Turbulence Measurements in a 100 W Hall Thruster

As well explained in the literature, the performance of Hall thrusters can be strongly influenced from several non-stationary phenomena. Firstly, finite amplitude waves and turbulent fluctuations are worthy of extensive investigations. Several measurements have shown that the turbulent fluctuations that arise during Hall thruster operation cannot be neglected when characterize and seriously affect the particle and the energy transport. In fact, this phenomena act really on the efficiency and the performance during a conventional operation. The aim of this paper is to investigate experimentally about the typical values of the turbulence parameters in a low power Hall thruster. All our experimental investigations were performed by means of a triple Langmuir probe on the 100 W laboratory-model ALTA’s HT-100). Our measurements were performed as a function of the frequency rather than the wavenumber because it is very difficult to obtain an effective characterization of spatial turbulent fluctuations in a device with dimensions of the order of magnitude of a low power Hall thruster (“Eulerian-to-Lagrangian” transformation). Using the approximation of an ergodic system, we can estimate the turbulence coefficient as in the Yoshikawa-Rose quasilinear-transport theory 1