权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

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.低杂波在等离子体中的传播和参数衰减不稳定性的产生我们可以控制低杂波的传播，方法是使用围绕等离子体柱的慢波导电路，控制平行于磁场的波数k和外加射频功率的频率。详细研究了参数衰变不稳定的条件与外加射频功率的关系。通过对边带波和低频波的频率和波数谱的观测，确定它们是一种低杂波和离子回旋波。控制射频功率的不稳定性和对等离子体中心的穿透我们可以通过增加外加射频功率的频谱宽度来增加产生不稳定性的射频功率的占有率，从而保持整个外加射频功率。结果表明，通过抑制不稳定引起的等离子体表面加热，射频功率可以穿透到等离子体中心。等离子体中心的局部加热和加速低杂波可以到达等离子体中心，捕获电子并加速它们。结果是，电子有一个束流分量。另一方面，在施加射频功率后，由于静电势的空间变化产生的加速效应，产生束状离子，在失稳发生后，电子受到边带波及其谐波的加速加热。这些结果对托卡马克等离子体的电流驱动和等离子体加热的模型实验具有重要的意义。