One of the limitations in studying dusty plasmas is that many of the important properties of the dust (like the charge) are directly coupled to the surrounding plasma conditions rather than being determined independently. The application of high-intensity ultraviolet (UV) sources to generate discharging photoelectric currents may provide an avenue for developing methods of controlling dust charge. Careful selection of the parameters of the UV source and dust material may even allow for this to be accomplished with minimal perturbation of the background plasma. The Auburn Magnetized Plasma Research Laboratory (MPRL) has developed a ‘proof-of-concept’ experiment for this controlled photo-discharging of dust; a high-intensity, near-UV source was used to produce large changes in the equilibrium positions of lanthanum hexaboride ( $\textrm {LaB}_6$ ) particles suspended in an argon DC glow discharge with negligible changes in the potential, density and temperature profiles of the background plasma. The shifts in equilibrium position of the dust are consistent with a reduction in dust charge. Video analysis is used to quantify the changes in position, velocity and acceleration of a test particle under the influence of the UV and Langmuir probes are used to measure the effects on the plasma.

中文翻译：

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复杂等离子体中尘埃的可控光放电

研究尘埃等离子体的限制之一是尘埃的许多重要特性（如电荷）与周围的等离子体条件直接相关，而不是独立确定。应用高强度紫外线 (UV) 源产生放电光电流可为开发控制粉尘电荷的方法提供途径。仔细选择 UV 源和灰尘材料的参数甚至可以在对背景等离子体的干扰最小的情况下实现这一点。奥本磁化等离子体研究实验室 (MPRL) 为这种受控的尘埃光放电开发了一个“概念验证”实验；使用高强度近紫外光源使六硼化镧的平衡位置发生很大变化（ $\textrm {实验室}_6$ ) 悬浮在氩直流辉光放电中的粒子，背景等离子体的电势、密度和温度分布变化可忽略不计。灰尘平衡位置的变化与灰尘电荷的减少一致。视频分析用于量化测试粒子在紫外线影响下的位置、速度和加速度的变化，朗缪尔探针用于测量对等离子体的影响。