First Commissioning Results of the Multicusp Ion Source at MIT (MIST-1) for H${}_2^{+}$

Abstract

IsoDAR is an experiment under development to search for sterile neutrinos using the isotope Decay-At-Rest (DAR) production mechanism, where protons impinging on ${}^9$Be create neutrons which capture on ${}^7$Li which then beta-decays producing $\bar{\hat{I}}{½}_e$. As this will be an isotropic source of $\bar{\hat{I}}{½}_e$, the primary driver current must be large (10 mA cw) for IsoDAR to have sufficient statistics to be conclusive within 5 years of running. H${}_2^{+}$ was chosen as primary ion to overcome some of the space-charge limitations during low energy beam transport and injection into a compact cyclotron. The H${}_2^{+}$ will be stripped into protons before the target. At MIT, a multicusp ion source (MIST-1) was designed and built to produce a high intensity beam with a high H${}_2^{+}$ fraction. MIST-1 is now operational at the Plasma Science and Fusion Center (PSFC) at MIT and under commissioning.