【摘要】 大气压射频辉光放电的不稳定性是限制其应用的主要原因,脉冲调制射频技术有助于提高放电稳定性.通过试验诊断放电电学特性,进一步研究了大气压脉冲调制射频辉光放电中脉冲调制参数对放电稳定性的影响.当固定调制脉冲频率而降低占空比时,特别是当射频放电段工作在起辉阶段时,α放电模式的电压和电流范围都增加;当射频频率提高时也有助于增加射频放电工作在α模式的电流范围.在试验中固定电压幅值,研究射频频率在5、10和15 MHz时α-γ放电模式转变随占空比的变化,验证了在低占空比下可以获得更稳定的α模式放电,另外在氦气中掺入1.5%氮气的情况下获得了脉冲调制射频辉光放电稳定工作在α模式.研究结果表明,通过调制脉冲参数可以控制大气压脉冲调制射频辉光放电的稳定性.更多还原

【Abstract】 The discharge instability of radio-frequency(RF)atmospheric pressure glow discharges(APGDs)limits their potential applications,which can be improved by the pulse modulation on radiofrequency excitation.The electrical characteristics of discharge are investigated experimentally on the characteristics of modulation pulses in terms of frequency and duty cycle.The ranges of voltage and current inα discharge mode are expanded by reducing the duty cycle with fixed frequency,especially when the RF discharge burst operates in the ignition phase.The ranges of current inαdischarge mode are also expanded with elevated radio frequency.Furtherly,the improvement of discharge stability with reduced duty cycle is confirmed experimentally byα-γ mode transition with fixed voltage and radio frequency of 5,10 and 15 MHz.The stable operation ofα discharge mode is achieved with the introduction of 1.5% nitrogen in helium in pulse modulated RF atmospheric pressure glow discharges.Research results show that the discharge stability of RF discharge can be improved by manipulating the characteristics of modulation pulses.更多还原