Elucidation of molecular processes in negative ion volume production with measuring VUV emissions in RF discharge D_2 plasmas

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In the design of a neutral beam injection (NBI) system for future large fusion devices such as the ITER, sources of H^- or D^- negative ions are required for generation of efficient neutral beams with energies 1 MeV. Long life time ion sources are also required for the future NBI systems. Microwave discharge plasmas and RF discharge plasmas are promising as long life time ion sources. Here, production and control of D_2 RF discharge plasmas, enhancement of D^- ions production and isotope effect of H^-/D^- production are studied. Findings are summaried as the following five items :1.With magnetic filter method, production and control of DC discharge D_2 plasmas are discussed for enhancement of D^- volume production.2.For enhancement of volume negative ion production, effect of Argon addition into H_2 and D_2 plasmas are discussed with measuring plasma parameters and VUV emissions.3.For H^-/D^- negative ion production, production and control of RF discharge plasmas are studied with grid bias method.4.Grid bias method and magnetic filter method for controlling plasma parameters are discussed for negative ions productions.5.Modeling of negative ion sources.(1)Extraction probability of negative ions in cesium seeded hydrogen plasmas.(2)Relationship between behaviors of primary fast electrons and ionization collisions and excitation collisions of vibrational hydrogen molecules.