A5091701528- Magnetic confinement fusion research
- Superconducting Materials and Applications
- Fusion materials and technologies
- Particle accelerators and beam dynamics
- Granular flow and fluidized beds
- Particle Dynamics in Fluid Flows
- Radioactivity and Radon Measurements
- Magnetic Field Sensors Techniques
- Nuclear Physics and Applications
- Fluid Dynamics Simulations and Interactions
- Geotechnical Engineering and Soil Mechanics
- Physics of Superconductivity and Magnetism
- Radioactive contamination and transfer
- Nuclear reactor physics and engineering
- Ionosphere and magnetosphere dynamics
- Fire effects on ecosystems
- Nuclear and radioactivity studies
- Coastal and Marine Dynamics
- Coagulation and Flocculation Studies
- Plasma Diagnostics and Applications
Japan Atomic Energy Agency
1980-2024
National Institutes for Quantum Science and Technology
2016-2023
The concept for a compact DEMO reactor named 'SlimCS' is presented. Distinctive features of the are low aspect ratio (A = 2.6) and use reduced-size centre solenoid (CS) which has function plasma shaping rather than poloidal flux supply. CS enables us to introduce thin toroidal field coil system contributes reducing weight perhaps lessening construction cost. Low-A merits vertical stability high elongation (κ) normalized beta (βN), leads power density with reasonable physics requirements....
Abstract Plasma with an internal transport barrier (ITB) will be developed in JT-60SA as attractive operation appropriate for a steady-state fusion reactor. To achieve the ITB plasma while avoiding magnetohydrodynamic instabilities, it is advantageous to simultaneously control safety factor ( q ) profile and normalized beta <?CDATA $\beta_\mathrm{N}$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>β</mml:mi> <mml:mrow> <mml:mi...
Energetic ion transport due to microturbulence is investigated in magnetohydrodynamic-quiescent plasmas by way of neutral beam injection the DIII-D tokamak [J. L. Luxon, Nucl. Fusion 42, 614 (2002)]. A range on-axis and off-axis scenarios are employed vary relevant parameters such as character background value Eb/Te, where Eb energetic energy Te electron temperature. In all cases, it found that any enhancement too small observe experimentally. These effects modeled using numerical analytic...
Safety factor profile control via active feedback of electron temperature during a plasma current ramp-up phase DEMO reactor is investigated to minimize the magnetic flux consumption central solenoid (CS) for wide range q profiles. It shown that profiles with positive, weak and reversed shear can be obtained resistive less than 60% empirical estimation which calculated using Ejima constant 0.45. For optimization target gain heating power, reinforcement learning technique introduced. One...
This paper presents numerical simulations using the discrete element method (DEM) to model sedimentation behavior of solid debris particles, which is significant for estimates coolability beds. A series experiments gravity driven discharge particles into a quiescent water pool was used validate DEM simulation method. We evaluated effects three crucial factors: particle density, diameter, and nozzle diameter on key quantitative parameters: dispersion angle, fall time in pool, height deposited...
Current ramp-up with reduced central solenoid (CS) flux consumption in JT-60SA has been investigated using an integrated modeling code suite (TOPICS) a turbulent model (CDBM). The plasma current can be ramped-up from 0.6 MA to 2.1 no additional CS if the is overdriven by neutral-beam-driven and bootstrap current. A time duration required for without becomes as long 150 s scenario we have examined. In order achieve overdrive condition MA, drive lower energy neutral beam (85 keV) effective....
H-modes operated at higher l i with the current ramp down have shown energy confinement density in JT-60U. The H -factor evaluated for core plasma depends strongly on relation of case without sawtooth activities. Centre peaked profiles electron and temperature are obtained high H-modes. While peripheral largely modified by ramp, pedestal pressure is not significantly changed. enhanced attributed to improvement while no explicit difference profile observed. heat diffusivity reduced case,...
Abstract The method for reducing a poloidal magnetic flux consumption of external coils is investigated to reduce the size central solenoid (CS) in DEMO reactor. reduction during plasma current ramp-up phase by electron cyclotron (EC) heating using an integrated modeling code suite, TOPICS. A strongly reversed shear q profile tends be produced if intense off-axis EC applied obtain large consumption. In order overcome this tendency, we find optimum temperature which minimizes wide range...
High densities exceeding the Greenwald limit by a factor of 1.7 have been obtained in L-mode discharges with high internal inductances i l as 2.8 JT-60U.The inductance is controlled ramping down plasma current.In addition to extension operational regime limited disruptions, confinement performance remains good an H89PL 1.6 even above limit.While earlier study has indicated core improvement due enhancement poloidal field, additional tolerance against density turned out be correlated edge...
Transport of neutral particles in a toroidal plasma is treated the same manner as that neutrons by Monte Carlo method. A new sampling technique flight-path length proposed for torus geometry. Several routines relating to geometry have been developed and incorporated into neutron gamma-ray transport code “MORSE.” Results obtained from sample calculations check cylindrical approximation show hot neutrals escape more easily than cylinder, while cold are retained better cylinder. Furthermore,...