RT Conference Proceedings
T1 Current-Voltage and floating-potential characteristics of cylindrical emissive probes from a full-kinetic model based on the orbital motion theory
A1 Chen, Xin
A1 Sánchez Arriaga, Gonzalo
AB To model the sheath structure around an emissive probe with cylindrical geometry, the Orbital-Motion theory takes advantage of three conserved quantities (distribution function, transverse energy, and angular momentum) to transform the stationary Vlasov-Poisson system into a single integro-differential equation. For a stationary collisionless unmagnetized plasma, this equation describes self-consistently the probe characteristics. By solving such an equation numerically, parametric analyses for the current-voltage (IV) and floating-potential (FP) characteristics can be performed, which show that: (a) for strong emission, the space-charge effects increase with probe radius; (b) the probe can float at a positive potential relative to the plasma; (c) a smaller probe radius is preferred for the FP method to determine the plasma potential; (d) the work function of the emitting material and the plasma-ion properties do not influence the reliability of the floating-potential method. Analytical analysis demonstrates that the inflection point of an IV curve for non-emitting probes occurs at the plasma potential. The flat potential is not a self-consistent solution for emissive probes.
PB IOP Publishing
SN 1742-6588
YR 2017
FD 2017-09
LK https://hdl.handle.net/10016/28506
UL https://hdl.handle.net/10016/28506
LA eng
NO 12th International Workshop on Electric Probes in Magnetized Plasmas (IWEP 2017)
NO This work was supported by the Ministerio de Economía y Competitividad of Spain (Grant NoESP-2016-75887). Work by G. Snchez-Arriaga was supported by the Ministerio de Economía y Competitividad of Spain (Grant No RYC-2014-15357).
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