Anomalous Resistivity and Electron Heating by Lower Hybrid Drift Waves during Magnetic Reconnection with a Guide Field

The lower hybrid drift wave (LHDW) has been a candidate for anomalous resistivity and electron heating inside the electron diffusion region of magnetic reconnection. In a laboratory reconnection layer with a finite guide field, quasielectrostatic LHDW (ES-LHDW) propagating along the direction nearly perpendicular to the local magnetic field is excited in the electron diffusion region. ES-LHDW generates large density fluctuations ($\delta n_e$, about 25% of the mean density) that are correlated with fluctuations in the out-of-plane electric field ($\delta E_Y$, about twice larger than the mean reconnection electric field). With a small phase difference ($\sim 30°$) between two fluctuating quantities, the anomalous resistivity associated with the observed ES-LHDW is twice larger than the classical resistivity and accounts for 20% of the mean reconnection electric field. After we verify the linear relationship between $\delta n_e$ and $\delta E_Y$, anomalous electron heating by LHDW is estimated by a quasilinear analysis. The estimated electron heating is about $2.6\pm 0.3\mathrm{MW}/m^3$, which exceeds the classical Ohmic heating of about $2.0\pm 0.2\mathrm{MW}/m^3$. This LHDW-driven heating is consistent with the observed trend of higher electron temperatures when the wave amplitude is larger. Presented results provide the first direct estimate of anomalous resistivity and electron heating power by LHDW, which demonstrates the importance of wave-particle interactions in magnetic reconnection.