Project/Area Number |
17360440
|
Research Category |
Grant-in-Aid for Scientific Research (B)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Nuclear fusion studies
|
Research Institution | Tokyo Institute of Technology |
Principal Investigator |
TSUTSUI Hiroaki Tokyo Institute of Technology, Research Laboratory for Nuclear Reactors, Assistant Professor (20227440)
|
Co-Investigator(Kenkyū-buntansha) |
SHIMADA Ryuichi Tokyo Institute of Technology, Research Laboratory for Nuclear Reactors, Professor (40206181)
TSUJI-IIO Shunji Tokyo Institute of Technology, Research Laboratory for Nuclear Reactors, Associate Professor (90272723)
NOMURA Shinichi Tokyo Institute of Technology, Integrated Research Institute, Researcher (90401520)
TANI Keiji JAEA, 那珂核融合研究所・核融合研究開発部門, Senior Principal Researcher (00446452)
NAKAMURA Yukiharu JAEA, 核融合炉システム研究グループ, Senior Principal Researcher (80354570)
|
Project Period (FY) |
2005 – 2007
|
Project Status |
Completed (Fiscal Year 2007)
|
Budget Amount *help |
¥16,780,000 (Direct Cost: ¥15,400,000、Indirect Cost: ¥1,380,000)
Fiscal Year 2007: ¥5,980,000 (Direct Cost: ¥4,600,000、Indirect Cost: ¥1,380,000)
Fiscal Year 2006: ¥4,500,000 (Direct Cost: ¥4,500,000)
Fiscal Year 2005: ¥6,300,000 (Direct Cost: ¥6,300,000)
|
Keywords | spherical torus / alpha particle / ripple / force-balanced coil / virial theorem / finite larmor radius effect / stress / internal transport barrier / リップル立鳴拡散 / リップル共鳴拡散 / 磁気エネルギー回生スイッチ / 拡散係数 |
Research Abstract |
Stress distributions of a compact tokamak device Tbdoroki-II with TF-CS hybrid type forte-balanced coils were measured. The measured values were similar to analytically evaluated values, and the reduction of stress was experimentally confirmed.] A fully-inonduced current start up process of a spherical torus (ST) with a transport model of CDBM was numerically simulated. This results show the possibility of a current oscillation by interactions of profiles of internal transport barrier, pressure and boot strap current. A possibility of an over-drive of plasma current was also shown. A finite Larmor radius effect in ST is important because of the weakness of magnetic field compared with that of conventional tokamak. A computation code to calculate trajectory and diffusion coefficient without guiding center approximation was developed. The results were compared with those of conventional tokamak by guiding center approximation. Especially, we investigated an anomalous diffusion by a resonance of toroidal field ripple and banana particles, and evaluated an energy dependence of the diffusion coefficients. The result shows that Larmor motion affects the toroidal phase of banana tip, and softens the resonance. In order to investigate the physical mechanism of the resonance, we use the simple equilibrium configuration with a circular cross section of a conventional tokamak. We numerically found that the peaks of diffusion coefficients appears around the resonance energies of axisymmetric magnetic field. Moreover, distortion of trajectories by the resonance in a phase space makes island configurations, transverse motions by collisions enhance the diffusion.
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