Accès ouvert
2026
article
OpenAlex
Masayuki Yoshikawa, Kazuma Yoshida, Junko KOHAGURA, Naomichi Ezumi et autres
The transient detachment dynamics under upstream perturbations was investigated in the GAMMA 10/PDX tandem mirror device using a combination of supersonic molecular beam injection (SMBI) and radio-frequency heating. These actuators generated intermittent high-density plasma fluxes directed toward the divertor-simulation module, enabling controlled …
jp, nl
(code pays fourni par la source)
Accès ouvert
2026
article
OpenAlex
Tomoharu Numakura, M. Sakamoto, Naomichi Ezumi, Masayuki Yoshikawa et autres
In toroidal confinement systems, the scrape-off layer (SOL) magnetic field exhibits characteristics analogous to those of a magnetic mirror configuration, particularly in the edge plasma region. Therefore, linear plasma devices have advanced divertor simulation studies. To further promote divertor simulation studies, a …
jp
(code pays fourni par la source)
Accès ouvert
2026
article
OpenAlex
R. Ikezoe, Wooran Fumikawa, T. Onchi, Kazuaki HANADA et autres
Abstract Radio-frequency (RF) modification of edge plasma transport provides a potential pathway for active control of particle and heat fluxes in magnetically confined plasmas. In this study, we experimentally demonstrate RF-induced transport modification in a toroidal open-field-line plasma produced in QUEST, using …
jp
(code pays fourni par la source)
Accès ouvert
2026
article
OpenAlex
Masayuki Yoshikawa, Junko KOHAGURA, Naomichi Ezumi, T. Kariya et autres
Abstract Detached plasma dynamics under transient upstream perturbations were investigated in the divertor simulation module of GAMMA 10/PDX using double-pulse central electron cyclotron heating (C-ECH) to generate controlled transient heat and particle fluxes. Detached plasma was produced by radiator gas injection, and …
jp, us, nl
(code pays fourni par la source)
Accès ouvert
2025
article
OpenAlex
Yuta Kinashi, Naomichi Ezumi, Takumi SETO, Reina Miyauchi et autres
Abstract High-density and large-diameter plasma generation is expected to contribute to semiconductor manufacturing, space propulsion, and nuclear fusion. We develop a plasma generation method for high-density, large-diameter plasma by combining the advantages of both hot cathode arc discharge and helicon wave discharge …
jp
(code pays fourni par la source)
Accès ouvert
2024
article
OpenAlex
Masayuki Yoshikawa, Junko KOHAGURA, Naomichi Ezumi, T. Kariya et autres
Plasma detachment is one of the most significant factors affecting nuclear fusion reactors. GAMMA 10/PDX has a divertor simulation experimental module (D-module) for detached plasma studies in the end region. To investigate the effect of suddenly changing the higher-density particle flux into …
jp, us, nl
(code pays fourni par la source)
2024
article
OpenAlex
Takumi SETO, Naomichi Ezumi, Reina Miyauchi, Takuma Okamoto et autres
New plasma applications in advanced fields, such as fundamental nuclear fusion research, require high-density, large-diameter plasma with a strong and non-uniform magnetic field. A helicon plasma (HP) source using a flat-type antenna is expected to be one of the promising methods for …
jp
(code pays fourni par la source)
Accès ouvert
2023
article
OpenAlex
Yudai SUGIMOTO, M. Hirata, Yousuke NAKASHIMA, Makoto Ichimura et autres
One of the greatest challenges of simulating the high heat flux on the divertor in linear plasma devices is the achievement of ion temperatures of > 100 eV under high densities (≥1019 m−3). The slow wave in the ion cyclotron range of …
jp, ru
(code pays fourni par la source)
Accès ouvert
2023
article
OpenAlex
Kosuke Takanashi, S. Togo, Naomichi Ezumi, M. Hirata et autres
We investigated the contribution of magnetic moment conservation to ion energy transport in the divergent magnetic field region, using the GAMMA 10/PDX end region to simulate scrape-offlayer (SOL) plasmas in DEMO reactors. The averaged parallel energy increments (∆E∥) were measured by performing …
jp, ru
(code pays fourni par la source)
Accès ouvert
2023
article
OpenAlex
Takumi SETO, Naomichi Ezumi, Reina Miyauchi, Naoki SHIGEMATSU et autres
To study DEMO divertors, some linear devices have attempted to create DEMO-grade high-density steady-state divertor simulation plasma in a stronger magnetic field. Helicon plasma sources using a flat-type antenna, which are one of the methods of radio frequency (RF) plasma generation in …
jp, ru
(code pays fourni par la source)
Accès ouvert
2023
article
OpenAlex
Naoki SHIGEMATSU, Naomichi Ezumi, K. Mukai, Takumi SETO et autres
Plasma radiation intensity distribution plays a crucial role in the energy balance and impurity transport during plasma detachment. An InfraRed imaging Video Bolometer (IRVB) is a radiation distribution measurement system, that uses an infrared camera to measure the temperature distribution on a …
jp, ru
(code pays fourni par la source)
Accès ouvert
2023
article
OpenAlex
Doyeon Kim, M. Hirata, Yudai SUGIMOTO, Takaaki KOZAWA et autres
In GAMMA 10/PDX, ion heating is achieved using slow wave in the ion cyclotron frequency absorbed near the resonance layer. However, in high-density plasma, the slow wave is less likely to be excited due to the shielding effect. To overcome this challenge, …
jp, ru
(code pays fourni par la source)