Measurements on a dc volume H− multicusp ion source for TRIUMF

Abstract

We describe a dc volume H− source, employing multicusp plasma confinement, which has been constructed for use with the TRIUMF cyclotron. An extracted H− current density of 12 mA/cm2 has been obtained. Beam emittance and brightness have been measured as a function of current density and beam fraction. Beam brightness values for normalized beam emittances of the order of 0.2 πmm mrad at 81% beam fraction are typically 10 mA/(mm mrad)2 [equivalent rms B=223 mA/(mm mrad)2].