An Experimental Study of the Cylindrical Langmuir Probe Response in the Transition Regime

摘要

Experiments were performed in a highly expanded low density flowing argon plasma using both single and double probes. Results are obtained in the near free-molecule regime over a wide range of ratios of Debye length to probe radius, probe length to probe radius, and probe radius to relevant mean free path. The effect of collisions on the ion-saturation current, the retarding field electron current, the floating potential and the inferred electron temperature was investigated experimentally. An existing approximate analysis describing the collisional single probe ion-saturation current and the retarding field electron current was extended to describe the collisional double probe characteristic and magnitude of the single probe floating potential. (Author)