Medusa 2 is a new helicon machine designed and built by

Prof. F.F. Chen and Ph.D. student H. Torreblanca.

It uses permanent magnets to produce the magnetic field and

a novel transmission line to carry the cooling water and RF power to the antennas.

Each tube has been optimized to give the highest density. 

The tubes can be placed in an array so that the plasma is uniform beneath them. 

The array can be compact to give higher density, or staggered, as shown here,

to cover large areas for web-coating of moving substrates.

In a compact configuration, the source can produce argon densities >5x10¹¹ cm^-3

with 3kW of 13.56 MHz power per 8 tubes, and uniformity to +/- 2% at somewhat

lower density.  The components have been hardened for commercial use

in etching or deposition on large substrates.