| Abstract: | This article is devoted to the design of a cyclotron with a spatially varying magnetic field. The basic conclusions of the linear theory of motion of charged particles in a magnetic field of periodic radial and azimuthal structure are given. The theoretical and experimental results of the study of nonlinear resonance close to the center of the accelerator are presented. Formulas are obtained for the calculation of required magnetic field configurations. Methods of shimming, measurement, and stabilization of the magnetic field are suggested. An accelerator designed with pole faces of diameter 120 cm was used for modeling the ion phase motion and for investigating spatial stability. Deuterons were accelerated to an energy of 13 Mev at an accelerating voltage of 5 kv.A brief account of the starting up of this accelerator appeared in the journal Atomnaya Energiya6, 6, 657 (1959). Original Russian pagination. See. C. B. translation]The authors highly appreciate the great amount of work and effort on the part of the personnel of the experimental shop, designing office, electronic and electrical departments of the Nuclear Problems Laboratory of the Joint Institute of Nuclear Studies. The authors are deeply grateful to these personnel and to their chiefs K. A. Baicher, N. I. Frolov, M. F. Shul'ga, F. V. Chumakov for their aid, valuable discussions, and suggestions in solving many technical problems. The authors express their gratitude to D. I. Blokhintsev, D. V. Efremov, K. N. Meshcheryakov, V. N. Sergienko for constant interest and assistance, which greatly facilitated the work, to E. G. Komar, I. F. Malyshev, L. N. Fedulov for constructing and preparing the chamber and the magnet of the accelerator, to A. V. Chestnyi for help during the first stage of setting up the technical problem. |
