Can Electron Phase-Space Holes Help a Spacecraft Locate its Position in the Geometry of Guide-Field Reconnection

Measured reconnection-associated events frequently occur during spacecraft crossings into the exhaust. Very often such separatrix crossings are accompanied by measured bipolar electrostatic fields which are interpreted as electron phase space holes. Implicit PIC guide-field reconnection simulations are used to study the properties of and relationships between electrostatic instabilities, bipolar fields, and phase-space particle distributions at different times and in different locations in the vicinity of the separatrix. The speed of bipolar structures or the phase velocity of related waves may serve as indicators of associated e-i (Buneman) instabilities or e-e (electron-two-stream) instabilities at different spatial locations. Electron phase space is used to help identify the instability and to distinguish trapped electron holes from linearly growing waves. One object is to determine signatures which can help identify whether the crossing is close to or far from the diffusion region.status: publishe