Collisionless Plasmoid Instability
In this work, we study the collisionless plasmoid instability in reconnecting current sheets with a strong guide field. The main goal is to identify the conditions under which a collisionless sheet becomes unstable and breaks into plasmoids, and to determine how finite-\(\beta_e\) and electron-scale effects modify this threshold. Current-sheet structure and scaling of the collisionless plasmoid instability. The results show that plasmoid formation can occur in thinner sheets than in the collisional regime, and that finite-\(\beta_e\) effects further modify the critical aspect ratio for breakup.Using fluid, gyrofluid, and gyrokinetic approaches, this work shows how collisionless effects control current-sheet stability and the onset of plasmoid-mediated reconnection.
