Nobel Symposium No. 30 on the Physics of the Hot Plasma in the Magnetosphere was held at Kiruna Geophysical Institute, Kiruna, Sweden from April 2-4, 1975. Some 40 leading experts from America, USSR, and Western Europe attended the Symposium. The purpose of the meeting was to review and discuss the physics of the hot plasma in the magnetosphere with special empha sis on unsolved problems on which attention needs to be focused during the International Magnetospheric Study 1976-1978. The field is very extensive and complete coverage of all aspects was of course not possible. The radiation belts...