The NATO Advanced Study Institute on "Atomic and Molecular Processes in Controlled TheI'IllOnuclear Fusion" was held at Chateau de Bonas, Castera-Verduzan, Gel's, France, from 13th to 24th August 1979, and this volume contains the text of the invited lectures. The Institute was supported by the Scientific Affairs Division of NATO, and additional support was received from EURATOM and the United States National Science Foundation. The Institute was attended by 88 scientists, all of whom were active research workers in control of thermonuclear plasmas, 01' atomic and molecular physics, 01' both. In addition to the formal lectures, printed in this volume, which were intended to be pedagogic, more than twenty research seminars were given by participants. The first half of the Institute was directed to introducing atomic and molecular theoretical and experimental physicists to the physics of controlled thermonuclear fusion. Most attention was paid to magnetic confinement, and within that field, to tokamaks. MI'.