摘要
在 HL- 1M装置上最近改进后的超声分子束流加料实验中 ,发现边缘等离子体的 Hα线辐射信号沿大环方向呈现有序变化。在超声分子束注入口附近区域 ,Hα信号为长方形正脉冲 ,类似于分子束注入脉冲 ,而在远离注入口区域的边缘 Hα信号为负尖脉冲。在注入口附近区域 ,用静电探针测得的径向电子温度和密度在超声分子束注入期间分别下降和上升了一个数量级。CCD相机拍摄分子束与等离子体相互作用产生的 Hα 线辐射强度分布等实验结果表明 ,注入的“冷通道模型”可能是成立的。根据高压气体射流形成团簇的经验定标律Γ * =kd0 .85p0 / T2 .2 90 ,通常Γ * >10 0即有可能出现团簇。本实验中Γ* 的值约为 12 7,有可能形成团簇。分子束流中出现团簇有利于增加注入的深度。在超声分子束注入过程中呈现的新实验现象与团簇的联系有待进一步研究。
The fuelling method with pulsed supersonic molecular beam has been improved in the HL 1M tokamak recently.The edge H α signals show regular variation around the torus.Nearby the injection port,the edge H α signals are positive rectangular wave,which is similar to the injection beam pulses.On the other hand,the H α signals far from the injection channel appear as sharp negative pulses.During beam injection,the edge electron temperature and density measured with movable Langmuir probes decrease and increase by an order of magnitude within the injection sector,respectively.At the same time,the H α intensity due to the interaction of the beam with toroidal plasma is congregated at the injection port.It is taken with CCD camera at an angle of 13.4 o to the hydrogen beam injection line.The experimental results show that the hypothesis of “cold injection passage” should be valid,and a simple model for the “passage” has been discussed. In the present experiment,hydrogen clusters may be produced in the beam.The onset of clustering can be described by an empirical scaling law,Γ =kd 0.85 p 0/T 2.29 0.Usually clusters emerge if Γ >100.In our experiment Γ is about 127.A supersonic beam with clusters will be beneficial to deepening injection.
出处
《核聚变与等离子体物理》
CAS
CSCD
北大核心
2000年第2期115-120,共6页
Nuclear Fusion and Plasma Physics
基金
国家自然科学基金资助项目!(197750 11)
