【摘要】 为研究大气压射频辉光放电过程中不同工作气体(氦气和氩气)对发生器等效阻抗的影响,基于等离子体的介电特性,建立了描述等离子体区域的"电阻-电容混联"等效电路模型;通过实验测量放电电压及电流,并基于等效电路模型来计算等离子体在放电过程中的电子数密度,从而得到等离子体发生器的等效阻抗。实验测量了大气压射频辉光放电的放电电压及电流,并基于等效电路模型得到了等离子体发生器的等效阻抗及放电区的电子数密度。实验结果表明:对氦气和氩气放电,在α放电模式下其电阻及电抗的绝对值均随着放电电流的增加而减小,而电子数密度则随放电电流的增大而线性增加;且在相同的放电电流条件下,氩等离子体的电阻和电容都比氦等离子体高。研究结论可作为等离子体在不同工作气体条件下放电阻抗匹配研究的参考。更多还原

【Abstract】 A method for studying the influences of plasma working-gas compositions(helium and argon)on the impedance of the atmospheric radio-frequency glow discharges is presented.According to the dielectric properties of plasmas,an equivalent circuit model of resistance-capacitance serial-parallel-connection is proposed to describe the plasma region.The root-mean-square(rms) values of the discharge current and voltage are measured by using an oscilloscope with a current probe and a high voltage probe.The electron number density,as well as the impedance of the generator,during the discharge process is obtained based on the equivalent circuit model.The experimental measurements show that,for the α-mode helium and argon discharges,the resistance and the absolute value of the reactance of the plasmas decrease with increasing in the discharge current,while the electron number density increases almost linearly with the increase of the discharge current.The resistance and the capacitance of the argon plasmas are higher than those of the helium plasmas at the same discharge current.These results will provide guidance for the impedance matching of the discharges using different plasma working-gases.更多还原