The time-resolved measurements of the plasma parameters are carried out in a pulse-modulated low pressure capacitively coupled discharge operated in argon and argon–oxygen mixtures. Measurements are performed at a constant radio-frequency (RF) power of 130 W at 13.56 MHz, with the pulse repetition frequency of 1 kHz and 50% duty cycle. A single RF compensated Langmuir probe, synchronized with the modulated signal, is used to investigate the effects of filling gas pressure and O₂ content in the discharge on the temporal evolution of electron density n_e, electron temperature T_e, plasma potential V_p, and electron energy probability function (EEPF). n_e shows a rapid increase with time during the start of the pulse-on phase, followed by a gradual increase to attain a steady state value. During the pulse-off phase, n_e decreases gradually. n_e drops at a higher pressure and with increasing O₂ content in the discharge. The temporal variations in T_e and V_p, on the other hand, are more abrupt than the temporal variation in n_e during the rise and the fall of the pulse. Both T_e and V_p show an increase with rising pressure and with increasing O₂ content in the discharge. The investigation of the temporal evolution of the EEPF reveals that the discharge is in a highly non-equilibrium state at the start of the pulse and evolves from bi-Maxwellian to Maxwellian distribution with the passage of time. The density of low energy electrons decreases, while the density of high energy electrons increases with increasing pressure and O₂ content in the discharge. Moreover, several peaks and broadening in the EEPF profile are also noted with increasing O₂ content.

中文翻译：

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脉冲调制电容耦合Ar / O2混合放电中等离子体参数的时间演变

血浆参数的时间分辨测量是在氩气和氩氧混合物中进行的脉冲调制低压电容耦合放电中进行的。在13.56 MHz的130 W恒定射频（RF）功率下进行测量，脉冲重复频率为1 kHz，占空比为50％。补偿朗缪尔探针的单个RF，与所述调制信号同步的，用于研究填充气体压力和O的影响₂在放电上电子密度的时间演变内容Ñ _ë，电子温度Ť _ë，等离子体电位V _p，和电子能量概率函数（EEPF）。ñ_e显示在脉冲接通阶段开始时随时间的快速增加，随后逐渐增加以达到稳态值。在脉冲关闭阶段， n _e逐渐减小。n _e在较高压力下下降，并随着放电中O ₂含量的增加而下降。另一方面，在脉冲的上升和下降期间， T _e和V _p的时间变化比n _e的时间变化更突然。既Ť _Ë和V _p示出了具有上升的压力，并随着ö增加₂放电中的含量。对EEPF的时间演变的研究表明，放电在脉冲开始时处于高度非平衡状态，并且随着时间的流逝从双麦克斯韦分布演变为麦克斯韦分布。低能电子的密度降低，而高能电子的密度随着压力和放电中O ₂含量的增加而增加。此外，随着O ₂含量的增加，还注意到了EEPF曲线中的几个峰和变宽。