Search Results - "Mitarai, O."

Refueling of field-reversed configuration core via axial plasmoids injection by Asai, T., Takahashi, T., Kobayashi, D., Seki, T., Takeuchi, Y., Mitarai, O., Morelli, J., Mizuguchi, N., Dettrick, S., Gota, H., Roche, T., Matsumoto, T., Binderbauer, M., Tajima, T., Inomoto, M., Takahashi, T.

“…Abstract This study successfully developed a refueling technique for a field-reversed configuration (FRC) via axial plasmoid injection and demonstrated it on…”
Get full text

Demonstration of transient CHI startup using a floating biased electrode configuration by Kuroda, K., Raman, R., Onchi, T., Hasegawa, M., Hanada, K., Ono, M., Nelson, B.A., Rogers, J., Ikezoe, R., Idei, H., Ido, T., Nagata, M., Mitarai, O., Nishino, N., Otsuka, Y., Zhang, Y., Kono, K., Kawasaki, S., Nagata, T., Higashijima, A., Shimabukuro, S., Niiya, I., Sekiya, I., Nakamura, K., Takase, Y., Ejiri, A., Murakami, S.

“…Abstract Results from the successful solenoid-free plasma startup using the method of transient coaxial helicity injection (transient CHI) in the QUEST…”
Get full text

Improvements to the High-Field-Side Transient CHI System on QUEST by Kuroda, K., Raman, R., Hasegawa, M., Onchi, T., Hanada, K., Ono, M., Nelson, B. A., Rogers, J., Ikezoe, R., Idei, H., Ido, T., Mitarai, O., Nagata, M., Kawasaki, S., Nagata, T., Higashijima, A., Shimabukuro, S., Niiya, I., Sekiya, I., Kojima, S., Nakamura, K., Takase, Y., Murakami, S.

“…Transient coaxial helicity injection (CHI) is a promising candidate for solenoid-free plasma current start-up in a low-aspect-ratio tokamak in support of…”
Get full text

Design activities on helical DEMO reactor FFHR-d1 by Sagara, A., Goto, T., Miyazawa, J., Yanagi, N., Tanaka, T., Tamura, H., Sakamoto, R., Tanaka, M., Tsumori, K., Mitarai, O., Imagawa, S., Muroga, T.

“…► Conceptual design studies of the helical DEMO reactor FFHR-d1 have been conducted. ► Design window analyses with core plasma and engineering designs have…”
Get full text

Particle balance in long duration RF driven plasmas on QUEST by Hanada, K., Zushi, H., Yoshida, N., Yugami, N., Honda, T., Hasegawa, M., Mishra, K., Kuzmin, A., Nakamura, K., Fujisawa, A., Idei, H., Nagashima, Y., Watanabe, O., Onchi, T., Watanabe, H., Tokunaga, K., Higashijima, A., Kawasaki, S., Nakashima, H., Takase, Y., Fukuyama, A., Mitarai, O., Peng, Y.K.M.

“…Global particle balance in non-inductive long-duration plasma on QUEST has been investigated. Approximately 70% of the fuel hydrogen (H) was retained in the…”
Get full text

Plasma equilibrium based on EC-driven current profile with toroidal rotation on QUEST by Nakamura, K., Alam, M.M., Jiang, Y.Z., Mitarai, O., Takechi, M., Hasegawa, M., Tokunaga, K., Hanada, K., Idei, H., Nagashima, Y., Onchi, T., Kuroda, K., Watanabe, O., Higashijima, A., Nagata, T., Shimabukuro, S., Kawasaki, S., Fukuyama, A.

“…•Plasma current seems to flow in the open magnetic surface in the outside of the closed magnetic surface in the low-field region.•Considering the toroidal…”
Get full text

Plasma current sustainment after iron core saturation in the STOR-M tokamak by Mitarai, O., Ding, Y., Hubeny, M., Lu, Y., Onchi, T., McColl, D., Xiao, C., Hirose, A.

“…•Plasma current can be started up by small iron core without central solenoid.•Iron core removes central solenoid.•Plasma current can be maintained after iron…”
Get full text

Comparative studies of inner and outer divertor discharges and a fueling study in QUEST by Mitarai, O., Nakamura, K., Hasegawa, M., Onchi, T., Idei, H., Fujisawa, A., Hanada, K., Zushi, H., Higashijima, A., Nakashima, H., Kawasaki, S., Matsuoka, K., Koike, S., Takahashi, T., Tsutsui, H.

“…•Central solenoid has a small flux in QUEST.•Large plasma current is obtained when the position is shifted to the inboard side.•Two types of divertor operation…”
Get full text

Feedback control of the heating power to access the thermally unstable ignition regime in FFHR helical reactor by Mitarai, O., Sagara, A., Sakamoto, R., Yanagi, N., Goto, T.

“…•We discovered feedback control method of heating power in helical reactor.•Thermally unstable high-density ignition regime can be accessed by this…”
Get full text

Plasma equilibrium based on RF-driven current profile without assuming nested magnetic surfaces on QUEST by Nakamura, K., Alam, M.M., Jiang, Y.Z., Mitarai, O., Kurihara, K., Kawamata, Y., Sueoka, M., Takechi, M., Hasegawa, M., Tokunaga, K., Araki, K., Zushi, H., Hanada, K., Fujisawa, A., Idei, H., Nagashima, Y., Kawasaki, S., Nakashima, H., Higashijima, A., Nagata, T., Fukuyama, A.

“…In the present RF-driven (ECCD) steady-state plasma on QUEST, the plasma current seems to flow in the open magnetic surface outside of the closed magnetic…”
Get full text

Optimization activities on design studies of LHD-type reactor FFHR by Sagara, A., Mitarai, O., Tanaka, T., Imagawa, S., Kozaki, Y., Kobayashi, M., Morisaki, T., Watanabe, T., Takahata, K., Tamura, H., Yanagi, N., Nishimura, K., Chikaraishi, H., Yamada, S., Fukada, S., Masuzaki, S., Shishkin, A., Igitkhanov, Y., Goto, T., Ogawa, Y., Muroga, T., Mito, T., Motojima, O.

“…Recent activities on optimizing the base design of the large helical device (LHD)-type helical reactor FFHR (force free helical reactor) are presented. Three…”
Get full text

Heating by an electron Bernstein wave in a spherical tokamak plasma via mode conversion by Shiraiwa, S, Hanada, K, Hasegawa, M, Idei, H, Kasahara, H, Mitarai, O, Nakamura, K, Nishino, N, Nozato, H, Sakamoto, M, Sasaki, K, Sato, K, Takase, Y, Yamada, T, Zushi, H

“…The first successful high power heating of a high dielectric constant spherical tokamak plasma by an electron Bernstein wave (EBW) is reported. An EBW was…”
Get full text

Development of plasma control system for divertor configuration on QUEST by Hasegawa, M., Nakamura, K., Zushi, H., Hanada, K., Fujisawa, A., Matsuoka, K., Mitarai, O., Idei, H., Nagashima, Y., Tokunaga, K., Kawasaki, S., Nakashima, H., Higashijima, A.

“…A plasma control system to sustain divertor configurations is developed on QUEST (Q-shu university experiment with steady-state spherical tokamak). Magnetic…”
Get full text

Formation of advanced tokamak plasmas without the use of an ohmic-heating solenoid by Shiraiwa, S, Ide, S, Itoh, S, Mitarai, O, Naito, O, Ozeki, T, Sakamoto, Y, Suzuki, T, Takase, Y, Tanaka, S, Taniguchi, T, Aramasu, M, Fujita, T, Fukuda, T, Gao, X, Gryaznevich, M, Hanada, K, Jotaki, E, Kamada, Y, Maekawa, T, Miura, Y, Nakamura, K, Nishi, T, Tanaka, H, Ushigusa, K

“…A new operational scenario of advanced tokamak formation was demonstrated in the JT-60U tokamak. This was accomplished by electron cyclotron and lower hybrid…”
Get full text

Conceptual design activities and key issues on LHD-type reactor FFHR by Sagara, A., Mitarai, O., Imagawa, S., Morisaki, T., Tanaka, T., Mizuguchi, N., Dolan, T., Miyazawa, J., Takahata, K., Chikaraishi, H., Yamada, S., Seo, K., Sakamoto, R., Masuzaki, S., Muroga, T., Yamada, H., Fukada, S., Hashizume, H., Yamazaki, K., Mito, T., Kaneko, O., Mutoh, T., Ohyabu, N., Noda, N., Komori, A., Sudo, S., Motojima, O.

“…An overview of conceptual design activities on the LHD-type helical reactor FFHR is presented, mainly focusing on optimization studies on the reactor size and…”
Get full text

Eddy current-adjusted plasma shape reconstruction by Cauchy condition surface method on QUEST by Nakamura, K., Jiang, Y., Liu, X.L., Mitarai, O., Kurihara, K., Kawamata, Y., Sueoka, M., Hasegawa, M., Tokunaga, K., Zushi, H., Hanada, K., Fujisawa, A., Sakamoto, M., Idei, H., Kawasaki, S., Nakashima, H., Higashijima, A., Araki, K.

“…CCS (Cauchy Condition Surface) method is a numerical approach to reproduce plasma shape, which has good precision in conventional tokamaks. In order to apply…”
Get full text

Aspect ratio dependencies of D– 3He fueled tokamak reactors by Mitarai, O., Matsuura, H., Tomita, Y.

“…Ignition capability is studied and compared for two types of D– 3He spherical tokamak (ST) and medium aspect ratio tokamak (MT) reactors. The required power…”
Get full text

Progress of design studies on an LHD-type steady state reactor by Motojima, O., Komori, A., Sagara, A., Yamada, H., Mitarai, O., Sakamoto, R., Miyazawa, J., Kobayashi, M., Morisaki, T., Masuzaki, S., Imagawa, S., Kozaki, Y., Tanaka, T.

“…Progress of design studies on a heliotron reactor is reported. Recent experimental achievements in large helical device (LHD) are building up the physical…”
Get full text

Pellet injection algorithm for the FFHR helical reactor by Mitarai, O., Oda, A., Sagara, A., Yamazaki, K., Motojima, O.

“…Pellet injection algorithm has been proposed for engineering developments in the force free helical reactor (FFHR) based on the zero-dimensional equations. In…”
Get full text

Carbon tiles as spectral-shifter for long-life liquid blanket in LHD-type reactor FFHR by Sagara, A., Imagawa, S., Tanaka, T., Muroga, T., Kubota, Y., Dolan, T., Hashizume, H., Kunugi, T., Fukada, S., Shimizu, A., Terai, T., Mitarai, O.

“…In terms of engineering feasibility for long-life Flibe blanket in LHD-type reactor FFHR, the Spectral-shifter and Tritium breeder Blanket (STB) concept is…”
Get full text