Thakur S Chakraborty, Harvey Z, Biloiu I A, Hansen A, Hardin R A, Przybysz W S, Scime E E
Department of Physics, West Virginia University, Morgantown, West Virginia 26506-6315, USA.
Phys Rev Lett. 2009 Jan 23;102(3):035004. doi: 10.1103/PhysRevLett.102.035004.
We report observations that confirm a theoretical prediction that formation of a current-free double layer in a plasma expanding into a chamber of larger diameter is accompanied by an increase in ionization upstream of the double layer. The theoretical model argues that the increased ionization is needed to balance the difference in diffusive losses upstream and downstream of the expansion region. In our expanding helicon source experiments, we find that the upstream plasma density increases sharply at the same antenna frequency at which the double layer appears.
我们报告的观测结果证实了一项理论预测，即在等离子体膨胀进入更大直径的腔室时，无电流双层的形成伴随着双层上游电离的增加。理论模型认为，需要增加电离来平衡膨胀区域上游和下游扩散损失的差异。在我们的膨胀螺旋波源实验中，我们发现，在双层出现的相同天线频率下，上游等离子体密度急剧增加。
