Study on neutral particle behavior in non-axisymmetric minimum-B region of a tandem mirror

串列镜非轴对称最小B区中性粒子行为研究

• 批准号: 15540467
• 负责人: NAKASHIMA Yousuke
• 金额: $ 1.79万
• 依托单位: University of Tsukuba
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15540467/
• 关键词: Tandem Mirror; Neutral Hydrogen Atoms and Molecules; H-Alpha Line-emission Measurement; Non-axisymmetric Structure; Monte-Carlo Simulation; DEGAS Code

The objective of this research is to measure he Hydrogen Balmer-alpha(Hα) line emission from the anchor cell and from the transition region in the anchor minimum-B region. We also performed a neutral transport simulation using a Monte-Carlo code "DEGAS". In this simulation, the density and temperature profiles of hydrogen atoms and molecules are predicted in non-axismmetric anchor mirror cell and hence a important knowledge with particle transport in such complicated configuration of this magnetic structure.In the last fiscal year, a newly designed two-dimensional Hα detector array was constructed. In order to measure the line emission from the narrow viewing area, the detector was required to obtain a high spatial resolution and its characteristics of the detector were investigated by using a standard lamp. A three-dimensional Monte-Carlo neutral particle simulation code "DEGAS ver.63" was applied to the GAMMA 10 anchor cell for the first time and a simulation study in this region was … More started. A preliminary mesh model was constructed and three-dimensional simulation was carried out. From this simulation, it was found that two particle sources (mirror throat gas puffer and a limiter at the outer transition region of the anchor cell) successfully explain the measured results of Hα line-emission in the anchor cell.In this fiscal year, the first measurement of detailed structure of the Hα line-emission in the anchor outer-transition region was successfully performed using the above detector array. It was found that the measured Hα line intensity has a strong peak along the miner axis of elliptically elongated plasma cross-section. On the contrary, in an axial direction along the magnetic field line, the spatial profile of the line intensity became flat. In order to explain the obtained results, a new mesh model covering from the anchor cell to the plug/barrier cell was constructed and detailed simulation based on the realistic structure of these cells was performed. The simulation results considering a particle source from the limiter at this region showed a good agreement with the measured profiles. A unified mesh mode covering from the central-cell to the anchor-cell was successfully built up, which enabled to precisely simulate the neutral transport in the connecting region between the two cells efficiently. From the above results, the three-dimensional structure of plasma and vacuum chamber wall plays an important roll in neutral transport in this region. Less

本研究的目的是测量锚定细胞和锚定最小- b区过渡区的氢离子α (Hα)线发射。我们还使用蒙特卡罗代码“DEGAS”进行了中性传输模拟。在此模拟中，预测了非轴对称锚定镜像细胞中氢原子和分子的密度和温度分布，从而获得了在这种复杂的磁结构构型中粒子输运的重要知识。在上一财政年度，新设计的二维Hα探测器阵列被构建。为了测量窄视场的线发射，要求探测器具有较高的空间分辨率，并采用标准灯对探测器的特性进行了研究。三维蒙特卡罗中性粒子模拟代码“DEGAS ver”。GAMMA 10锚定单元首次使用了63”，并在该区域进行了模拟研究。建立了初步的网格模型，并进行了三维仿真。模拟结果表明，两个粒子源（镜面喉道气体泵浦器和锚细胞外过渡区的限制器）成功地解释了锚细胞中Hα线发射的测量结果。在本财政年度，利用上述探测器阵列成功完成了锚外过渡区Hα线发射详细结构的首次测量。结果表明，测量到的α线强度沿椭圆细长等离子体截面的矿轴方向有一个强峰。相反，沿磁力线轴向，磁力线强度的空间分布趋于平坦。为了解释得到的结果，构建了一个新的网格模型，覆盖了锚定单元和堵塞/屏障单元，并基于这些单元的真实结构进行了详细的模拟。考虑该区域限制器粒子源的模拟结果与实测剖面吻合较好。成功地建立了从中心细胞到锚细胞的统一网格模式，能够有效地精确模拟两个细胞之间连接区域的中性传输。从以上结果可以看出，等离子体和真空室壁的三维结构对该区域的中性输运起着重要的作用。少

项目成果

M.K.Islam, Y.Nakashima, et al.: "Fusion oriented plasma research in Bangladesh : Impact of dust plasma"Nuclear Fusion. 43No.9. 914-921 (2003)

M.K.Islam、Y.Nakashima 等人：“孟加拉国的聚变导向等离子体研究：尘埃等离子体的影响”核聚变。

Neutral Beam Injection Experiments and Related Behavior of Neutral Particles in the GAMMA 10 Tandem Mirror

GAMMA 10 串联镜中中性束注入实验及中性粒子的相关行为

• 发表时间: 2005
• 期刊: Transaction of Fusion Technology 47 No.1T
• 作者: Y.Nakashima;et al.
• 通讯作者: et al.

Y.Nakashima, et al.: "Neutral transport analysis in non-axisymmetric anchor region of the GAMMA 10 tandem mirror using a Monte-Carlo simulation"Journal of Plasma and Fusion Research, SERIES. 6(印刷中). (2004)

Y. Nakashima 等人：“使用蒙特卡罗模拟对 GAMMA 10 串联镜的非轴对称锚定区域进行中性输运分析”，《等离子体与聚变研究杂志》，系列 6（2004 年出版）。

Neutral transport analysis in non-axisymmetric anchor region of the GAMMA 10 tandem mirror using a Monte-Carlo simulation

使用蒙特卡罗模拟对 GAMMA 10 串联镜的非轴对称锚定区域进行中性输运分析

• 发表时间: 2005
• 期刊: Journal of Plasma and Fusion Research, SERIES 6(印刷中)
• 作者: Y.Nakashima;et al.
• 通讯作者: et al.

Y.Ishimoto, Y.Nakashima, et al.: "Development of Carbon Sheet pump for control of hydrogen recycling in the GAMMA 10 tandem mirror"Fusion Engineering Design. 65No.3. 429-432 (2003)

Y.Ishimoto、Y.Nakashima 等人：“开发用于控制 GAMMA 10 串联镜中氢气回收的碳片泵”聚变工程设计。