【摘要】 通过对射频激励激光器放电电压、电流以及相位的精确测量,基于射频放电等离子体等效电路,得出等离子体总电阻(包括等离子体总电阻和鞘层电阻分量),经非线性最小平方拟合分别得到等离子体电阻和鞘层电阻,进而定量地得到等离子体和鞘层功率消耗,鞘层电压以及鞘层厚度随放电电流变化的关系,借此可以诊断出射频放电处于α或γ放电。研究表明在中等气压氦气中随着气体压强的增加和电流的增加,气体的放电模式将从α放电为主转向γ放电为主。更多还原

【Abstract】 A novel technique has been developed to evaluate the power dissipation in both plasma bulk and sheaths regions of the copper ion laser at rf discharge excitation. First, the discharge current, voltage and phase, measured with high precision, were used to determine the various impedance of interest by means of its equivalent circuit and the best-least-square data fitting. Next, power dissipation in both the plasma bulk and sheath regions can be calculated. Fimally, dependence of sheath voltage and thickness on discharge current can be studied and used to characterize the discharge modes:α or γ discharge.The results show that at a moderate helium pressure, the dominant a discharge mode changes into 7 mode, as the discharge current and helium pressure increase.更多还原