Electron Trapping by Lower Hybrid Drift Waves During Guide-Field Magnetic Reconnection

Wave-particle interaction in plasma mediate the transfer of energy and momentum from large scale drivers such as magnetic reconnection to kinetic scales where dissipation occurs, resulting in bulk heating and particle acceleration. In this study, we investigate nonlinear wave-particle interactions during guide-field magnetic reconnection in the PHAse Space MApping (PHASMA) experiment. In the separatrix region, measurements reveal electron velocity distribution functions (EVDFs) with pronounced non-Maxwellian features. During reconnection these beam-like structures appear at velocities that match the phase speed of locally measured lower hybrid drift waves (LHDWs), v_ph=w/k . The LHDWs are observed with a linear Langmuir probe array and four-tip fluctuation probes. Analysis of the EVDF shows oscillatory structures consistent with nonlinear trapping of electrons in the wave potential. Supporting test-particle simulations reproduce key features of the EVDF measurements, confirming that resonant wave-particle coupling leads to localized energy exchange and enhanced particle acceleration.