Optical Model Analysis Of Elastic Scattering And Direct Reactions

The nucleon optical model is widely used to calculate the elastic scattering cross-sections and polarisations for the interaction of neutrons and protons with atomic nuclei. The optical model potentials not only describe the scattering but also provide the wave functions needed to analyse a wide range of nuclear reactions. They also unify many aspects of nuclear reactions and nuclear structure. This book consists of a comprehensive introduction to the subject and a selection of papers by the author describing the optical model in detail. It contains full references to the original literature with many examples of the application of the model to the analysis of experimental data.

Describes how the processes in stars which produce the chemical elements for planets and life may be reproduced in laboratories.

Direct Nuclear Reactions deals with the theory of direct nuclear reactions, their microscopic aspects, and their effect on the motions of the individual nucleons. The principal results of the theory are described, with emphasis on the approximations involved to understand how well the theory can be expected to hold under specific experimental conditions. Applications to the analysis of experiments are also considered. This book consists of 19 chapters and begins by explaining the difference between direct and compound nuclear reactions. The reader is then introduced to the theory of plane waves, some results of scattering theory, and the phenomenological optical potential. The following chapters focus on form factors and their nuclear structure content; the basis of the optical potential as an effective interaction; reactions such as inelastic single- and two-nucleon transfer reactions; the effect of nuclear correlations; and the role of multiple-step reactions. The theory of inelastic scattering and the relationship between the effective and free interactions are also discussed, along with reactions between heavy ions and the polarizability of nuclear wave functions during a heavy-ion reaction. This monograph will be of interest to nuclear physicists.

The reactions 16 0(d,d) 16 0, 16 0(d,p) 17 0 and 16 0(d,n) 17 F have been studied in the deuteron energy range 4.00 to 6.00 MeV in order to determine to what extent current theories can satisfactorily describe these reactions. The deuteron elastic scattering data were analyzed to obtain optical model parameters suitable for the energy range of the present work. It was found that the theoretical curves from both the optical and DWBA model fit the experimental data significantly better when the deuteron optical model potentials had been obtained using a spin-orbit potential in the analysis of the elastic scattering data. Spectroscopic factors obtained for the ground and first excited states of 17 0 and 17 F using the DWBA theory are in satisfactory agreement with theoretical predictions and with values obtained by previous workers. Small, but nonzero, spectroscopic factors have been calculated for the states at 3.058 and 3.846 MeV excitation in J7 0 using data measured in this work and in previous experiments. The sum of the calculated direct interaction and compound nucleus cross sections is in good agreement with experimental data for all states studied whether they were populated primarily by direct or compound nucleus reactions. The calculated compound nucleus lifetimes are in agreement with values obtained from the analysis of the fluctuations in the yield curves. It was thus found that the combined DWBA and Hauser-Feshbach theories and the optical model give a good description of the energy averaged properties of the 16 0 + d reactions between 4.00 and 6.00 MeV.