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Title: Study of energy conversion and partitioning in the magnetic reconnection layer of a laboratory plasma

Abstract

While 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 have also carried out a systematic study of the effects of boundary conditions on themore » 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. 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.« less

Authors:
; ; ; ; ;  [1];  [2]
  1. Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)
  2. Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
Publication Date:
OSTI Identifier:
22410415
Resource Type:
Journal Article
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 22; Journal Issue: 5; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1070-664X
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; BOUNDARY CONDITIONS; COMPUTERIZED SIMULATION; DATASETS; DIFFUSION; ELECTRIC FIELDS; ELECTRIC POTENTIAL; ENERGY CONVERSION; MAGNETIC RECONNECTION; MAGNETIZATION; MONITORING; PARTICLES; PARTITION; PLASMA

Citation Formats

Yamada, Masaaki, Yoo, Jongsoo, Jara-Almonte, Jonathan, Ji, Hantao, Kulsrud, Russell M., Myers, Clayton E., and Daughton, William. Study of energy conversion and partitioning in the magnetic reconnection layer of a laboratory plasma. United States: N. p., 2015. Web. doi:10.1063/1.4920960.
Yamada, Masaaki, Yoo, Jongsoo, Jara-Almonte, Jonathan, Ji, Hantao, Kulsrud, Russell M., Myers, Clayton E., & Daughton, William. Study of energy conversion and partitioning in the magnetic reconnection layer of a laboratory plasma. United States. https://doi.org/10.1063/1.4920960
Yamada, Masaaki, Yoo, Jongsoo, Jara-Almonte, Jonathan, Ji, Hantao, Kulsrud, Russell M., Myers, Clayton E., and Daughton, William. 2015. "Study of energy conversion and partitioning in the magnetic reconnection layer of a laboratory plasma". United States. https://doi.org/10.1063/1.4920960.
@article{osti_22410415,
title = {Study of energy conversion and partitioning in the magnetic reconnection layer of a laboratory plasma},
author = {Yamada, Masaaki and Yoo, Jongsoo and Jara-Almonte, Jonathan and Ji, Hantao and Kulsrud, Russell M. and Myers, Clayton E. and Daughton, William},
abstractNote = {While 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 have 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. 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/22410415}, journal = {Physics of Plasmas},
issn = {1070-664X},
number = 5,
volume = 22,
place = {United States},
year = {Fri May 15 00:00:00 EDT 2015},
month = {Fri May 15 00:00:00 EDT 2015}
}

Works referencing / citing this record:

Electron heating and energy inventory during asymmetric reconnection in a laboratory plasma: ASYMMETRIC RECONNECTION IN LABORATORY
journal, September 2017


Two-stage bulk electron heating in the diffusion region of anti-parallel symmetric reconnection
journal, October 2016


An experimental platform for pulsed-power driven magnetic reconnection
journal, May 2018


Perspectives on magnetic reconnection
journal, December 2016