A high current, high brightness, 10 pulsor per second (pps) ion source is a key component of a heavy ion fusion accelerator. This project will use a high purity, pulsed inductive, gas-breakdown plasma source to generate a plasma with a high directed velocity. The source is positioned a large distance from the accelerator, resulting in separation of neutral gas from the accelerator and collimation of the ions entering the accelerator. The goal of Phase I and II is to develop and field an ion source on the first stage of an accelerator. Phase I developed a configuration for an inductively driven gas-breakdown plasma source that produced a >10 ms pulse of Argon plasma of >100mA/cm2 ion current density, with strongly axially directed ion energy of about 80 eV, and sub-eV transverse temperature. The plasma was highly reproducible in spatial, temporal, and energy distributions. Phase II will explore techniques to control the temporal shape of the ion pulse and improve the spatial uniformity. More detailed measurements of the source, both at the gas breakdown region and downstream, will be performed to enhance the understanding of source behavior. A 100 keV acceleration stage will be developed and used with the ion source to precisely quantify source performance, especially the transverse and longitudinal ion temperatures, and to explore effects of changes in source characteristics on beam quality.
Commercial Applications and Other Benefits as described by the awardee: Commercial applications of pulsed inductive plasma sources include plasma and ion beam processing and plasma propulsion schemes. Ion sources should also have applications to other fusion power approaches, including high flux neutral beams and plasmoids for injection into magnetically confined plasmas and field reversed ion rings.
