Design and Construction of Helicon Plasma Source Antenna and Coils*

A helicon plasma source is being designed and constructed at the UAA Plasma Lab.  The radio frequency (RF) antenna will operate in the range 10-15 MHz, with up to 1.5 kW RF power.  The particular antenna design is chosen by exploring and modeling conventional options such as Nagoya, Boswell, and helical half wave geometries.  Hardware models of each antenna are constructed, and corresponding RF power coupling and matching network designs are tested in the lab.  A final choice of antenna design to be installed on the Pyrex cylinder housing the plasma discharge is presented, and progress toward initial discharge testing is discussed.  The magnetic field of the helicon source will be produced by 8-16 modular copper coils with a total of 2-4 kW DC power leading to axial field strength 500-1000 Gauss.  The coil design and construction progress is presented, as well as the software and hardware control and measurement environment for helicon discharge experiments.  Spectroscopy, imaging, and RF-compensated Langmuir probe diagnostics under development and construction for the first discharge experiments are discussed as well.