Effect of Guide Field Strength and Ion Mass on Reconnection Layer Width in Electron-Only Reconnection

Electron-only reconnection refers to a regime of magnetic reconnection in which electron dynamics dominate the reconnection process, and ions remain largely uncoupled from the reconnecting magnetic field. In this regime, the reconnection layer that forms around the X-point is typically on the order of the electron inertial length. The layer width plays a crucial role in determining the reconnection rate. In these experiments, we examine the influence of external parameters-such as guide field strength and ion mass-on the width of the reconnection layer in a laboratory plasma. We employ the PHase Space MApping Experiment (PHASMA), a linear plasma device specializing in resolving electron-scale dynamics, to investigate how the reconnection layer width varies with applied guide field and ion species.