GB725358A - Improvements in or relating to circuits for producing expansion and contraction of the circular electron orbit in a magnetic induction accelerator - Google Patents

Abstract

725,358. Magnetic induction accelerators. BROWN, BOVERI & CO., Ltd. April 2, 1953 [April 3, 1952], No. 9216/53. Class 39 (1). A circuit for producing orbit expansion and contraction pulses as desired in a betatron having a main excitation winding 1, and a coil 2 surrounding the accelerating flux, consists of two thyratrons 6, 7 connected in parallel with opposite polarity. Positive voltage pulses are applied alternately to the control grids of the thyratrons when the supply voltage passes through zero. A capacitor 4 is connected in series with both thyratrons, and a change-over switch 9 connects in one position e, the capacitor and the thyratrons with the coil 2, and in the other position k with the coil 2 and main excitation winding 1 arranged in series. This series arrangement is such that the voltages on the coil and main excitation winding oppose each other. The switch 9 is in position e for expansion and in position k for contraction. The expansion and contraction pulses are produced by charging the capacitor 4, the voltage source being the alternating voltage induced in the coil 2 in the case of expansion, and the difference between the supply voltage and the induced voltage in the case of contraction. The coil 2 is preferably so dimensioned that the pulses for contraction and expansion have equal amplitude, but by suitably dimensioning the coil, the pulses may be of different amplitude. The positive voltage pulses for the control grids of the thyratrons may be obtained by the conversion of the sinusoidal voltage taken from the supply system, as by a device 8. A switch 10 for reversing the phase is located between the supply system and the device 8, and is actuated simultaneously with the switch 9. Alternatively, the sinusoidal voltage may be taken from the series-connected capacitor and thyratrons. The betatron may be of the type in which the electrons are alternately accelerated in opposite directions. Specification 656,627 is referred to.