Yaglom law for electrostatic turbulence in laboratory magnetized plasmas

It has recently been shown that a Yaglom law for electrostatic turbulence, that is, arelation for the third-order mixed moment involving the particle number density as a passive scalarand the E × B drift velocity, can be deduced from a simple model of electrostatic fluctuations,which describes bursty turbulence in plasmas. In this letter, the existence of the Yaglom law forelectrostatic turbulence in laboratory magnetized plasmas is reported for the first time. Usingmeasurements of intermittent transport at the edge of the RFX-mod reversed field pinch plasmadevice, we found that the above scaling relation is nicely verified at intermediate scales of fewcentimeters. In this range of scales, that unambiguously represents the inertial range of electrostaticturbulence, we also analyze the intermittency properties of electrostatic turbulence by measuringanomalous scaling exponents of density and velocity structure functions.

It has recently been shown that a Yaglom law for electrostatic turbulence, that is, a relation for the third-order mixed moment involving the particle number density as a passive scalar and the E x B drift velocity, can be deduced from a simple model of electrostatic fluctuations, which describes bursty turbulence in plasmas. In this letter, the existence of the Yaglom law for electrostatic turbulence in laboratory magnetized plasmas is reported for the first time. Using measurements of intermittent transport at the edge of the RFX-mod reversed field pinch plasma device, we found that the above scaling relation is nicely verified at intermediate scales of few centimeters. In this range of scales, that unambiguously represents the inertial range of electrostatic turbulence, we also analyze the intermittency properties of electrostatic turbulence by measuring anomalous scaling exponents of density and velocity structure functions.