Bibliothèque de L'IMIST/CNRST

WKB-Approximation in Quantum Mechanics -- One-Dimensional Motion -- WKB-Approximation for a Particle in Central Field -- Langer Transformation -- 1/N-Expansion in Quantum Mechanics -- 1/N Expansion for Energy Levels of Binding States -- Wave Functions of 1/n-Expansion -- Rydberg States of Atomic Systems -- Unperturbed Rydberg States of Atoms -- Interaction between a Rydberg Electron and an Electromagnetic Radiation -- Penetrability of Potential Barriers and Quasistationary States -- Quasi-Stationary States of One-Dimensional Systems -- Quasi-Stationary States and Above-Barrier Reflection -- Transitions and Ionization in Quantum Systems -- Adiabatic Transitions -- Ionization of Quantum Systems.

This book has evolved from lectures devoted to applications of the Wentzel - Kramers – Brillouin- (WKB or quasi-classical) approximation and of the method of 1/N −expansion for solving various problems in atomic  and nuclear physics. The intent of this book is to help students and investigators in this field to extend their knowledge of these important calculation methods in quantum mechanics. Much material is contained herein that is not to be found elsewhere. WKB approximation, while constituting a fundamental area in atomic physics, has not been the focus of many books. A novel method has been adopted for the presentation of the subject matter, the material is presented as a succession of problems, followed by a detailed way of solving them. The methods introduced are then used to calculate Rydberg states in atomic systems and to evaluate potential barriers and quasistationary states. Finally, adiabatic transition and ionization of quantum systems are covered.