Hybrid Ion Source Development Project at Los Alamos Neutron Science Center

The goal of the of the HYBRid Ion Source (HYBRIS) development project at Los Alamos Neutron Science Center (LANSCE) is to design and test a helicon plasma generator assisted high-current-density H$^{-}$ ion source. The hybrid ion source is a combination of a long-life plasma cathode, sustained by the helicon plasma generator, with a stationary, pulsed main discharge (H$^{-}$ production chamber) directly coupled to each other. The electrons generated in the helicon plasma are transferred to the multi-cusp chamber by ambipolar diffusion igniting the main discharge. The first Langmuir-probe measurement results describing the plasma properties of the helicon discharge will be presented together with the design of the multi-cusp H$^{-}$ production chamber. The strength of the magnetic multi-cusp field confining the plasma in the H$^{-}$ production chamber can be adjusted with the aid of small iron bars. Simulation results illustrating the effect of this special technique on the cusp-field strength will be presented. Also the physical processes affecting the coupling of helicon plasma generator with the primary discharge chamber and the effects of the multi-cusp field strength on plasma confinement will be discussed.