These Proceedings report the scholarly work presented in Leningrad at the largest conference ever held on luminescence. In addition to the large number of delegates, the Conference was dis tinguished by strong and balanced representation on the program of papers from capitalist and socialist nations. The Conference was sponsored by the International Union of Pure and Applied Physics and by the Academy of Science of the USSR. As noted in the Opening Ceremony, this Conference is in the series held approximately every three years since 1938. All branches of luminescence are included. It was recognized, during the early stages of organization of the Conference, that there would be difficulties associated with the preparation of an English version of the Proceedings. Until just before the Conference, it was not evident whether translations of the Russian papers would be available and whether facilities would exist at the Conference for a working publication committee to edit the manuscripts. It was not possible, therefore, to make contractual arrangements before the Conference for publication.

The author attempts to present in a condensed form the fundamentals of the physics of luminescence. He presents his own views on the subject. The book is divided into the following main sections:

These Proceedings report the scholarly work presented in Leningrad at the largest conference ever held on luminescence. In addition to the large number of delegates, the Conference was dis tinguished by strong and balanced representation on the program of papers from capitalist and socialist nations. The Conference was sponsored by the International Union of Pure and Applied Physics and by the Academy of Science of the USSR. As noted in the Opening Ceremony, this Conference is in the series held approximately every three years since 1938. All branches of luminescence are included. It was recognized, during the early stages of organization of the Conference, that there would be difficulties associated with the preparation of an English version of the Proceedings. Until just before the Conference, it was not evident whether translations of the Russian papers would be available and whether facilities would exist at the Conference for a working publication committee to edit the manuscripts. It was not possible, therefore, to make contractual arrangements before the Conference for publication.

This collection of papers describes investigations of luminescence centers in II-VI crystal phosphors, ruby, and molecular crystals. These investigations were carried out using spectroscopy in a wide range of wavelengths, electron paramagnetic resonance, and polarization methods. The relationship between the thermal and optical depths of electron traps is considered specifically. The articles in this collection should be of interest to all scientists investigating the luminescence of solids.