Low jitter metal vapor vacuum arc ion source for electron beam ion trap injections

Abstract

We describe a metal vapor vacuum arc (MeVVA) ion source containing eight different cathodes that are individually selectable via the control electronics which does not require moving components in vacuum. Inside the vacuum assembly, the arc plasma is produced by means of a 30μs pulse (26kV,125A) delivering 2.4mC of charge to the cathode sample material. The trigger jitter is minimized (<200ns) to improve the capture efficiency of the ions which are injected into an ion trap. During a single discharge, the over-damped pulse produces an ion flux of 8.4×109ions∕cm2, measured by an unbiased Faraday cup positioned 20cm from the extractor grid, at discharge rates up to 5Hz. The electronic triggering of the discharge is via a fiber optic interface. We present the design, fabrication details, and performance of this MeVVA, recently installed on the National Institute of Standards and Technology electron beam ion trap (EBIT).