Ion heating due to Alfven waves in a helicon plasma

Summary form only given. Recent models for ion heating in the fast solar wind region of the Sun predicts the heating is due to MHD turbulence driven by counter propagating, low-frequency Alfven waves. Experiments to test this theory is conducted in the West Virginia University HELIX (Hot Helicon Experiment) device in helium plasma. Densities in HELIX are on the order of 10/sup 13/ cm/sup -3/ with ion temperatures of about 0.3 eV. To create counter propagating Alfven waves one of two techniques are employed. We first attempt to launch the Alfven waves from the helicon source region and generate a reflection due to an Alfven speed gradient. The HELIX device has an Alfven speed profile similar to the solar corona, a short region of increased Alfven speed followed by a rapid decrease in speed as the magnetic field expands. Should the first method prove to be unsuccessful, two waves are launched at each other from different antennas. This method has the added advantage of allowing the relative intensities of the counter-propagating waves to be varied. Temperatures of helium ions are measured using a RF compensated energy analyzer. We present information on the experimental apparatus as well as preliminary data.