Production of High Lo Surdo Fields

Abstract

IT has already been reported in this journal (NATURE, Aug. 25, 1928, p. 277) by one of us, that the field strength in a Lo Surdo tube may be increased considerably by the simple device of using proper periodic impulses as the terminal supply. Since then the experimental arrangement has been improved so that a steady discharge may be maintained in a capillary tube the inner diameter of which is as small as 0.5 mm. for two or three hours. First, the volume of the discharge tube was increased to more than 20 litres; and secondly, only the half wave was used by taking off some of the vanes of the synchronous motor rectifier. Finally, the induction was removed from the secondary circuit. In this way the maximum voltage attained was roughly 1.2 million volts per cm.