Influence of gas flow on argon microwave plasma jet at atmospheric pressure

Many kinds of an atmospheric-pressure plasma jet have been developed and used for widespread applications such as a surface treatment and modified. This study focused on the argon atmospheric-pressure m jet generated by discharging of RF power of 2.45 GHz microwave. The plasma jet shows sensitivity to surrounding environment: pressure, temperature and gaseous species. It is therefore absolutely imperative that a nature of atmospheric-pressure plasma jet should be understood from a point of fluid dynamics. This study, therefore, focused on the interrelationship between the plasma jet and the working gas. Motion of the plasma jet and the working gas was evaluated by velocity measurement and fast photography. As a result, the unsteady sinusoidal waving motion in the radial direction of a torch was observed. Advection velocity of the plasma in just downstream region of the torch exit increases with the supplying flow rate, and the velocity ratio is in the range of 0.75-0.87.ArticleSURFACE & COATINGS TECHNOLOGY. 206(6):1449-1453 (2011)journal articl

Sensitivity Improvement of Infrared Imaging Video Bolometer for Divertor Plasma Measurement

The sensitivity of an infrared imaging video bolometer (IRVB) was improved for the measurement of relatively low energy plasma radiation from the viewpoint of the metal foil absorber material. The photon energy of the radiation was considered up to 1 keV for the divertor plasma measurement. The thickness of the foil absorber was evaluated not only for conventional heavy elements, e.g., platinum, but also for light elements by the relation between the photon energy and attenuation length and by mechanical strength. A heat-transfer calculation using ANSYS suggested that light elements with practical foil thickness provide a higher temperature rise of the foil absorber compared with heavier elements with practical foil thickness. The maximum of the temperature rise was evaluated using He–Ne laser irradiation onto absorber samples. The material dependence of the temperature rise has a similar tendency between calculations and experiments. Experimentally, the sensitivity of the IRVB improved from 280 to 110 µW/cm2 using titanium with 1 µm thickness compared with conventional platinum with 2.5 µm thickness. Consequently, the signal-to-noise ratio of the IRVB could be improved from 2.8 to 9.1

境界領域模擬プラズマにおけるイオン温度の精密測定

科学研究費助成事業 研究成果報告書：基盤研究(C)2013-2015課題番号 : 2542088

複合ガス入射による非接触プラズマ挙動の理解と制御

科学研究費助成事業 研究成果報告書：基盤研究(C)2019-2021課題番号 : 19K0379

Structures of Detached Plasmas with High Heat Flow in a Strong Magnetic Field

書誌情報のみBibliographic data Onl

Benchmarking of B2 Code with a One-Dimensional Plasma Fluid Model Incorporating Anisotropic Ion Pressures on Simple Mirror Configurations

A plasma fluid code B2 has been benchmarked with a one-dimensional plasma fluid model incorporating the anisotropic ion pressures (AIP model) on simple mirror configurations. In a low collisionality case, profiles of plasma parameters of the B2 code deviate from those of the AIP model. The validity of the viscous-flux approximation is investigated by direct comparisons with the anisotropic part of the ion pressure indicating the invalidity of the viscous-flux approximation is considered to be responsible to deviations of profiles. In addition, supersonic plasma flows downstream from the mirror throat are observed