Project/Area Number |
16360464
|
Research Category |
Grant-in-Aid for Scientific Research (B)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Nuclear fusion studies
|
Research Institution | Japan Atomic Energy Agency |
Principal Investigator |
NAKAMURA Yukiharu JAEA, Fusion Research and Development Directorate, Principal Researcher, 核融合研究開発部門, 研究主幹 (80354570)
|
Co-Investigator(Kenkyū-buntansha) |
KOIDE Yoshihiko JAEA, Fusion Research and Development Directorate, Principal Researcher, 核融合研究開発部門, 研究主幹 (70354595)
SAKAMOTO Yoshiteru JAEA, Fusion Research and Development Directorate, Scientist, 核融合研究開発部門, 研究職 (30354583)
TSUTSUI Hiroaki Tokyo Institute of Technology, Research Laboratory for Nuclear Reactors, Research Assistant, 原子炉工学研究所, 助手 (20227440)
SUGIHARA Masayoshi JAEA, Fusion Research and Development Directorate, Senior Principal Researcher, 核融合研究開発部門, 研究主席 (20414550)
TAKECHI Manabu JAEA, Fusion Research and Development Directorate, Scientist, 核融合研究開発部門, 研究職 (40370423)
芳野 隆治 独立行政法人日本原子力研究開発機構, 核融合研究開発部門, 上級研究主席
栗原 研一 独立行政法人日本原子力研究開発機構, 核融合研究開発部門, 研究主幹 (90360411)
|
Project Period (FY) |
2004 – 2006
|
Project Status |
Completed (Fiscal Year 2006)
|
Budget Amount *help |
¥13,100,000 (Direct Cost: ¥13,100,000)
Fiscal Year 2006: ¥3,900,000 (Direct Cost: ¥3,900,000)
Fiscal Year 2005: ¥4,700,000 (Direct Cost: ¥4,700,000)
Fiscal Year 2004: ¥4,500,000 (Direct Cost: ¥4,500,000)
|
Keywords | Internal Transport Barrier / Negative Magnetic Shear Plasma / Advanced Operation Scenario / Disruption / Bootstrap Current / Magneto-Hydrodynamic Simulation / Non-Inductive Current Drive / Self-Organizing Phenomena / 自律的競合現象 / 電流スパイク現象 |
Research Abstract |
Purpose of the present study is to provide practical guideline for fusion reactor design and operation scenario with disruption avoidance. Regarding negative shear plasmas with transport barriers difficult to maintain, we have clarified characteristics of frequent disruptions, and provided a stable pathway to attain high-beta, high bootstrap current plasmas while taking a detour of the disruption avoidance. First, a self-consistent simulation code was developed to model a transport improvement in accordance with the magnetic shear and a consequent formation of the plasma pressure and bootstrap current profiles. Physics models of disruption events such as thermal quench, associated current spike and vertical displacement were formulated. Additionally, physics model of the most common disruption, which has been frequently occurring in low-beta regime discharges, was provided for a guideline along which the disruptions can be avoided. A new neural-net predictor that can be used even for be
… More
ta-limit typed disruption normally observed without any of precursors and thus too hard to predict, was presented and verified by JT-60U experiments. In regard to high confinement plasmas fitting in with high bootstrap current, we presented steady-state, advanced operation scenarios, i.e., non-inductive current ramp-up and recharging of center solenoid current vigorously using the bootstrap current. Moreover, an innovative burning scenario was proposed to control the structure of transport barriers using a small inductive perturbation of externally applied electric field. Underlying mechanism of a beta-collapse with a regular intermittency observed in JT-60U negative shear discharge was clarified that "Return Current" induced by the NBCD turn-off underwent a spatial diffusion to modify the transport barrier, increasing in the stored energy that led to a MHD instability with a destruction profile localized around peripheral region of the negative shear plasma. The study has presented such the important knowledges useful for the sake of disruption avoidance operation scenarios. Less
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