Inelastic Scattering And The Distorted Wave Method

Inelastic Scattering and the Distorted Wave Method

An Advanced Course in Modern Nuclear Physics

The ?eld of nuclear physics is entering the 21st century in an interesting and exciting way. On the one hand, it is changing qualitatively since new experim- tal developments allow us to direct radioactive and other exotic probes to target nuclei as well as to sparko? extremely energetic nuclear collisions. In parallel, detector systems are of an impressive sophistication. It is di?cult to envisage all the discoveries that will be made in the near future. On the other hand, the app- cations of nuclear science and technology are broadening the limits in medicine, industry, art, archaeology, and the environmental sciences, etc. This implies that the public perception of our ?eld is changing, smoothly but drastically, in c- trast to former times where nuclear weapons and nuclear power plants were the dominant applications perceived by citizens. Both aspects, scienti?c dynamism and popular recognition, should lead the ?eld to an unexpected revival. One of the consequences of the former could be that many brilliant students consider nuclear physics as an excellent ?eld in which to acquire professional expertise. Therefore, one of the challenges of the international nuclear physics community is to try to make the ?eld attractive. That means simply being pedagogic and enthusiastic. Thus, as organisers of an already established summer school, our contribution was to put an emphasis in this session on pedagogy and enthusiasm.

Coherence and Correlation in Atomic Collisions

H. KLEINPOPPEN AND J. F. WILLIAMS It has only very recently become possible to study angular correlations and coherence effects in different areas of atomic collision processes: These investigations have provided us with an analysis of experimental data in terms of scattering amplitudes and their phases, of target parameters such as orientation, alignment, and state multipoles, and also of coherence parameters (e. g. , the degree of coherence of excita tion). In this way the analysis of electron-photon, ion-photon, atom-photon, or electron-ion coincidences from electron-atom, ion-atom, or atom-atom collisional excitation has led to a breakthrough such that the above quantities represent most crucial and sensitive tests for theories of atomic collision processes. Similarly, the powerful (e, 2e) experiments (electron-electron coincidences from impact ionization of atoms) have attracted much attention where improved experimental studies and detailed theoretical description provide a wealth of information on either the col lisional ionization process or the atomic structure of the target atom. Interference effects, many-electron correlations, and energy and angular momen tum exchange between electrons in a Coulomb field playa decisive role in the under standing of postcollision interactions. New results on coherence effects and orienta tion and alignment in collisional processes of ions with surfaces and crystal lattices show links to relevant interference phenomena in atomic collisions. In small-angle elastic electron-atom scattering the effect of angular coherence can be studied in a crossed beam experiment.