GB710421A - Improvements relating to magnetic induction accelerators - Google Patents

Abstract

710,421. Magnetic induction accelerators. METROPOLITAN - VICKERS ELECTRICAL CO., Ltd. Aug. 9, 1951 [Aug. 29, 1950], No. 18788/51. Class 39(1) A betatron in which the faces of the pole pieces 2, 3 on each side of the annular gap which includes the orbital path are chamfered or graded in such manner that the length of the gap increases progressively with increase of radius from the axis of the betatron (except in the outermost regions), is provided with a set of electrically separate compensating coils 31 which extend circumferentially of the betatron along the surfaces 4, 5 of the annular pole pieces, and are adapted to correct radial flux distribution when appropriately excited, so as to stabilize the electron movement in the desired orbital path. Imperfections in the radial flux distribution may arise due to irregularities in the magnetic structure and by means of the compensating coils the magnetic field may be made to conform to the relationship H # <SP>1</SP>/r<SP>n</SP> (o>n<1). Also, the magnetic lines of force may be made perpendicular to the plane of symmetry of the annular container 6. Each compensating coil is in series with a variable resistance. The energizing currents for the coils may be alternating or direct. The alternating currents may be simply those induced by the betatron acceleration field. The coils may also be excited from an A.C. source synchronized with the betatron acceleration field. With direct current induced alternating currents are suppressed.