Date of Graduation
Eberly College of Arts and Sciences
Physics and Astronomy
The first measurements of an ion temperature anisotropy/beta inverse correlation in a high beta laboratory experiment are presented. The observation of this correlation is similar to such a correlation present in in-situ spacecraft measurements and predicted in theory. Low-frequency fluctuations are also observed. According to measurements presented here, these waves are electromagnetic, transverse, occur at frequencies below the cyclotron frequency and have wavenumbers consistent with predictions for the ion cyclotron anisotropy instability, also referred to as the Alfven Ion-Cyclotron instability. The device is a space simulation chamber that uses a helicon source for its plasma source. Ranges of ion beta and ion temperature anisotropy are 10-4 to 10-2 and 1 to 15, respectively. The correlation is experimentally determined to be T⊥/ T∥ = 1 + 0.15 b-0.5i∥ .
Keiter, Paul Arthur, "Experimental investigation of ion temperature anisotropy driven instabilities in a high beta plasma" (1999). Graduate Theses, Dissertations, and Problem Reports. 3180.