Design and use of an Elsasser probe for analysis of Alfven wave fields according to wave direction

We have designed an electric and magnetic field probe which simultaneously measure both quantities in the directions perpendicular to the background magnetic field for application to Alfven wave experiments in the Large Plasma Device at UCLA. This new probe allows for the projection of measured wave fields onto generalized Elsasser variables. Experiments were conducted in a singly ionized He plasma at 1850 G in which propagation of Alfven waves was observed using this new probe. We demonstrate that a clear separation of transmitted and reflected signals and determination of Poynting flux and Elsasser variables can be achieved. (C) 2011 American Institute of Physics. [doi:10.1063/1.3649950]