Recent Results of High Density Experiments in the Gamma 10 Tandem Mirror

• DOI: 10.13182/fst03-a11963580
• Publication Date: 2018-04-27T09:27:01Z
• Authors: Y. Nakashima; T. Cho; T. Fukasawa; H. Higaki; M. Hirata; H. Hojo; M. Ichimura; K. Ishii; Y. Ishimoto; M. K. Islam; A. Itakura; T. Ito; I. Katanuma; S. Kobayashi; J. Kohagura; Y. Kubota; R. Minami; T. Numakura; T. Saito; B. S. Saosaki; Y. Takemura; Y. Tatematsu; M. Yoshida; M. Yoshikawa; K. Yatsu
• Keywords: 0103 physical sciences; 01 natural sciences; 7. Clean energy

High-density experiments using newly applied ion-cyclotron range of frequency (ICRF) wave and neutral beam injection (NBI) in the GAMMA 10 tandem mirror are described. A new ICRF wave system (RF3) with high harmonic frequency has been introduced for achieving high density. In addition, neutral beam injectors were recently installed at the central and anchor cells for fueling to target plasmas produced by ICRF waves. Arrays of Ha line-emission detectors are installed from the midplane of the central-cell to the anchor-cell in order to evaluate the particle source density around these regions. In a typical ICRF-heated hot-ion-mode plasma, both anchor and central NB's are injected together with the RF3 wave and the significant increase of the line-density in the central-cell up to ∼8x10 12 cm -2 was attained during the potential formation. It is confirmed that this high density is achieved under the ion temperature of three times higher than the value expected from the usual empirical boundary without using these new heating systems. An analysis of neutral particle transport using the Monte Carlo simulation code is developed to calculate the spatial profile of neutral density in non-axisymmetric region, such as anchor cell. Particle source rate is estimated based on detailed measurements of Ha line-emission from the central-cell to the east anchor-cell together with the neutral transport simulation.