Depletion of the ground state atomic hydrogen density has been directly measured using two-photon laser-induced fluorescence in a high-density helicon plasma. The depletion is correlated with the plasma pressure becoming increasingly higher than the neutral gas fill pressure. Spatially resolved measurements show depletion of atomic hydrogen in the centre of the discharge chamber. Temporally resolved measurements display a replenishment of atomic hydrogen in the plasma afterglow at high plasma densities in comparison to the typical two-step decay at lower plasma densities.

中文翻译：

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高功率螺旋放电中原子氢的消耗

在高密度螺旋等离子体中，使用双光子激光诱导的荧光可以直接测量基态原子氢密度的消耗。消耗与等离子压力变得越来越高于中性气体填充压力有关。空间分辨的测量结果表明，放电室中心的氢原子耗竭。与在较低等离子体密度下的典型两步衰减相比，临时分辨的测量结果显示，在较高等离子体密度下，等离子体余辉中的原子氢得到了补充。