The most important feature of magnetic reconnection is that it energizes plasma particles by converting magnetic energy to particle energy, the exact mechanisms by which this happens are yet to be determined despite a long history of reconnection research. Recently, we have reported our results on the energy conversion and partitioning in a laboratory reconnection layer in a short communication [Yamada et al., Nat. Commun. 5, 4474 (2014)]. The present paper is a detailed elaboration of this report together with an additional dataset with different boundary sizes. Our experimental study of the reconnection layer is carried out in the two-fluid physics regime where ions and electrons move quite differently. We have observed that the conversion of magnetic energy occurs across a region significantly larger than the narrow electron diffusion region. A saddle shaped electrostatic potential profile exists in the reconnection plane, and ions are accelerated by the resulting electric field at the separatrices. These accelerated ions are then thermalized by re-magnetization in the downstream region. A quantitative inventory of the converted energy is presented in a reconnection layer with a well-defined, variable boundary. We also carried out a systematic study of the effects of boundary conditions on the energy inventory. This study concludes that about 50% of the inflowing magnetic energy is converted to particle energy, 2/3 of which is ultimately transferred to ions and 1/3 to electrons. When assisted by another set of magnetic reconnection experiment data and numerical simulations with different sizes of monitoring box, it is also observed that the observed features of energy conversion and partitioning do not depend on the size of monitoring boundary across the range of sizes tested from 1.5 to 4 ion skin depths.
Yamada, Masaaki, et al. "Study of energy conversion and partitioning in the magnetic reconnection layer of a laboratory plasma." Physics of Plasmas, vol. 22, no. 5, May. 2015. https://doi.org/10.1063/1.4920960
Yamada, Masaaki, Yoo, Jongsoo, Jara-Almonte, Jonathan, Daughton, William, Ji, Hantao, Kulsrud, Russell M., & Myers, Clayton E. (2015). Study of energy conversion and partitioning in the magnetic reconnection layer of a laboratory plasma. Physics of Plasmas, 22(5). https://doi.org/10.1063/1.4920960
Yamada, Masaaki, Yoo, Jongsoo, Jara-Almonte, Jonathan, et al., "Study of energy conversion and partitioning in the magnetic reconnection layer of a laboratory plasma," Physics of Plasmas 22, no. 5 (2015), https://doi.org/10.1063/1.4920960
@article{osti_1254743,
author = {Yamada, Masaaki and Yoo, Jongsoo and Jara-Almonte, Jonathan and Daughton, William and Ji, Hantao and Kulsrud, Russell M. and Myers, Clayton E.},
title = {Study of energy conversion and partitioning in the magnetic reconnection layer of a laboratory plasma},
annote = {The most important feature of magnetic reconnection is that it energizes plasma particles by converting magnetic energy to particle energy, the exact mechanisms by which this happens are yet to be determined despite a long history of reconnection research. Recently, we have reported our results on the energy conversion and partitioning in a laboratory reconnection layer in a short communication [Yamada et al., Nat. Commun. 5, 4474 (2014)]. The present paper is a detailed elaboration of this report together with an additional dataset with different boundary sizes. Our experimental study of the reconnection layer is carried out in the two-fluid physics regime where ions and electrons move quite differently. We have observed that the conversion of magnetic energy occurs across a region significantly larger than the narrow electron diffusion region. A saddle shaped electrostatic potential profile exists in the reconnection plane, and ions are accelerated by the resulting electric field at the separatrices. These accelerated ions are then thermalized by re-magnetization in the downstream region. A quantitative inventory of the converted energy is presented in a reconnection layer with a well-defined, variable boundary. We also carried out a systematic study of the effects of boundary conditions on the energy inventory. This study concludes that about 50% of the inflowing magnetic energy is converted to particle energy, 2/3 of which is ultimately transferred to ions and 1/3 to electrons. When assisted by another set of magnetic reconnection experiment data and numerical simulations with different sizes of monitoring box, it is also observed that the observed features of energy conversion and partitioning do not depend on the size of monitoring boundary across the range of sizes tested from 1.5 to 4 ion skin depths.},
doi = {10.1063/1.4920960},
url = {https://www.osti.gov/biblio/1254743},
journal = {Physics of Plasmas},
issn = {ISSN 1070-664X},
number = {5},
volume = {22},
place = {United States},
publisher = {American Institute of Physics (AIP)},
year = {2015},
month = {05}}
MODERN CHALLENGES IN NONLINEAR PLASMA PHYSICS: A Festschrift Honoring the Career of Dennis Papadopoulos, AIP Conference Proceedingshttps://doi.org/10.1063/1.3544319