title: A robust method for measurement of fluctuation parallel wavenumber in laboratory plasmas.
abstract: Measuring the parallel wavenumber is fundamental for the experimental characterization of electrostatic instabilities. It becomes particularly important in toroidal geometry, where spatial inhomogeneities and curvature can excite both drift instabilities, whose wavenumber parallel to the magnetic field is finite, and interchange instabilities, which typically have vanishing parallel wavenumber. We demonstrate that multipoint measurements can provide a robust method for the discrimination between the two cases.
authors.affiliation: CRPP-EPFL, Association EURATOM-Confédération Suisse, Lausanne 1015, Switzerland. f.m.poli@warwick.ac.uk
authors.forename: F M
authors.initials: FM
authors.lastname: Poli
authors.forename: M
authors.initials: M
authors.lastname: Podestà
authors.forename: A
authors.initials: A
authors.lastname: Fasoli