Parametric Decay Instability near the Lower Hybrid Frequency and RF Plasma Heating

较低混合频率和射频等离子体加热附近的参数衰减不稳定性

基本信息

批准号：
63460220
负责人：
IDEHARA Toshitaka
金额：
$ 4.61万
依托单位：
FUKUI UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1989
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-63460220/
关键词：
Parametic decay instability Lower hybrid wave rf heating Sideband wave Slow waveguiding circuit 低域混成周波数プラズマ加熱サイドバンド

项目摘要

1. Propagation of a lower hybrid wave in a plasma and generation of a parametric decay instabilityWe can control a propagation of lower hybrid wave, by using a slow waveguiding circuit surrounding a plasma column and controlling the wave number k parallel to a magnetic field and the frequency of applied rf power. The conditions for parametric decay instability are studied in detail, as a function of applied rf power. Observed sideband wave and low frequency wave are identified as a lower hybrid wave and an ion cyclotron wave, from observations of their frequency and wavenumber spectrums.2. Control of the instability and penetration of rf power into plasma centerWe can increase the shreshold of rf power for generation of the instability, by increasing the width of frequency spectrum of applied rf power and keep the whole applied rf power. As the results, the rf power can penetrate into the plasma center, by suppressing the heating of plasma surface resulting from the instability.3. Local heating and acceleration at the center of plasmaThe lower hybrid wave can arrive at the plasma center,trap electrons and accelerate them. As the results, electrons have a beam component. On the other hand, just after the rf power is applied, beam-like ions appear, as a result of acceleration effect due to the spatial variation of electrostatic potential.After the instability occurs, electrons are heated by the acceleration due to the sideband wave and its harmonics. The effect is observed by a probe measurement and a spectroscopic measurement.These results have impotent meanings as model experiments for a current drive and plasma heating of tokamak plasmas.

1。在等离子体中的较低混合波的传播和参数衰变不稳定性的产生，我们可以通过使用围绕等离子体柱的慢波电路来控制下部混合波的传播，并控制与磁场和磁场平行的波数k的传播。应用RF功率的频率。详细研究了参数衰减不稳定性的条件，这是应用RF功率的函数。观察到的侧带波和低频波被认为是较低的杂种波和离子回旋体波，从它们的频率和波形光谱的观察结果。2。通过增加应用RF功率的频率频谱的宽度并保持整个应用RF功率，可以控制RF功率进入等离子中心的不稳定性和渗透能力以产生不稳定性的距离。作为结果，RF功率可以通过抑制不稳定性导致的血浆表面加热来渗透到血浆中心中。3。浆膜下部混合波的中心的局部加热和加速度可以到达血浆中心，捕获电子并加速它们。由于结果，电子具有梁成分。另一方面，在施加了射频功率之后，由于静电电势的空间变化而导致的加速度效应，出现了梁状的离子。不稳定性发生后，由于侧带波的加速，电子会加热电子。及其谐波。通过探针测量和光谱测量值观察到这种效果。这些结果对于当前驱动器的模型实验和Tokamak等离子体的血浆加热具有无能的意义。