High beta ion driven microinstabilities in the large experiment on instabilities and anisotropies

Summary form only given, as follows. Construction of the West Virginia University (WVU) Large Experiment on Instabilities and Anisotropies (LEIA) is now complete. LEIA is designed to investigate a wide variety of high beta, space relevant plasma phenomena. Of particular interest are electromagnetic instabilities driven by the free energy associated with non-isotropic ion distributions, i.e., different parallel and perpendicular ion temperatures. These instabilities occur at plasma betas (/spl beta/=8/spl pi/kT/B/sup 2/) of order unity and ion temperature anisotropies, perpendicular divided by parallel, over the range 0.25 to 4.0. The plasma for LEIA is generated with a steady-state helicon plasma source. By varying the source magnetic field and the magnetic field in LEIA, the ion temperature anisotropy in LEIA can be controlled. Initial measurements of the magnetic fluctuation spectra as a function of plasma parameters, e.g., plasma beta and ion temperature anisotropy, will be presented.