Explosive developments in microelectronics, interest in nuclear metallurgy, and widespread applications in surface science have all produced many advances in the field of ion implantation. The research activity has become so intensive and so broad that the field has become divided into many specialized subfields. An Advanced Study Institute, covering the basic and common phenomena of aggregation, seems opportune for initiating interested scientists and engineers into these various active subfields since aggregation usually follows ion implantation. As a consequence, Drs. Perez, Coussement, Marest, Cachard and I submitted such a pro posal to the Scientific Affairs Division of NATO, the approval of which resulted in the present volume. For the physicist studying nuclear hyperfine interactions, the consequences of aggregation of implanted atoms, even at low doses, need to be taken into account if the results are to be correctly interpreted. For materials scientists and device engineers, under standing aggregation mechanisms and methods of control is clearly essential in the tailoring of the end products.

Inhalt
General Introduction.- I Basic Notions on Implantation.- Basic Implantation Processes.- Ion Implantation Procedure.- Radiation Damage as Probed by Impurities.- II Characterization by Nuclear Methods of Isolated Implanted Atom Sites.- Magnetic Hyperfine Interactions in Implanted Systems.- Quadrupole Interaction.- Isomer Shift and Recoilless Fraction.- Time Dependent Hyperfine Interactions.- Directional Distribution of Nuclear Gamma Radiation.- Nuclear Orientation.- NMR Detected by Nuclear Radiation: NMR/ON.- Mössbauer Spectroscopy.- Perturbed Angular Correlation.- Atom Site Characterization in Metals Using Channeling Techniques.- III Implantation Effects at Higher Concentrations, Aggregation Phenomena.- Radiation Effects in Metals.- Precipitation Processes in Implanted Materials.- Equilibrium Phase Formation by Ion Implantation.- Formation of Nonequilibrium Systems by Ion Implantation.- Perturbations of the Sputtering Yield.- IV Applicability of Solid State and Nuclear Methods.- to Some Solid State Methods for the Study of Isolated Implanted Atom Sites in Metals.- An Introduction to Several Solid State Techniques for the Study of Ion Implanted Materials.- Nuclear Methods for Studying Aggregation Problems.- Comparison Between Nuclear Physics Methods and Solid State Physics Methods for the Study of Implanted Atoms Sites in Metals: Solid State Methods.- Comparison of Nuclear Methods with Solid State Methods: Nuclear Methods.- V New Fields of Applications.- Surface Property Modification in Ion-Implanted Metals.- Implantation in Optical Materials.- A General Survey of the Panel Discussions.- Concluding Remarks.- Participants.