title: Anomalous Heating and Plasmoid Formation in a Driven Magnetic Reconnection Experiment.
abstract: We present a detailed study of magnetic reconnection in a quasi-two-dimensional pulsed-power driven laboratory experiment. Oppositely directed magnetic fields (B=3  T), advected by supersonic, sub-Alfvénic carbon plasma flows (V_{in}=50  km/s), are brought together and mutually annihilate inside a thin current layer (δ=0.6  mm). Temporally and spatially resolved optical diagnostics, including interferometry, Faraday rotation imaging, and Thomson scattering, allow us to determine the structure and dynamics of this layer, the nature of the inflows and outflows, and the detailed energy partition during the reconnection process. We measure high electron and ion temperatures (T_{e}=100  eV, T_{i}=600  eV), far in excess of what can be attributed to classical (Spitzer) resistive and viscous dissipation. We observe the repeated formation and ejection of plasmoids, consistent with the predictions from semicollisional plasmoid theory.
authors.affiliation: Blackett Laboratory, Imperial College, London, SW7 2AZ, United Kingdom.
authors.forename: J D
authors.initials: JD
authors.lastname: Hare
authors.affiliation: Blackett Laboratory, Imperial College, London, SW7 2AZ, United Kingdom.
authors.forename: L
authors.initials: L
authors.lastname: Suttle
authors.affiliation: Blackett Laboratory, Imperial College, London, SW7 2AZ, United Kingdom.
authors.forename: S V
authors.initials: SV
authors.lastname: Lebedev
authors.affiliation: Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge Massachusetts 02139, USA.
authors.forename: N F
authors.initials: NF
authors.lastname: Loureiro
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, Observatoire de Paris, PSL Research University, CNRS, UMR 8112, LERMA F-75005, Paris, France.
authors.forename: A
authors.initials: A
authors.lastname: Ciardi
authors.affiliation: Blackett Laboratory, Imperial College, London, SW7 2AZ, United Kingdom.
authors.forename: G C
authors.initials: GC
authors.lastname: Burdiak
authors.affiliation: Blackett Laboratory, Imperial College, London, SW7 2AZ, United Kingdom.
authors.forename: J P
authors.initials: JP
authors.lastname: Chittenden
authors.affiliation: Blackett Laboratory, Imperial College, London, SW7 2AZ, United Kingdom.
authors.forename: T
authors.initials: T
authors.lastname: Clayson
authors.affiliation: Blackett Laboratory, Imperial College, London, SW7 2AZ, United Kingdom.
authors.forename: C
authors.initials: C
authors.lastname: Garcia
authors.affiliation: Blackett Laboratory, Imperial College, London, SW7 2AZ, United Kingdom.
authors.forename: N
authors.initials: N
authors.lastname: Niasse
authors.affiliation: Blackett Laboratory, Imperial College, London, SW7 2AZ, United Kingdom.
authors.forename: T
authors.initials: T
authors.lastname: Robinson
authors.affiliation: Blackett Laboratory, Imperial College, London, SW7 2AZ, United Kingdom.
authors.forename: R A
authors.initials: RA
authors.lastname: Smith
authors.affiliation: Blackett Laboratory, Imperial College, London, SW7 2AZ, United Kingdom.
authors.forename: N
authors.initials: N
authors.lastname: Stuart
authors.affiliation: Blackett Laboratory, Imperial College, London, SW7 2AZ, United Kingdom.
authors.forename: F
authors.initials: F
authors.lastname: Suzuki-Vidal
authors.affiliation: Blackett Laboratory, Imperial College, London, SW7 2AZ, United Kingdom.
authors.forename: G F
authors.initials: GF
authors.lastname: Swadling
authors.affiliation: Northwest Institute of Nuclear Technology, Xi'an 710024, China.
authors.forename: J
authors.initials: J
authors.lastname: Ma
authors.affiliation: Xi'an Jiaotong University, Shaanxi 710049, China.
authors.forename: J
authors.initials: J
authors.lastname: Wu
authors.affiliation: Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Yang