Saturation of the electron cyclotron drift instability and its transport
In plain words
The leading suspect for the fast electron leakage is a short-wavelength wave driven by the electrons' sideways drift. Whether this wave alone, once it stops growing, carries the observed electron current is not settled.
Precise statement
The electron cyclotron drift instability (ECDI, driven by the E x B electron drift relative to unmagnetized ions, wavelengths about 0.1 cm) is widely proposed as the transport source. Determine its nonlinear saturation amplitude and the anomalous electron current it carries in 3D with realistic geometry, ion mass, secondary emission and wall boundaries, and whether it alone accounts for measured mobility. An answer is converged 3D particle-in-cell results compared with collective Thomson scattering data.
What would settle it
Converged 3D kinetic simulations whose ECDI spectra and transport match laser-scattering measurements in an operating thruster.
Status in the literature
Unverified note
Long 1D simulations reported nonlinear suppression of the ECDI-driven current in 2025 (arXiv:2503.03015), at odds with earlier results.