大气压氩气刷形等离子体羽的特性研究  

Discharge characteristics of argon brush plasma plume operated at atmospheric pressure

作　　者：杨丽君[1] 宋彩虹 赵娜[1] 周帅 武珈存 贾鹏英[1] Yang Li-Jun;Song Cai-Hong;Zhao Na;Zhou Shuai;Wu Jia-Cun;Jia Peng-Ying(College of Physics Science and Technology,Hebei University,Baoding 071002,China)

机构地区：[1]河北大学物理科学与技术学院,保定071002

出　　处：《物理学报》2021年第15期193-200,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11875121,11575050,51977057);河北省自然科学基金(批准号:A2019201100,A2020201025);河北省研究生创新基金(批准号:CXZZSS2020006)资助的课题.

摘　　要：大气压非平衡低温等离子体在生物医学和表面处理等方面具有广泛的应用前景,引起研究者的关注.等离子体射流是产生大气压非平衡等离子体的重要方式,但通常产生的等离子体羽尺度较小.针对于此,本文采用一个具有三电极的介质阻挡放电装置,在交流电压与负偏置电压的共同作用下,在流动氩气的下游产生了大尺度刷状等离子体羽(50.0 mm×40.0 mm).结果表明,随着交流电压峰值的增加,等离子体羽的亮度增大.通过快速影像,研究发现视觉均匀的等离子体羽是由分叉流光的时间叠加构成的.电压和发光信号波形表明交流电压的每个周期放电一次,且放电出现于外加电压的正半周期.随着交流电压峰值的增加,分叉流光的分叉数量增多,导致放电脉冲的持续时间增加且脉冲强度增强.利用光谱仪测量了300-850 nm的发射光谱,发现谱线包括308.0 nm处的OH(A2∑_(0)^(+)-X2∏),N2(C^(3)∏u-B^(3)∏g)的第二正带系,Ar I(4p-4s)以及844.6 nm处的O I(3p3 P-3s3S).基于发射光谱,研究了分子振动温度及谱线强度比随实验参数的变化关系.结果表明,电子温度、分子振动温度和电子密度具有相似的变化趋势.利用光化线强度比的方法,研究了等离子体羽中氧原子浓度随实验参数的变化.结果表明氧原子浓度沿气流方向先增加后降低,随工作气体中氧气含量的增加先增加后降低.此外,氧原子浓度随交流电压峰值的增大而增加,并对氧原子浓度的变化进行了定性的解释.Atmospheric pressure non-equilibrium low-temperature plasma has been widely used in biomedicine,surface treatment and other fields,which has attracted the attention of researchers extensively.As one of the important methods to generate such a plasma,the plasma jet has become a popular method,which can generate a remote plasma plume at the nozzle through introducing a rare gas flow.However,plasma plume has a small diameter,which results in deficiency for the large-scale surface treatment.A dielectric barrier discharge device with three electrodes is utilized to produce a large brush-shaped plasma plume(50.0 mm×40.0 mm)downstream of flowing argon under the combined excitation of an alternate current(AC)voltage and a negative bias voltage,thereby increasing the plume scale.The results show that the luminescence intensity of the plasma plume increases with AC peak voltage increasing.By fast photography implemented with an intensified charge coupled device(ICCD),it is found that the plasma plume is composed of temporally superposed branched-streamers.The ICCD images also reveal that the number of branches increases with AC peak voltage increasing.Moreover,the waveforms of AC voltage and light emission signal recorded simultaneously indicate that the plasma plume initiates once per AC voltage cycle,which occurs in the positive half cycle of the applied voltage.With AC peak voltage increasing,the duration and intensity of discharge pulse increase,which results from more branches of the branched streamer.Besides,optical emission spectrum in a range from 300 nm to 850 nm mainly includes OH(A2∑_(0)^(+)-X2∏) peaked at 308.0 nm,the second positive system of N2(C^(3)∏u-B^(3)∏g),Ar I(4p-4s),and O I(3p3 P-3s3 S)at 844.6 nm.Based on the optical emission spectrum,the plasma parameters such as vibrational temperature and intensity ratio of spectral lines(correlated with electron density and electron temperature)are investigated.Besides,the variation of concentration of oxygen atoms in the plasma plume with experimental pa

关 键 词：等离子体射流 分叉流光 发射光谱 光化线强度 

分 类 号：O53[理学—等离子体物理]