INCORPORATING PLEATING OR RIBBING IN CONCENTRIC MULTILAYER SHIELDS TO GIVE PROTECTION OVER A SOLID ANGLE APPROACHING A HALFSPACE. IN PHASE II, SHIELDING AGAINST NEUTRONS WILL BE CONSIDERED AND A SHIELDING OPTIMIZATION STRATEGY FOR EARLY INTEGRATION INTO THE OVERALL DESIGN PROCESS WILL BE DEVELOPED.