Operation Mode on Pulse Modulation in Atmospheric Radio Frequency Glow Discharges

Abstract

The discharge operation regime of pulse modulated atmospheric radio frequency (RF) glow discharge in helium is investigated on the duty cycle and frequency of modulation pulses. The characteristics of radio frequency discharge burst in terms of breakdown voltage, alpha(α)gamma(γ) mode transition voltage and current are demonstrated by the discharge current voltage characteristics. The minimum breakdown voltage of RF discharge burst was obtained at the duty cycle of 20% and frequency of 400 kHz, respectively. The α-γ mode transition of RF discharge burst occurs at higher voltage and current by reducing the duty cycle and elevating the modulation frequency before the RF discharge burst evolving into the ignition phase, in which the RF discharge burst can operate stably in the γ mode. It proposes that the intensity and stability of RF discharge burst can be improved by manipulating the duty cycle and modulation frequency in pulse modulated atmospheric RF glow discharge.

Numerical study on peak current in pulse-modulated radio-frequency discharges with atmospheric helium–oxygen admixtures

“…The value of the PCFP is 10.1 A cm −2 , which is 11.1% greater than those in the rest periods only of 9.1 A cm −2 during the power-on phase. In the rest of the rf periods, the PCFP will not be observed, which shows a different discharge pattern from the usual pulse-modulated rf discharges with the excitation frequency of 13.56 MHz [16,43,44].…”

Treatment uniformity of atmospheric pressure plasma on flexible and porous material surface: A critical review

“…数值模拟和实验研究发现, 通过脉冲调制射频 辉光放电与常压脉冲放电相互作用, 在常压脉冲调 制射频辉光放电"关闭"段引入高压脉冲放电, 利用 高压脉冲放电中产生的等离子体活性粒子(特别是 电子)对射频放电的作用, 有效地降低了射频辉光 放电的起辉和维持电压 [33,37] . 图4(a)是脉冲调制 射频放电和引入高压脉冲后的放电电流-电压特性 曲线, 射频频率为10.2 MHz, 脉冲调制射频功率的 占空比是50%, 调制频率为10 kHz [35] . 两条曲线中电 [34] .…”

“…70, No. 9 (2021) 099401 099401-5 图4(b)和图4(c)分别是在高压脉冲信号关 闭40和10 µs延时处, 引入脉冲调制射频放电后, 起辉阶段的空间结构分布随时间的变化 [35] . 拍摄 的等离子体图像曝光时间为100 ns, 每100 ns拍 摄一张, 触发的零时刻是高压脉冲放电被触发的时 刻.…”

“…4. (a) Current voltage characteristics of RF discharge burst with (dash) and without (solid) pulsed discharge in pulse modulated RF APGD; temporal evolution of discharge spatial profile during discharge burst ignition with the time interval between pulsed discharge and RF discharge burst of (b) 40 and (c) 10 µs[35] .…”

On peak current in atmospheric pulse-modulated microwave discharges by the PIC-MCC model

“…The rf discharges could be effectively optimized by pulse modulation. By providing pulsed power, the rf plasmas are only generated during the power-on phase to avoid serious gas heating, thus the α-γ mode transition will be delayed [16,17].…”