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Faculty Publication: Associate Professor of Physics David Schaffner

March 18, 2022

"Measurement of the Taylor Scale in a Magnetized Turbulent Laboratory Plasma Wind-Tunnel"

Authors: Cartagena-Sanchez, C.A.; Carlson, J.M.; and Schaffner, D.A.

Source: Physics of Plasmas, Volume 29, DOI: 10.1063/5.0073207, March 2022

Type of Publication: Article in a Periodical

Abstract: The fluid Taylor scale is measured in the Bryn Mawr Experiment (BMX) of the Bryn Mawr Plasma Laboratory and examined as a potential dissipation scale of magnetic turbulence within the plasma. We present the first laboratory measurements of the Taylor scale of a turbulent magnetized plasma through multi-point correlations of broadband magnetic fluctuations. From spatial and temporal correlations, respectively, the measured Taylor scales are 2卤12卤1 and 3卤1鈥塩m3卤1鈥塩m. These measurements are on the same order of magnitude as estimated ion dissipation scales within the BMX plasma with ion inertial scales between 1鈥塧nd鈥�10鈥塩m1鈥塧nd鈥�10鈥塩m and ion gyroscales between 0.1鈥塧nd鈥�1.0鈥塩m0.1鈥塧nd鈥�1.0鈥塩m. From these measurements, a magnetic Reynolds number can be computed. Since Taylor scale values are determined using multi-point correlations and a Richardson extrapolation technique, an estimate of the magnetic Reynolds number can be found without the added complication of specifying a model of microscopic diffusivity, a parameter often difficult to obtain experimentally.

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