%AShi, Peiyun%AShi, Peiyun [Department of Physics and Astronomy and the Center for KINETIC Plasma Physics, West Virginia University, Morgantown, West Virginia 26506, USA]%ASrivastav, Prabhakar%ASrivastav, Prabhakar [Department of Physics and Astronomy and the Center for KINETIC Plasma Physics, West Virginia University, Morgantown, West Virginia 26506, USA]%ABarbhuiya, M.%ABarbhuiya, M. [Department of Physics and Astronomy and the Center for KINETIC Plasma Physics, West Virginia University, Morgantown, West Virginia 26506, USA]%ACassak, Paul%ACassak, Paul [Department of Physics and Astronomy and the Center for KINETIC Plasma Physics, West Virginia University, Morgantown, West Virginia 26506, USA]%AScime, Earl [Department of Physics and Astronomy and the Center for KINETIC Plasma Physics, West Virginia University, Morgantown, West Virginia 26506, USA]%AScime, Earl%ASwisdak, M. [Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742, USA]%ASwisdak, M.%ABeatty, Cuyler%ABeatty, Cuyler [Department of Physics and Astronomy and the Center for KINETIC Plasma Physics, West Virginia University, Morgantown, West Virginia 26506, USA]%AGilbert, Tyler%AGilbert, Tyler [Department of Physics and Astronomy and the Center for KINETIC Plasma Physics, West Virginia University, Morgantown, West Virginia 26506, USA]%AJohn, Regis%AJohn, Regis [Department of Physics and Astronomy and the Center for KINETIC Plasma Physics, West Virginia University, Morgantown, West Virginia 26506, USA]%ALazo, Matthew [Department of Physics and Astronomy and the Center for KINETIC Plasma Physics, West Virginia University, Morgantown, West Virginia 26506, USA]%ALazo, Matthew%ANirwan, Ripudaman%ANirwan, Ripudaman [Department of Physics and Astronomy and the Center for KINETIC Plasma Physics, West Virginia University, Morgantown, West Virginia 26506, USA]%APaul, Mitchell [Department of Physics and Astronomy and the Center for KINETIC Plasma Physics, West Virginia University, Morgantown, West Virginia 26506, USA]%APaul, Mitchell%AScime, Ethan [Department of Physics and Astronomy and the Center for KINETIC Plasma Physics, West Virginia University, Morgantown, West Virginia 26506, USA]%AScime, Ethan%AStevenson, Katey%AStevenson, Katey [Department of Physics and Astronomy and the Center for KINETIC Plasma Physics, West Virginia University, Morgantown, West Virginia 26506, USA]%ASteinberger, Thomas [Department of Physics and Astronomy and the Center for KINETIC Plasma Physics, West Virginia University, Morgantown, West Virginia 26506, USA]%ASteinberger, Thomas%BJournal Name: Physics of Plasmas; Journal Volume: 29; Journal Issue: 3; Related Information: CHORUS Timestamp: 2023-08-10 08:08:56 %D2022%IAmerican Institute of Physics %JJournal Name: Physics of Plasmas; Journal Volume: 29; Journal Issue: 3; Related Information: CHORUS Timestamp: 2023-08-10 08:08:56 %K %MOSTI ID: 10363359 %PMedium: X %TElectron-only reconnection and associated electron heating and acceleration in PHASMA %X

Using incoherent Thomson scattering, electron heating and acceleration at the electron velocity distribution function (EVDF) level are investigated during electron-only reconnection in the PHAse Space MApping (PHASMA) facility. Reconnection arises during the merger of two kink-free flux ropes. Both push and pull type reconnection occur in a single discharge. Electron heating is localized around the separatrix, and the electron temperature increases continuously along the separatrix with distance from the X-line. The local measured gain in enthalpy flux is up to 70% of the incoming Poynting flux. Notably, non-Maxwellian EVDFs comprised of a warm bulk population and a cold beam are directly measured during the electron-only reconnection. The electron beam velocity is comparable to, and scales with, electron Alfvén speed, revealing the signature of electron acceleration caused by electron-only reconnection. The observation of oppositely directed electron beams on either side of the X-point provides “smoking-gun” evidence of the occurrence of electron-only reconnection in PHASMA. 2D particle-in-cell simulations agree well with the laboratory measurements. The measured conversion of Poynting flux into electron enthalpy is consistent with recent observations of electron-only reconnection in the magnetosheath [Phan et al., Nature 557, 202 (2018)] at similar dimensionless parameters as in the experiments. The laboratory measurements go beyond the magnetosheath observations by directly resolving the electron temperature gain.

%0Journal Article