Study of Ultrashort-Pulse Microwave-Plasma Interaction and its Application to Plasma Diagnostics

超短脉冲微波-等离子体相互作用研究及其在等离子体诊断中的应用

• 批准号: 08558044
• 负责人: MASE Atsushi
• 金额: $ 5.12万
• 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 (A)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08558044/
• 关键词: Ultrashort Pulse; Microwave; Radar; Ultrafast Electron Device; Plasma Diagnostics; Particle Acceleration; Millimeter-Wave MMIC

1) During the period of this research project, an ultrashort-pulse reflectometer (USPR) has heen fabricated.i) Input source utilizes a 8 V,65 psec full-width half-maximum (FWHM) pulse which is stretched into a chirped pulse by a dispersive waveguide. The resultant waveform is amplified (23 dB,6-18 GHz) and irradiated via X-band horn into a plasma. ii) The received waveform is amplified (40 dB,6-18 GHz), and then filtered/detected via an 8 channel receiver system, comprising frequency channels spanning 8-15 GHz at 1.0 GHz intervals. The detector output i s sampled and stored using a fast digitizer (10 GS/sec, 750 MHz bandwidth). A constant fraction discriminator and time-to-amplitude converter (TAC) enables time-of flight measurements with a high repetition (>200 kHz) and high resolution (25 psec) measurements.2) The USPR system for electron density profile and density fluctuation measurements has heen applied to the GAMMA 10 tandem mirror. The observed values of the time-of-flight are … More in agreement with those calculated using the Abel-inverted profile from interferometry data. The oscillation of the cut-off layr is observed from the time-of-flight measurement using TAC.The frequency spectrum of the oscillation agrees with that of the microwave scattering signal.3) Ultrafast FM reflectometers (8-26 GHz) have been applied to GAMMA 10. The density profiles are reconstructed using several analysis methods. It is found that the profile reconstruction improves for sweeping faster than 20-30 mus. The results shows that the demands on the sweep rate becomes low when the data analysis method is improved.4) Diagnostic simulator models performing computer experiments on USPR diagnostics is presented. The models decribe 2-dimensional cold magnetized plasma, and the full Maxwell equations are solved numerically to describe propagation, reflection, and scattering of microwaves. The effects of waveguide for incident waves and wall boundary of vacuum vessel are included. The appropriate parameters of the USPR (frequency pulse width, etc.) is clarified in order to apply any magnetic confinement systems.5) Interaction of charged particles with dispersive electrostatic pulses is numerically investigated. It is found that the dispersive pulses can essentially trap and/or accelerate electrons as other type of pulses and sinusoidal waves. This trapping can play a significant role in Langmuir turbulence generated by relatively low-density electron beams.6) Fully monolithic detector with integration of antenna, mixer and amplifier is fabricated, and applied to the plasma daignostics for the first time. Less

1)本课题研制了一台超短脉冲反射计（USPR），输入源采用8V、65 psec半峰全宽（FWHM）脉冲，经色散波导展宽成啁啾脉冲。将所得波形放大（23 dB，6-18 GHz）并通过X波段喇叭辐射到等离子体中。ii）接收的波形被放大（40 dB，6-18 GHz），然后经由8信道接收器系统被滤波/检测，该8信道接收器系统包括以1.0GHz间隔跨越8-15 GHz的频率信道。使用快速数字转换器（10 GS/sec，750 MHz带宽）对检测器输出进行采样和存储。采用恒分数线和时间-幅度转换器（TAC）实现了高重复率（>200 kHz）和高分辨率（25 psec）的飞行时间测量。2）USPR电子密度分布和密度起伏测量系统已应用于伽马10串列镜。飞行时间的观测值为 ...更多信息 与使用来自干涉测量数据的Abel反演轮廓计算的那些一致。利用TAC测量了截止层的振荡，其频谱与微波散射信号的频谱一致。3）超快FM反射计（8-26 GHz）已应用于伽马10。密度分布重建使用几种分析方法。研究发现，扫描速度超过20-30 μ s时，轮廓重建效果有所提高。结果表明，随着数据分析方法的改进，对扫描速率的要求变得较低。4）提出了对USPR诊断进行计算机实验的诊断模拟器模型。该模型描述了二维冷磁化等离子体，和完整的麦克斯韦方程数值求解来描述微波的传播，反射和散射。考虑了波导对入射波的影响和真空容器壁面边界的影响。USPR的适当参数（频率脉冲宽度等）的澄清，以适用于任何磁约束系统。5）带电粒子与色散静电脉冲的相互作用的数值研究。结果表明，色散脉冲与其他类型的脉冲和正弦波一样，可以捕获和加速电子。这种捕获在相对低密度电子束产生的朗缪尔湍流中发挥了重要作用。6）研制了集天线、混频器和放大器于一体的单片探测器，并首次应用于等离子体探测。少

项目成果

A., Mase・L.G., Bruskin.et al.: "Measurement of Magnetic Fluctuations of Electromagnetic Plasma Waves by Cross-Polarization Scattering" Review of Scientific Instruments. 68・1. 454-457 (1997)

A.，Mase・L.G.，Bruskin.et al.：“通过交叉极化散射测量电磁等离子体波的磁波动”科学仪器评论 68・1（1997 年）。

N., Oyama・A., Mase・et al.: "Millimeter-Wave Two-Dimensional Imaging Array for the Γ 10 Tandem Mirror" Review of Scientific Instruments. 68・1. 500-503 (1997)

N.、Oyama・A.、Mase・等人：“用于 Γ 10 串联镜的毫米波二维成像阵列”科学仪器评论 68・1（1997 年）。

間瀬 淳・徳沢 季彦・他: "マイクロ波反射計による密度分布および揺動計測" 第14回プラズマ核融合学会年会予稿集(招待講演). 320-321 (1997)

Jun Mase、Tokihiko Tokuzawa 等人：“使用微波反射计进行密度分布和波动测量”等离子体聚变学会第 14 届年会论文集（邀请报告）320-321（1997 年）。

N., Takada・M., Nagatsu・et al.: "Reflectivity Characteristics of Carbon Materials Irradiated with Hydrogen Ion-Beam" Journal of Plasma and Fusion Research. 72・8. 776-782 (1996)

N.，Takada·M.，Nagatsu·等人：“氢离子束照射的碳材料的反射率特性”等离子体与聚变研究杂志72·8（1996）。

間瀬 淳: "マイクロ波反射計によるプラズマ計測" プラズマ核融合学会-第35回若手夏の学校講義テキスト. 130-148 (1996)

Jun Mase：“使用微波反射计进行等离子体测量”等离子体融合协会 - 第 35 届青少年暑期学校讲座文本 130-148 (1996)。