等离子体放电中的滞后、分岔和多次上跳现象

HYSTERESIS BIFURCATION AND MULTILEVEL JUMP IN A PLASMA DISCHARGE

滞后现象很早就在放电管的伏安曲线上被发现。近年来的研究发现,这种非线性现象存在于多种等离子体放电过程中并伴随着一些不稳定性出现,Knorr利用简单的突变模型对这种现象作了定性的描述。王海达等改进了Knorr的简单模型,以便对他们观察到的三稳现象作唯象的解释。我们在实验中仔细观察了放电伏安特性随气压的变化,发现随着气压的升高,伏安特性逐渐由单稳过渡到简单的滞后,随机分岔、然后再演变成二次上跳、三次三跳。

Hysteresis and bifurcation in the I-V characterstic and their dependence on the pressure are observed in a device which contains a steady plasma with surface magnetic field.It is found that the simple sudden jump model by Knorr is suitable only in the pressure range of 1.3×10-2-1.3×10-1Pa.Above this pressure,bifurcation or multilevel jump appears in the characteristic.