RF Heating of Spherical Tokamak Plasmas

球形托卡马克等离子体的射频加热

• 批准号: 10308018
• 负责人: TAKASE Yuichi
• 金额: $ 8.51万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10308018/
• 关键词: Spherical Tokamak; ST; RF Heating; RF; Wave; Fast Wave; HHFW; Combline Antenna; プラズマ; 核融合; トカマク; 高周波; 加熱

The Spherical Tokamak (ST) can produce high performance plasmas in a small device. The most important issue for the ST is plasma current rampup and maintenance by noninductive means. The high-harmonic fast wave (HHFW) in the ion-cyclotron frequency range has good propagation and absorption characteristics in ST plasmas with very high dielectric constants. the aim of this study is to study excitation, propagation, and absorption of HHFW. It is indispensable to produce and, maintain a plasma with high enough density for HHFW excitation and high enough electron temperature for its absorption. The TST-2 device was constructed for this purpose and plasmas with the required density and temperature were achieved. A traveling wave antenna called the combline antenna was adopted for wave excitation. Based on optimization using mockup antennas, a six-element antenna was fabricated for the experiment. Magnetic probes installed at various locations on the vacuum vessel wall were used for wave dete … More ction- The plasma loading resistance varied as the plasma evolved, and reached a maximum when the plasma current reached a peak, as expected. On the inboard side (high field side) of the torus, the nonuniformity in the toroidal direction is weak (about 5dB) and the vertical nonuniformity was even weaker. In contrast, the outboard probes detected stronger signals by 10-15dB compared to inboard probes. These results are consistent with the TASK/WM full-wave code. In addition, plasma currents of up to 1.2kAwere achieved with 1kW of electron cyclotron wave. In the presence of a mirror magnetic field configuration in the vertical direction, electrons produced by ionization are trapped by the mirror field and a current can flow by their drill: motion, and subsequently pressure driven currents can flow. If the plasma can be formed and the plasma current can be ramped up by RF waves as shown in these experiments, the central solenoid becomes unnecessary and the attractiveness of the ST as a fusion reactor is greatly enhanced. Less

球形托卡马克（ST）可以在小型设备中产生高性能等离子体，其最重要的问题是离子回旋加速器频率范围内的等离子体电流斜坡上升和维持。具有非常高介电常数的 ST 等离子体中良好的传播和吸收特性是研究 HHFW 的激发、传播和吸收所必需的。为此目的构建了具有足够高密度的等离子体以用于 HHFW 激发和足够高的电子温度以用于其吸收，并且采用了一种称为梳状天线的行波天线来实现具有所需密度和温度的等离子体。基于使用模型天线的优化，安装在真空容器壁上不同位置的六元件天线用于波检测——等离子体负载电阻随着等离子体的演化而变化，并达到正如预期的那样，当等离子体电流达到峰值时，在环面的内侧（高场侧），环面方向的不均匀性较弱（约5dB），并且垂直方向的不均匀性更弱。与内侧探头相比，外侧探头检测到的信号强 10-15dB。此外，等离子体电流高达 10-15dB。通过 1kW 的电子回旋波实现了 1.2kA 在垂直方向存在镜面磁场配置的情况下，电离产生的电子被镜面场捕获，并且电流可以通过其钻头流动：运动，以及随后的压力驱动电流。如果可以形成等离子体并且可以通过射频波增加等离子体电流，那么中央螺线管就变得不必要，并且ST作为聚变反应堆的吸引力大大增强。

项目成果

T.Toyama.: "Comparative studies of spherionl tokamak and condentional tokamek" Fusion Enargy 1998 (Proc.17th Int.Canf.) IAEA. (to be published). (1999)

T.Toyama.：“球形托卡马克和条件托卡马克的比较研究”Fusion Enargy 1998（Proc.17th Int.Canf.）IAEA。

S. Shiraiwa: "Construction, operational scenarios, and research plans of TST-2"Controlled Fusion and Plasma Physics. 23J. 441-444 (1999)

S. Shiraiwa：“TST-2 的构造、操作场景和研究计划”受控聚变和等离子体物理。

Y, Takase: "TST-2 : The new spherical tokamak at the University of Tokyo"Bulletin of the American Physical Society. 44(1). 588-588 (1999)

Y，Takase：“TST-2：东京大学的新型球形托卡马克”美国物理学会公报。

Y. Takase: "Spherical Tori"Nuclear Fision. 39(8). 1057-1068 (1999)

Y. Takase：“球形托里”核裂变。

Y. Takase: "Initial results from the TST-2 spherical tokamak"Bulletin of the Americal Physical Society. 44(7). 271-271 (1999)

Y. Takase：“TST-2 球形托卡马克的初步结果”美国物理学会公报。