CONTENTS I. Elementary Analysis of Radiation of a Charge Moving Along a Helix 34 II. Cerenkov Radiation of a Particle Passing Through a Plate (Layer of Matter) 36 III. Synchrotron Radiation of an Individual Particle Moving at an Arbitrary Angle to the Field 37 IV. Radiation of a System of Particles 38 V. Reabsorption of Radiation of Ultrarelativistic Particles 40 VI. Magnetic-field Variation Connected with Synchrotron Radiation (Losses) Cited Literature 43