Increasing electric standoff between conductors in vacuum

Pulsed power systems have limitations on power delivery. One limitation is the breakdown potential between conductive surfaces in vacuum. In a vacuum breakdown, a vacuum arc is generated between the surfaces. The microscopic limit on the breakdown potential is at the onset of field emission from the surface. The microscopic field for the onset of field emission is in excess of 1e9 V/m. Typical macroscopic breakdown fields between conductors vacuum are often less than 1e7 V/m. We have developed techniques to design and condition surfaces to withstand 5 to 10 times this electric field. We describe the conditioning technique and explore improved manufacturing techniques to increase the operating electrical potential of systems. DC applications include high voltage ion implanters, miniature X-ray tubes and fast, high level X-ray diodes used to diagnose fusion systems. Pulsed power applications could be developing very high power miniature, sealed; flash x-ray systems and compact CW pulsed power accelerators