The Conference timetable had to be so arranged as to spread the main topics over several separate sessions. It was therefore decided to publish the material in these Proceedings under nine subject headings, irrespective of session. Within each chapter, which is preceded by a list of the sessions featuring the subject, all papers, invited and contributed, whether presented at the Conference or accepted for publication only, have been arranged in some lo­ gical order. The reports of the four Panel Discussions were edited or summarized by the respective Moderator in consultation with Panel Members. In one instance, shortened versions of the Introductory Papers precede the discussion. Where possible, verbatim accounts of the often lively exchanges have been retained. The customary catalogue of high-energy acceler­ ators has been published separately. The continuing world-wide activities in accelerator research, witl1 its ever larger projects, are reflected by the numerous contributions accepted for inclusion in these Proceedings, which have reached the limit of what a single volume can manageably contain, while making rapid publication even harder to achieve. All the more reason to extend the gratitude of all concerned to those involved in the chain of production: - To the authors, for their prompt handing-in or timely posting of their papers. Thanks also to their secretaries who followed the guidelines for the presentation of camera-ready copy.