A5002952735- Magnetic confinement fusion research
- Plasma Diagnostics and Applications
- Ionosphere and magnetosphere dynamics
- Particle accelerators and beam dynamics
- Solar and Space Plasma Dynamics
- Laser-Plasma Interactions and Diagnostics
- Superconducting Materials and Applications
- Fusion materials and technologies
- Laser-induced spectroscopy and plasma
- Metal and Thin Film Mechanics
- Geomagnetism and Paleomagnetism Studies
- Atomic and Subatomic Physics Research
- Advanced Combustion Engine Technologies
- Dust and Plasma Wave Phenomena
- Catalytic Processes in Materials Science
- Nuclear Physics and Applications
- Magnetic Field Sensors Techniques
- Electrostatic Discharge in Electronics
- Ion-surface interactions and analysis
- Laser Design and Applications
- Advanced MRI Techniques and Applications
- Medical Imaging Techniques and Applications
- Nuclear Materials and Properties
- Plasma Applications and Diagnostics
- Electromagnetic Launch and Propulsion Technology
Nihon University
2016-2025
Surugadai Nihon University Hospital
2007-2013
Suwa Red Cross Hospital
2011
Nagaoka University of Technology
2008-2009
National Institute of Advanced Industrial Science and Technology
2003-2004
University of Saskatchewan
2003
Osaka University
2000-2003
Tokyo Medical and Dental University
2001-2002
Tohoku Medical and Pharmaceutical University
1999
Background.In chronic kidney disease stage 5D, diagnostic usefulness of bone mineral density (BMD) in predicting fracture has not been established because variable results previous studies. The reason for this may be the heterogeneity underlying pathogenesis fracture.
TAE Technologies' research is devoted to producing high temperature, stable, long-lived field-reversed configuration (FRC) plasmas by neutral-beam injection (NBI) and edge biasing/control. The newly constructed C-2W experimental device (also called 'Norman') the world's largest compact-toroid (CT) device, which has several key upgrades from preceding C-2U such as higher input power longer pulse duration of NBI system well installation inner divertors with upgraded electrode biasing systems....
Tri Alpha Energy's experimental program has demonstrated reliable field-reversed configuration (FRC) formation and sustainment, driven by fast ions via high-power neutral-beam (NB) injection. The world's largest compact-toroid device, C-2U, was upgraded from C-2 with the following key system upgrades: increased total NB input power ~4 MW (20 keV hydrogen) to 10+ (15 tilted injection angle; enhanced edge-biasing capability inside of each end divertor for boundary/stability control. C-2U...
// Kosuke Saito 1, 2 , Tomohiko Asai 3 Kyoko Fujiwara Junki Sahara Haruhisa Koguchi 4 Noboru Fukuda 5 Miki Suzuki-Karasaki 6 Masayoshi Soma Yoshihiro 7 1 Innovative Therapy Research Group, Nihon University Institute of Medical Science, Tokyo, Japan Division General Medicine, Department School Physics, College Science and Technology, University, The National Advanced Industrial Tsukuba, Nephrology Hypertension Endocrinology, Dermatology, Surugadai Hospital, Saitama, Physiology, Biomedical...
The field-reversed configuration (FRC) amplification via a translation–collisional merging device was used to conduct experiments where two initial FRC-like plasmoids produced by the theta pinch method were translated and accelerated supersonic/Alfvénic velocities before being subjected collisional merging. temporal evolution of toroidal flow measured throughout each experimental phase. initially rotated in ion paramagnetic direction relative open-field region subsequently spun up...
Abstract In this paper, we use hybrid simulation to elucidate the plasma heating mechanism due waves excited in Field-Reversed Configuration plasma(FRC). The parameters are a separatrix radius of 0.16 m and length 1.16 (x-point position is z = ±0.57 m). wave excitation antenna consists two loop antennas with 0.3 placed at ±0.5 m. current waveform sine maximum value 30 kA frequency 160 kHz. results showed that caused compression/expansion plasma, same time, temperature increased or decreased...
Recently, many plastic products have been produced and used. These are mostly manufactured using injection molding machines. The quality of depends on the force. Therefore, it is important to develop a fine force-control system. Generally, in systems, force information from environment detected by sensor. However, control systems sensors present problems related signal noise, sensor cost, narrow bandwidth, other factors. To overcome these problems, this paper presents proposal for new...
Collisional merging formation of field-reversed configurations (FRCs) at super Alfvenic velocity have been successfully initiated in the FAT-CM device Nihon University. It is experimentally evidenced that quiescent FRC profile formed a self-organizational manner after distructive disturbances by collision two translated magnetized plasmoids. A drastic increase excluded flux compared to theta-pinch section has also observed. This process an important role realizing based high-beta reactor...
The super-Alfvénic acceleration of an extremely high beta plasmoid due to a magnetic pressure gradient is evidenced in translation experiments involving the field-reversed configuration (FRC) FRC amplification via translation-collisional merging (FAT-CM) device. Inside FRC, there population unmagnetized particles that forms volume with beta. Formed using theta pinch method, accelerated and injected into quasi-static confinement field weaker than formation fields. Because nonzero axial speed...
Abstract Self-organized field-reversed configuration (FRC)-like formation was observed after the super-sonic/Alfvénic collisional merging of two FRCs in FAT-CM device at Nihon University. In this experiment, were generated initially separate theta-pinch type regions. Those regions are coaxially connected to opposite ends a cylindrical confinement chamber. The formed oppositely-translated and collide middle chamber velocity. During collision, merged plasmoid experiences destructive...
The resonant interaction between magnetohydrodynamic (MHD) instability modes and the externally applied helical magnetic field is demonstrated in Saskatchewan Torus-Modified (STOR-M) tokamak. study conducted both numerically experimentally using a 2D MHD equilibrium code former an ( l = 2, n 1) coil carrying short current pulse latter. It shown that can efficiently suppress islands resonating on m surface when value of safety factor at plasma edge relatively low (⩽4). also found (2, are...
A compact toroid (CT) injector was developed for the C-2 device, primarily refueling of field-reversed configurations. The CTs are formed by a magnetized coaxial plasma gun (MCPG), which consists cylindrical electrodes and bias coil creating magnetic field. First, ring is generated discharge between accelerated Lorenz self-force. Then, captured an interlinkage flux (poloidal flux). Finally, fully CT ejected from MCPG. MCPG described herein has two gas injection ports that arranged...
Abstract TAE Technologies’ fifth-generation fusion device, C-2W (also called ‘Norman’), is the world’s largest compact-toroid device and has made significant progress in field-reversed configuration (FRC) plasma performance. produces record breaking, macroscopically stable, high-temperature advanced beam-driven FRC plasmas, dominated by injected fast particles sustained steady state, which primarily limited neutral-beam (NB) pulse duration. The NB power supply system recently been upgraded...
The first experimental result of high power (14 kV, 23 A) neutral beam (NB) injection into a high-beta field-reversed configuration (FRC) is demonstrated. makes it clear that the NB improves plasma performance, increasing lifetime more than 200% in comparison with ordinary FRC under similar conditions. A novel system presented for application to plasmas. set three concave electrodes extraction used focus enabling pass through narrow port. target large bore contained mirror field ratio 2–9.
A repetitively driven compact toroid (CT) injector has been developed for the large field-reversed configuration (FRC) facility of C-2/C-2U, primarily particle refueling. CT is formed and injected by a magnetized coaxial plasma gun (MCPG) exclusively C-2/C-2U FRC. To refuel particles long-lived FRCs, multiple injections are required. Thus, multi-stage discharge circuit was multi-pulsed injection. The drive frequency this system can be adjusted up to 1 kHz number shots per two; further...
Deformation of the internal structure a field-reversed configuration (FRC) was studied using tomographic reconstruction technique. A simple and configurable system developed, with which time evolution FRC reconstructed. In latter phase equilibrium, has well-known global rotational instability toroidal mode number n=2. It been believed that elliptical deformation allows interaction between wall plasma, terminates this configuration. However, these experiments revealed to deform into...
In compact torus injection (CTI) experiments on the STOR-M tokamak, an ion Doppler spectrometer is installed to observe effects of CTI toroidal plasma flows. The intrinsic flow in ohmic discharges without sheared with counter current core region and co-current direction at periphery. With tangential along direction, velocity decreases by more than 5 km s−1, while periphery increases 3–4 s−1. These data indicate that observed change due momentum. Density increase high soft x-ray emission...
Field-reversed configuration (FRC) Amplification via Translation–Collisional Merging (FAT-CM) experiments have recently commenced to study physics phenomena of colliding and merged FRC plasma states. Two independently formed FRCs are translated into the confinement region FAT-CM device, collided near mid-plane device with a relative speed up ∼400 km/s, final state is achieved. To measure internal magnetic field profiles plasmas as well understand its collisional-merging process, an probe...
Rapid magnetic reconnection was experimentally observed to occur within a microsecond timescale, leading the field-reversed configuration (FRC) comprising single closed field structure. The compressibility of plasma FRC played crucial role in accelerating coalescence process, making it considerably faster than resistive process. A strong similarity between experimental results and those solar flare loops indicates that astrophysical phenomena laboratory plasmas are governed by common physics.
Experiments on additional heating by neutral beam injection and application of a low frequency wave to plasma with an extremely high averaged beta value about 90% - field reversed configuration (FRC) are carried out using the FRC Injection Experiment (FIX) apparatus. These experiments made possible translating produced in formation region theta pinch confinement order secure better accessibility facilities control density. By determining appropriate geometry mirror ratio region, it became...
A constructed diagnostic system consisting of a 60-channel set optical detectors with flexible viewing configurations is realized to investigate three-dimensional magnetohydrodynamic (MHD) motions and the internal structure field-reversed configuration (FRC) plasma. The can detect radiation from plasma in wavelength range 420–820 nm. Optical filters are used select ranges required experiment. sensitivities all calibrated using FRC at quiescent phase. Radiation profiles measured by orthogonal...
A field-reversed configuration (FRC) plasma was translated into a weakly ionized and the effects of heating particle buildup FRC due to background neutral particles injection in translation process were investigated. Improvement poloidal flux confinements delay onset n=2 rotational instability observed process. It found that internal structure pressure (plasma temperature density) at separatrix field null deformed by injection. through equivalent an end-on beam plasma. Particles energy...
Experimental evidence for the global stabilization effect of neutral beam injection on field-reversed configuration (FRC) plasma has been found first time. The translation FRC plasma, i.e., transferring formed into another vessel along a gradient guiding magnetic field, is an important technique both current experiments and future fusion reactor to separate formation confinement regions. However, translation’s dynamic process causes wobble movement column. induced by obliquely injected beams...
An internal magnetic probe array has been developed to observe the three components of field simultaneously in vicinity collision surface two colliding plasmoids at supersonic/Alfvénic velocity. Collisional-merging formation a field-reversed configuration (FRC) conducted (FRC Amplification via Translation-Collisional Merging) device Nihon University. Significant plasma heating and an increase trapped poloidal flux have observed during/after collisional-merging process FAT-CM device. In this...