The observed disruption of intense runaway electron streams in a plasma betatron

Abstract

This thesis describes an investigation of the problem of producing an intense stream of runaway electrons. With an argon plasma (density from 4 x 1010 to 4 x 1011 cm-3) in an azimuthal magnetic field of 0.1 webers/m2, accelerating fields from 8.8 x 102 to 8.8 x 103 volts/m were used. Refined Rogowski-coil and scintillationdetector diagnostic techniques were used to study the behavior of the system. Intense runaway electron streams were observed. Disruption of the stream occurred approximately 0.4 usec after its formation. X radiation was observed during the disruption. The energy of the electrons producing the x rays (approximately 100 kev), is less than would have been observed if they were accelerated freely from the moment of application of the accelerating field. It is concluded that the disruption of the streaming motion is due to an instability.