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.

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 development of mineralogy, the evolutionary changes in compre hending the mineral substance of the earth are closely associated with the progress of research methods. Over a space of more than two and half centuries, from the goniometry of the mineral crystals to microscopic petrography and optical mineralogy, to crystal structure determinations, electron micros copy and electron diffraction and finally investigations into their electri cal, magnetic and mechanical properties, all this has led to the formation of the existing system of mineralogy, its notions, theories and to a proper description of minerals. However, no matter how great the variety of methods employed in mineralogy, they all come to a few aspects of substance characteristics. These are methods of determining the composition, structure and proper ties of the minerals. Thus the X-ray micro analyzer, the atom-absorption, neutron-activation, chromatographic and other analyses open up new opportunities for determining nothing else but the elementary com position of minerals.

Luminescence of Solids gathers together much of the latest work on luminescent inorganic materials and new physical phenomena. The volume includes chapters covering -- the achievements that have led to the establishment of the fundamental laws of luminescence -- light sources, light-dispersing elements, detectors, and other experimental techniques -- models and mechanisms -- materials preparation, and -- future trends. This international collection of cutting-edge luminescence research is complemented by over 170 illustrations that bring to life the text's many vital concepts.