Helicon discharges have extensively been studied for over 25 years both because of their intriguing physics and because of their utility in producing high plasma densities for industrial applications. Almost all measurements so far have been made away from the antenna region in the plasma ejected into a chamber where there may be a strong magnetic field (B-field) but where the radiofrequency (R...

The finite element method (FEM) has the potential of simulating plasma waves seamlessly from the core to the vacuum and antenna regions. We explored the possibility of using a versatile FEM solver package, COMSOL, for lower hybrid (LH) wave simulation. Special care was paid to boundary conditions to satisfy toroidal symmetry. The non-trivial issue of introducing hot plasma effects was addressed...

A large-area planar spiral antenna has been installed on the linear laboratory device VINETA. For low radio-frequency (RF ) powers the induction coil is operated in the inductive discharge mode with typical plasma densities of n ≈ 1 · 10 m and electron temperatures of Te ≈ 5 eV. At higher RFpowers a transition to the helicon wave sustained discharge mode is observed, in which the density increa...

Rf-driven ion sources for accelerators and many industrial applications benefit from detailed numerical modeling and simulation of plasma characteristics. For instance, modeling of the Spallation Neutron Source (SNS) internal antenna H(-) source has indicated that a large plasma velocity is induced near bends in the antenna where structural failures are often observed. This could lead to improv...

Neutral depletion effects are observed in a steady-state flowing argon helicon plasma with a magnetic nozzle for high rf input powers up to 3 kW . Noninvasive diagnostics including 105 GHz microwave interferometry and optical spectroscopy with collisional-radiative modeling are used to measure the electron density ne , electron temperature Te , and neutral density nn . A region of weak neutral ...

in this paper, a novel directional super wide band micro strip antenna based on a simple and new geometry has been proposed. the antenna exhibits the widest bandwidth ever reported to the authors’ knowledge from 50 ghz to 200 ghz. its radiation pattern is approximately steady in the frequency ranges of 50 ghz to 200 ghz. the antenna consists of a club-like radiating patch, a combination of thre...

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