在大气压氩气介质阻挡放电中,首次通过跃变外加电压得到了稳定的靶波斑图.实验分别研究了跃变再缓变和直接跃变升压模式下靶波斑图的稳定性和波长选择.研究发现,跃变再缓变升压之后得到的靶波斑图不稳定,其与螺旋波相互转换.在这种转换中,靶波每次出现的时间为几十毫秒.直接跃变升压得到的靶波斑图稳定性明显增强,其稳定时间通常为5min以上.比较不同升压模式下靶波斑图的波长,发现直接跃变升压模式下波长随电压升高减小较快.综上表明,升压模式对靶波斑图的稳定性和波长都有影响.
Stable target patterns are produced by suddenly increasing the applied voltage in argon dielectric barrier discharge at atmospheric pressure for the first time.The stability and wavelength selection of target patterns obtained by gradually increasing applied voltage after suddenly increasing applied voltage and by directly suddenly increasing applied voltage are studied respectively.It is found that the target patterns obtained by gradually increasing applied voltage are unstable.There is mutual transformation between target pattern and spiral,in which the target pattern can only survive for several tens milliseconds.The target patterns obtained by directly suddenly increasing applied voltage are much more stable,which can survive for more than 5min.The wavelength selections of target patterns obtained by above two methods are studied.It is found that the wavelength of target patterns obtained by directly suddenly increasing applied voltage decreases more quickly as the applied voltage increases.The results show that the applied voltage increasing way in which the target patterns are obtained plays an important role in the stability and wavelength selection of target pattern.