Research on Disruption and Thermal Quench of Long-Pulse Discharge

长脉冲放电的破坏与热猝灭研究

• 批准号: 05680398
• 负责人: NAKAMURA Kazuo
• 金额: $ 1.02万
• 依托单位: KYUSHU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05680398/
• 关键词: Long-pulse discharge; Disruption; Thermal quench; Current disruption; Lower hybrid current drive; 長時間放置; デイスラプション

(1) Controllable plasma current density distribution is obtainable by numerical calculation of ray-trace and Fokker-Planck equations. We developed the numerical calculation program and applied it to the 8.2 GHz LHCD plasma. Although the absolute driven current depends on the model of energy gap, the dependence of the driven plasma current profile on the line-averaged electron density coincides the dependence of the profile estimated from the measured hard X-ray profile emitted from high-energy electrons.(2) We measured the impurity density distribution of 8.2 GHz LHCD discharge with multi-channel vacuum ultra violet spectrometer. Molybdenum impurity, which is the material of the poloidal limiter, increases temporally, and results in discharge termination. This phenomenon suggests the thermal quench due to impurity emission cooling and following current disruption.(3) To avoid the impurity increase in the plasma, we made a single-null divertor configuration in the superconducting tokamak TRIAM-1M.Assuming the thermal load profile onto te divertor plate, we calculated 2-dimentional temperature distribution in the divertor plate and the stainless steel supporting plate. By comparing the result with the temperature of the water-cooled stainless steel plate measured by CA thermo-couple, the total thermal load onto the divertor plate was estimated to be 20-35 % of the RF input power.(4) What current profile does a plasma realize in steady state? This problem coincides the problem what confinement is realized in steady state. We studied theoretically on the effect of the current profile on the transport coefficient. And we formulated an element of "profile control research" from the view point of "plasma confinement". According to the formulation, we studied theoretically on the confinement improvement phenomena concerning LHCD and high-beta oriented experiments.

（1）可通过射线跟踪和fokker-Planck方程的数值计算可获得可控的等离子体电流密度分布。我们开发了数值计算程序，并将其应用于8.2 GHz LHCD等离子体。尽管绝对驱动的电流取决于能量差距的模型，但驱动的等离子体电流对线平均电子密度的依赖性重合从高能电子中发出的测量硬X射线轮廓估计的轮廓的依赖性。（2）我们测量了8.2 GHZ LHCD Exproum coft coft coft coft coft coft coft coft coft coft coft coft coft coft coft coft coftry ulter ultr ulter ultrer ultrer。钼杂质（是螺状限制物的材料）会增加时间，并导致排放终止。 This phenomenon suggests the thermal quench due to impurity emission cooling and following current disruption.(3) To avoid the impurity increase in the plasma, we made a single-null divertor configuration in the superconducting tokamak TRIAM-1M.Assuming the thermal load profile onto te divertor plate, we calculated 2-dimentional temperature distribution in the divertor plate and the stainless steel supporting plate.通过将结果与通过CA热蛋白测量的水冷不锈钢板的温度进行比较，据估计，到分离板上的总热载荷是RF输入功率的20-35％。（4）等离子体在稳态中会意识到哪些当前轮廓？这个问题恰逢该问题以稳定状态实现的限制。我们从理论上研究了当前轮廓对传输系数的影响。我们从“等离子体限制”的角度从“配置文件控制研究”制定了一个元素。根据该公式，我们从理论上研究了有关LHCD和面向高β的实验的禁闭现象。

项目成果

K.Itoh, et al.: "Cross Field Ion Motion at Sawtooth Crash" J.Phys.Soc.Jpn.62. 399-402 (1993)

K.Itoh 等人：“锯齿碰撞时的跨场离子运动”J.Phys.Soc.Jpn.62。

M.Yagi, et al.: "Analysis of the Current-Diffusive Ballooning Mode" Phys.Fluids B. 5. 3702-3711 (1993)

M.Yagi 等人：“电流扩散气球模式的分析”Phys.Fluids B. 5. 3702-3711 (1993)

K.Itoh, et al.: "Beta-Limiting Phenomena due to Global Resistive Interchange Mode in High-Aspect-Ratio Torsatron/Heliotron" Plasma Phys.Contr.Fusion. 35. 723-732 (1993)

K.Itoh 等人：“高纵横比 Torsatron/Heliotron 中全局电阻交换模式导致的 Beta 限制现象”等离子 Phys.Contr.Fusion。

K.Itoh: "Self-sustained Turbulence and L-mode Confinement in Toroidal Plaamas II" Plasma Phys.Control.Fusion. 36. 1501-1520 (1994)

K.Itoh：“环形等离子体 II 中的自持湍流和 L 模式限制”等离子体物理控制融合。

伊藤 早苗: "On Scaling Laws in Scrape-off-layer Plasmas" Plasma Phys.Control.Fusion. 36. 1845-1851 (1994)

伊藤早苗：“论刮离层等离子体的缩放定律” Plasma Phys.Control.Fusion 36。1845-1851 (1994)