Optical Model Theory Of Nuclear Reactions In The Study

With the prominent development of nuclear science,the requirements of the nuclear technology application to nuclear reaction data,which are induced by charged particle in medium energy range,are increasing,and plenty of corresponding theoretical and experimental research are appeared.The optical model is the foundation and starting point for all nuclear model theoretical calculations.In order to obtain reliable nuclear data for technology application,it is necessary to do some deep and detailed research on optical models and optical potentials.In this dissertation,we plan to systematically research optical models and optical potentials in four topics:(1) Based on the existing experimental data for triton as projectile,through the improvement of the potential well depth and geometrical parameters of the present triton optical potentials,we obtained a set of optimal global triton optical potential parameters,which can be used to nuclear reaction which is below 40 MeV and the targets in the range ⁴⁸Ca-²³²Th(as well as ¹⁹F and ²⁷Al).And this set of triton optical potential parameters will be the foundation and starting point for investigation of triton induced nuclear reaction.(2) For nucleon as projectile,based on effective Skyrme force,through the approach of nuclear matter approximation,Q.Shen et al gave the analytical formula for calculating the semi-microcosmic nucleon optical potentials.We have done the comparing calculations between the semi-microcosmic proton optical potentials corresponding to 14 sets of Skyrme force parameters and two sets of global proton phenomenological optical potentials,and find one best set of Skyrme force parameters for constructing semi-microcosmic proton optical potential.Because this kind of semimicrocosmic proton optical potential has solid theoretical foundation,we can with full confidence use it to calculate and evaluate nuclear data for those nuclei which are lack of or without experimental data,especially for those nuclei which are far away from the beta-stability line.(3) Based on the existing experimental data for deuteron as projectile and the folding optical model,we obtain the folding deuteron optical potentials from nucleon optical potentials through the folding integral.As for the nucleon optical potentials, we choose two sets of global nucleon phenomenological optical potentials and Shen's semi-microcosmic nucleon optical potential corresponding to 8 sets of Skyrme force parameters.We have done comprehensive comparing calculations among all these folding deuteron optical potentials,and find one best set of Skyrme force parameters for constructing the folding deuteron optical potential in the framework of folding optical model.Because the semi-microcosmic nucleon optical potentials and the folding optical model have solid theoretical foundation,we can with full confidence use the folding deuteron optical potential corresponding to this best set of Skyrme force parameters to do some nuclear model calculations for the nuclei which are lack of or without experimental data,especially for the nuclei which are far away from the betastability line.Through the work in(2),(3) and the work of Shen et al,we can draw the conclusion:for neutron,proton and deuteron as projectiles,SKαis the common best set of Skyrme force parameters for constructing optical potentials of those particles.(4) Based on the existing experimental data for proton as projectile,through the improvement of the dispersive optical model,we obtained one set of optimal global dispersive optical potential for proton as projectile in the energy region up to 200 MeV with the target mass region 24≤A≤209.And this set of proton optical potential parameters will be the foundation and starting point for investigation of proton induced nuclear reaction,it can also be used in the calculations concerning shell model.