摘要
通过比较研究,讨论了尘埃粒子的存在对等离子体衰减特性的影响。主要讨论了三种情况下的衰减系数:1)仅考虑粒子间的碰撞;2)考虑粒子间的碰撞以及电子、离子对尘埃粒子的充电;3)在2)的基础上考虑背景等离子体电势的影响。在推导出衰减系数的基础上,选取火箭喷焰为典型实例,详细给出了衰减系数随温度、压强以及频率变化趋势。研究结果表明:在微波段低频区时,温度、压强皆有临界值,使得对应的衰减系数变化产生低谷。当温度、压强一定时,尘埃等离子体的衰减系数峰值出现在共振频率附近,峰值与共振频率之间的距离取决于温度、压强对共振频率的影响;温度、压强、频率相同时,计算三种情况下的衰减系数,第三种的总是大于前两种的,且所得衰减系数正好处在实测范围内。所以,在计算衰减系数时需要考虑背景等离子体电势的影响。
The effect of dust particles on the attenuation characteristic of plasma is discussed in three kinds of situation： 1） considering the collision between particles only; 2） considering both the particles＇ collision and the charging of the charged particles （electrons and ions） on the dust particle; 3） considering the effect of the electrical potential based on 2）. Based on the calculation of the attenuation coefficient, the rocket exhaust plume is taken as an example on further analysis and discussion. The attenuation coefficient has a critical value with temperature and pressure, when in the low frequency of microwave band, and the corresponding attenuation coefficient produces a trough. The attenuation peaks appears near the dusty plasma resonant frequency. The distance between the position of the peak value and the resonant frequency is determined by the effect of the temperature and pressure on resonance frequency. At a given temperature, pressure and frequency, the attenuation coefficient of the third is larger than the other two and in the area of the experimental data. So, the effect of the electrical potential impact factor needs to be considered in the calculation.
出处
《激光与光电子学进展》
CSCD
北大核心
2016年第2期241-249,共9页
Laser & Optoelectronics Progress
基金
江苏省自然科学基金(BK20131428)
关键词
光谱学
尘埃等离子体
衰减系数
电势影响因子
电导率
spectroscopy
dusty plasma
attenuation coefficient
electrical potential impact factor
conductivity
