Surfatron plasma-loaded as surfaprobe: A theoretical model

Plasma columns generated and substained, within dielectric tubes, by travelling or standing, slow surface waves (Gould-Trivelpiece electromechanical modes) can be used as diagnostic probes, that we call SWP open-quotes surfaprobesclose quotes, when these are embedded in a suitable plasma. These surface wave generated plasmas are practically nonradiating in electrodeless devices and can be regarded as dielectric plasmaguides, operating also in the presence of an axial confining dc magnetic field. These plasmaguides, described in slow wave operation, were firstly presented and discussed by A.W. Trivelpiece. In this paper a quasistatic theoretical description, together with a surfaguide equivalent circuit is presented and in a first approximation discussed. We consider a SWP operating in two typical conditions, as: (1) conductivity probe in a collisional SW plasma, (2) reactivity probe in a collisionless SW plasma. In a SWP, for instance, either the matching network of the wave launcher circuitry (LC network in HF operation or reentrant cavity in UHF) or the fluctuation of eigenmodes (detected, for instance, by the light emitted by the SWP) as a diagnostic sensor may be used. We may consider, as an example, the Ro-box launcher for a SWP, claimed for over 1 MHz-10 GHz frequency range