Abstract:
An optical detector in a high voltage system senses the blue glow discharge characteristic of insipient failure in rectifier tubes and removes system power. In a preferred embodiment the rectifier tubes are part of a voltage multiplier in a charged particle accelerator and an RF transformer is part of the high voltage supply. Another optical detector is employed to remove power from the accelerator upon sensing blue light in an arc discharge at the RF transformer coil.
Abstract:
A high voltage solid-state rectifier includes multiple series connected ac-compensated diodes and series buffer resistors in a stepped spiral stack. The stack is encased in a sectionalized faraday shield which provides 360* isolation from external rf electrostatic fields and provides external capacitance grading along the stack. Spark gaps between shield sections prevent excessive voltage build-up due to electrical discharges and are arranged in line of sight of each other to permit the ultraviolet light produced from one spark gap firing to stimulate the firing of the other spark gaps. A trigger spark-gap derives its voltage from an inductance in series with the solid-state rectifier. Any electrical discharges which result in an excessive voltage appear initially across the inductance, firing the trigger spark gap which in turn initiates the other spark gaps to fire by ultra-violet stimulation.