Self-field compensation in high-current REB transported by grad-B drift in azimuthal magnetic field

Abstract

AWE has embarked on a programme of work to develop an improved intense electron beam diode for flash x-ray radiography machines. In order to understand the performance of the diode, and to validate computer modeling codes, there is a requirement to obtain time resolved x-ray spot size and position data during the 50 ns electron beam pulse.A simple, low cost, time resolved spot diagnostic is described, based around a number of single frame, fast gating intensified CCD camera modules focussed onto a very fast organic scintillator. Each camera is independently triggered and capable of gate widths down to 2 ns. The complete system is battery driven and controlled remotely via optical fibres to provide electrical isolation and reduce EMP susceptibility.An initial four frame system (easily extendable to 8 frames and beyond) has been developed. Evaluations ofthe optical and radiological response are described. Time resolved spot sire measurements from a number of electron beam diodes fielded upon flash x-ray machines are also reported.