HR: 08:45h
AN: SH51D-03    [Abstracts]
TI: Role of electrostatic fields in space and astrophysical systems.
AU: * Lapenta, G
EM: lapenta@lanl.gov
AF: LANL, C305, Los Alamos, 87544 United States
AB: An unsuspected agent is emerging as a key player in a number of processes relevant to space, solar and astrophysical systems: electrostatic fields. We focus here on two processes that are present both in space and laboratory plasmas. First, we consider the formation and properties of current sheets. Current sheets are key enablers for large scale system evolution: often large scale processes lead to the formation of thin sheets where small scale processes couple with larger scales. Our recent work proposes that small scales instabilities can produce electrostatic fields on large scales with profound effects on the evolution of the system where the sheet is present. In particular, their effect can lead to the onset of reconnection. Second, a recent discovery suggests that electrostatic fields can affect the evolution of confined plasmas in laboratory experiments [2] suggesting that electrostatic fields can be a major player in magnetic dynamo processes. Our work suggests that similar processes can be also at play in space and astrophysical plasmas. We report a number of simulations that put forward a new possibility: that electrostatic fields can be a major player in processes where magnetic field energy is created (dynamo) or destroyed (reconnection). [1] W. Daughton, G. Lapenta, P. Ricci, Phys. Rev. Lett., 93, 105004, 2004 [2] D. Bonfiglio, S. Cappello, D. F. Escande, Phys. Rev. Lett., 94, 145001, 2005
DE: 7524 Magnetic fields
DE: 7526 Magnetic reconnection (2723, 7835)
SC: SPA-Solar and Heliospheric Physics [SH]
MN: Fall Meeting 2005