56th Annual Meeting of the APS Division of Plasma Physics
Volume 59, Number 15
Monday–Friday, October 27–31, 2014;
New Orleans, Louisiana
Session BI2: Space, Astro, and Lab Astro
9:30 AM–12:30 PM,
Monday, October 27, 2014
Room: Bissonet
Chair: Amitava Bhattacharjee, Princeton Plasma Physics Laboratory
Abstract ID: BAPS.2014.DPP.BI2.5
Abstract: BI2.00005 : Experimental study of energy conversion in the magnetic reconnection layer*
11:30 AM–12:00 PM
Preview Abstract
Abstract
Author:
Masaaki Yamada
(Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ USA)
Magnetic reconnection, in which magnetic field lines break and reconnect to
change their topology, occurs throughout the universe: in solar flares, the
earth's magnetosphere, star forming galaxies, and laboratory fusion plasmas
[1]. The essential feature of reconnection is that it energizes plasma
particles by converting magnetic energy to particle energy; this process
both accelerates and heats the plasma particles. Despite the recent advances
of reconnection research, the exact mechanisms for bulk plasma heating,
particle acceleration, and energy flow channels remain unresolved. In this
work, the mechanisms responsible for the energization of plasma particles in
the magnetic reconnection layer are investigated in the MRX device together
with a quantitative evaluation of the conversion of magnetic energy to ions
and electrons. A comprehensive analysis of the reconnection layer is made in
terms of two-fluid physics based on the measurements of two-dimensional
profiles of 1) electric potential, 2) flow vectors of electrons and ions,
and 3) the electron temperature, T$_{e}$ and the ion temperature, T$_{i}$ in
the layer. It is experimentally verified that a saddle shaped electrostatic
electric potential profile is formed in the reconnection plane. Ions are
accelerated across the separatrices by the strong electrostatic field and
enter the exhaust region where they become thermalized [2,3]. Electron
heating is observed to extend beyond the electron diffusion region, and
non-classical heating mechanisms associated with high frequency fluctuations
is found to play a role. Our quantitative analysis of the energy transport
processes and energy inventory concludes that more than 50 {\%} of magnetic
energy is converted to plasma particles, of which 2/3 transferred to ions
and 1/3 to electrons. The results which demonstrate that conversion of
magnetic energy occurs in a significantly larger region than theoretically
considered before, are compared with the two-fluid simulations and the
recent space measurements [4]. Broader implication of the present results
will be discussed.\\[4pt]
[1] M. Yamada, R. Kulsrud, {\&} H. Ji, \textit{Rev. Mod. Phys.} \textbf{82}, 603--664 (2010).\\[0pt]
[2] J. Yoo et al, \textit{Phys. Plasmas }\textbf{21}, 055706 (2014).\\[0pt]
[3] M. Yamada et al, Submitted \textit{to Nature Communications} (2014).\\[0pt]
[4] J. P. Eastwood \textit{et al.}, \textit{Phys. Rev. Lett. }\textbf{110}, 225001 (2013).
*Supported by DOE, NASA and NSF. Collaborators; J. Yoo, J. Jara Almonte, H. Ji, R. Kulsrud, C. Myers
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2014.DPP.BI2.5