Design and Use of an Els\"{a}sser Probe for Projection of Alfv\'{e}n Wave Fields According to Wave Direction

Measurement of plasma transport using probes usually requires simultaneous measurement of multiple quantities from which transport can be inferred. Particle and energy transport have received the most attention. We have designed and built a new probe to simultaneously measure fluctuating $E$ and $B$ fields in order to evaluate wave Poynting flux for application to Alfv\'{e}n wave experiments in the Large Plasma Device (LAPD) at UCLA. This new probe allows projection of measured wave fields onto Els\"{a}sser variables $Z^{\pm }$\equiv (\textit{E $\times $ B}$_{0})$/$\vert B_{0}\vert ^{2}\pm $ $B/$(4\textit{$\rho $}$_{0}$\textit{$\pi $})$^{0.5}$ where the time averaged background field $B_{0}$ and plasma mass density \textit{$\rho $}$_{0}$ are measured separately. Experiments were conducted in a singly ionized He-H plasma in the LAPD and these measurements are presented. The results were compared with existing measurement techniques for this type of plasma in the LAPD [1]. Findings will be discussed at the conference.\\[4pt] [1] C. A. Kletzing, D. J. Thuecks, F. Skiff, S. R. Bounds, and S. Vincena, Phys. Rev. Lett. \textbf{104}, 095001 (2010).