Nuclear Models Relevant to Evaluation

Abstract

The widespread use of nuclear models continues in Ihe creation of data evaluations. The reasons include exte~ion of data evaluations IO higher energies, creation of data libraries for isoropic components of narura.i marerials, and production of evaluations for mdioactive trrget species. In these cases, ex~rirnental dam am often sparse or nonexistem. As LIti trend continues, the nuclear mmlels employed in evaluation work move rowarcts more microscopictiy-based theoretical methods, prompted in part by the availability of increasingly powerfuJ carnputational resources.Advances m nuclear models applicable to evaluation w W be reviewed. 'fhese include advances in optical model heo~, microscopic and phenomenological slate and level density theory, unikd modch that consisterrdy describe W equilibrium and nonequilibrium reaction mechanisms, and improved methodologies for calculation of prompt radiation from fsssion. LuufdwltMReviews by Uld [I], Gardner [2], and Young [31 at earlier intem~rional nuclear data conferences have stressed the increucd arrd imporrmt role that nuclcds models play in the provbion of daia for a variery of applications. This crec ontinues with~heorelical calculations r~resenling a ma 'or J component required for development of evaluated data f es for ENDF-VI, JENDL, JEP, and rho BROND libraries, These dma systems have expanded their scopo beyond the irrcorporatlon of neutron-induced reaction dm for energies blow 2L .MeV, Extensions include provision of reaction data for incident charged-particles and higher energy data, In r.hesc extensions, nuclear models have played a signiflcam and major role.Applications such as nuclear wute transmutation, radiwion protection for manned spsce exploration, and radiotherapy involving energetic n .Ieon