HR: 0830h
AN: SH31A-1077    [PDF]
TI: Kinetic Simulations of Magnetic Reconnection in Plasma With Different $\beta$ Values
AU: Brackbill, J U
EM: brackbill@cybermesa.com
AF: Mathematics and Statistics, University of New Mexico, MSC03 2150, Albuquerque, NM 87131 United States
AU: * Ricci, P
EM: ricci@lanl.gov
AF: INFM and Dipartimento di Energetica, Politecnico di Torino Corso Duca degli Abruzzi 24, Torino, 10129 Italy
AU: Lapenta, G
EM: lapenta@lanl.gov
AF: LANL, MS K717, Los Alamos, NM 87545 United States
AU: Daughton, W S
EM: daughton@lanl.gov
AF: LANL, MS B259, Los Alamos, NM 87545 United States
AB: We present kinetic simulations of collisionless magnetic reconnection in Harris current sheets. We simulate plasmas with different $\beta$ values by varying the guide fields: high guide field correspond to low $\beta$. For all values of $\beta > m_e/m_i$, fast reconnection is made possible by the separation of the electron and ion dynamics in the reconnection region. The primary mechanism that relaxes the frozen-in conditions is given by the non-gyrotropic electron pressure terms for all the guide fields considered. The reconnection rate is then enhanced by the Whistler dynamics in high $\beta$ plasmas and by the Kinetic Alfv\'en Waves dynamics in lower $\beta$ plasmas. In the latter case, the ion sound radius takes the place of the ion inertial length as the length scale of interest. The guide field diminishes the reconnection rate and decreases the reconnection saturation level. The ion and electron flow pattern, acceleration, and heating are strongly influenced by the guide field. The simulations are also preliminary to a closer comparison with the results of the Reconnection Scaling eXperiment (RSX) at Los Alamos National Laboratory, which allows one to study plasmas with different $\beta$ values.
DE: 2722 Forecasting
DE: 2744 Magnetotail
DE: 2764 Plasma sheet
DE: 7835 Magnetic reconnection
DE: 7871 Waves and instabilities
SC: SPA - Solar and Heliospheric Physics [SH]
MN: 2003 Fall Meeting