title: Fluid echoes in a pure electron plasma.
abstract: Experimental observations of diocotron wave echoes on a magnetized electron column are reported, representing Kelvin wave echoes on a rotating near-ideal fluid. The echoes occur by reversal of an inviscid wave damping process, and the phase-space mixing and unmixing are directly imaged. The basic echo characteristics agree with a simple nonlinear ballistic theory. At late times, the echo is degraded, and the maximal observed echo times agree with a theory of electron-electron collisions acting on separately evolving velocity classes.
authors.affiliation: Physics Department and Institute for Pure and Applied Physical Sciences, University of California at San Diego, La Jolla, California 92093, USA.
authors.forename: J H
authors.initials: JH
authors.lastname: Yu
authors.forename: T M
authors.initials: TM
authors.lastname: O'Neil
authors.forename: C F
authors.initials: CF
authors.lastname: Driscoll