Experimental study of the ion current to cylindrical Langmuir probe considering finite ion temperature

摘要

This work verifies experimentally the theoretical radial model, developed by the authors, when the positive ion temperature, Ti, is not negligible small compared to the electron one, Te. An experimental device controlled by a Virtual Instrument (VI) performed in LabView?, has been developed. The theoretical model is a generalization of the one developed by Allen, Boyd and Reynolds (ABR theory), and due to the positive ion thermal motion, the ion current collected by the probe is increased with respect to the case of cold ions. So, we can state that the orbital models underestimate the positive ion current collected by the probe. The measurements have been performed in the ion saturation zone of the I-V characteristic, where the perturbation originated by the probe originates in the plasma is small. A very good agreement between the theoretical and experimental ion to current characteristics has been found.