Detection of x rays from the anode of a vacuum arc

Abstract

A vacuum arc with hollow cylindrical anode can generate an arc voltage in excess of 10 000 V with currents in excess of 1000 A. A model has been developed that describes this high arc voltage as being caused by the conduction of the current through an electron space-charge region near the anode. The detection of x rays emitted from the anode at the time of the high arc voltage has confirmed the model of this vacuum arc. An x-ray pinhole camera gave spatial resolution and showed that the x rays were emitted from the anode. A p-i-n diode x-ray detector gave temporal resolution and showed that the x rays were emitted during the high arc voltage mode. A lithium fluoride crystal spectrometer gave energy resolution and showed that the emitted x rays were characteristic of the copper anode. This experiment confirmed that the major energy dissipation mechanism for this arc during the high voltage mode was the bombardment of the anode by electrons.