Quantitative Study Of Guide Field Effects on Hall Reconnection In A Laboratory Plasma

Tharp, T. D.; Yamada, M.; Ji, H.; Lawrence, E.; Dorfman, S.; Myers, C.; Yoo, J.

doi:10.2172/1063118

Cited by 7 publications

(8 citation statements)

References 4 publications

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“…Although the current study extends our knowledge on plasma energization during reconnection, it does not cover reconnection with a guide field. Reconnection with a guide field shows different profiles of the Hall fields [ Tharp et al , ] as well as the density profile [ Fox et al , ], which means that processes of plasma energization are different during reconnection with a significant guide field. Plasma energization during guide field reconnection is a potential future research topic.…”

Section: Discussionmentioning

confidence: 99%

Electron heating and energy inventory during asymmetric reconnection in a laboratory plasma

Yoo

Jara-Almonte

et al. 2017

JGR Space Physics

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Electron heating and the energy inventory during asymmetric reconnection are studied in the laboratory plasma with a density ratio of about 8 across the current sheet. Features of asymmetric reconnection such as the large density gradients near the low‐density side separatrices, asymmetric in‐plane electric field, and bipolar out‐of‐plane magnetic field are observed. Unlike the symmetric case, electrons are also heated near the low‐density side separatrices. The measured parallel electric field may explain the observed electron heating. Although large fluctuations driven by lower hybrid drift instabilities are also observed near the low‐density side separatrices, laboratory measurements and numerical simulations reported here suggest that they do not play a major role in electron energization. The average electron temperature increase in the exhaust region is proportional to the incoming magnetic energy per an electron/ion pair but exceeds scalings of the previous space observations. This discrepancy is explained by differences in the boundary condition and system size. The profile of electron energy gain from the electric field shows that there is additional electron energy gain associated with the electron diamagnetic current besides a large energy gain near the X line. This additional energy gain increases electron enthalpy, not the electron temperature. Finally, a quantitative analysis of the energy inventory during asymmetric reconnection is conducted. Unlike the symmetric case where the ion energy gain is about twice more than the electron energy gain, electrons and ions obtain a similar amount of energy during asymmetric reconnection.

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Section: Discussionmentioning

confidence: 99%

Electron heating and energy inventory during asymmetric reconnection in a laboratory plasma

Yoo

Jara-Almonte

et al. 2017

JGR Space Physics

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“…It is hypothesized that the minimal impact of the modification of electron flows on the reconnection rate is due to the reconnection process being strongly externally driven, as the small net fractional change in electron velocity DV e,net t0.1V e from the increase in V e on one side and decrease on the other side is negligible in comparison with the large inflow speeds (DV e;net ( V b ). Interestingly, these results bear on collisionless guide-field reconnection in strongly driven systems, where small perturbations in the local physics due to out-of-plane fields may be overwhelmed by the strong drive mechanism, in contrast to tenuous, low-b, quasi-steady plasmas 39 .…”

Section: Laser-driven Asymmetric Magnetic Reconnection Experimentsmentioning

confidence: 90%

A laboratory study of asymmetric magnetic reconnection in strongly driven plasmas

Rosenberg

Fox

et al. 2015

Nat Commun

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Magnetic reconnection, the annihilation and rearrangement of magnetic fields in a plasma, is a universal phenomenon that frequently occurs when plasmas carrying oppositely directed field lines collide. In most natural circumstances, the collision is asymmetric (the two plasmas having different properties), but laboratory research to date has been limited to symmetric configurations. In addition, the regime of strongly driven magnetic reconnection, where the ram pressure of the plasma dominates the magnetic pressure, as in several astrophysical environments, has also received little experimental attention. Thus, we have designed the experiments to probe reconnection in asymmetric, strongly driven, laser-generated plasmas. Here we show that, in this strongly driven system, the rate of magnetic flux annihilation is dictated by the relative flow velocities of the opposing plasmas and is insensitive to initial asymmetries. In addition, out-of-plane magnetic fields that arise from asymmetries in the three-dimensional plasma geometry have minimal impact on the reconnection rate, due to the strong flows.

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“…B y is increased by ∼ 0.01 in the area extending from the EDR to the IDR where B 2D y ∼ 0.04 (taken at x = 1.6d i and y = 1.5 in the 2D reconnection), or ∼ 25% enhancement in 3D than in 2D. The enhancement of B y is asymmetric around the x-point-this is due to the Hall-effect which generates an asymmetric quadratic electron current density in guide field magnetic reconnection 19,30 .…”

Section: How Does Anomalous Resistivity Accelerate Magnetic Reconnmentioning

confidence: 99%

How anomalous resistivity accelerates magnetic reconnection

Che

2017

Physics of Plasmas

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Quantitative Study Of Guide Field Effects on Hall Reconnection In A Laboratory Plasma

Cited by 7 publications

References 4 publications

Electron heating and energy inventory during asymmetric reconnection in a laboratory plasma

Electron heating and energy inventory during asymmetric reconnection in a laboratory plasma

A laboratory study of asymmetric magnetic reconnection in strongly driven plasmas

How anomalous resistivity accelerates magnetic reconnection

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