TY - JOUR
T1 - Thermodynamic Phase Transition in Magnetic Reconnection
AU - Jara-Almonte, J.
AU - Ji, H.
N1 - Funding Information:
The authors gratefully acknowledge funding from both the General Plasma Science Program from the U.S. Department of Energy’s (DOE’s) Office of Fusion Energy Sciences and the Max Planck Princeton Center for Plasma Physics under DOE Contract No. DE-AC02-09CH11466. The simulations presented in this Letter were performed on computational resources managed and supported by Princeton Research Computing, which is a consortium of groups including the Princeton Institute for Computational Science and Engineering and the Office of Information Technology’s High Performance Computing Center and Visualization Laboratory at Princeton University.
Publisher Copyright:
© 2021 American Physical Society.
PY - 2021/7/30
Y1 - 2021/7/30
N2 - By examining the entropy production in fully kinetic simulations of collisional plasmas, it is shown that the transition from collisional Sweet-Parker reconnection to collisionless Hall reconnection may be viewed as a thermodynamic phase transition. The phase transition occurs when the reconnection electric field satisfies E=EDme/mi, where me/mi is the electron-to-ion mass ratio and ED is the Dreicer electric field. This condition applies for all mi/me, including mi/me=1, where the Hall regime vanishes and a direct phase transition from the collisional to the kinetic regime occurs. In the limit me/mi→0, this condition is equivalent to there being a critical electron temperature Te≈miωi2δ2, where ωi is the ion cyclotron frequency and δ is the current sheet half-thickness. The heat capacity of the current sheet changes discontinuously across the phase transition, and a critical power law is identified in an effective heat capacity. A model for the time-dependent evolution of an isolated current sheet in the collisional regime is derived.
AB - By examining the entropy production in fully kinetic simulations of collisional plasmas, it is shown that the transition from collisional Sweet-Parker reconnection to collisionless Hall reconnection may be viewed as a thermodynamic phase transition. The phase transition occurs when the reconnection electric field satisfies E=EDme/mi, where me/mi is the electron-to-ion mass ratio and ED is the Dreicer electric field. This condition applies for all mi/me, including mi/me=1, where the Hall regime vanishes and a direct phase transition from the collisional to the kinetic regime occurs. In the limit me/mi→0, this condition is equivalent to there being a critical electron temperature Te≈miωi2δ2, where ωi is the ion cyclotron frequency and δ is the current sheet half-thickness. The heat capacity of the current sheet changes discontinuously across the phase transition, and a critical power law is identified in an effective heat capacity. A model for the time-dependent evolution of an isolated current sheet in the collisional regime is derived.
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U2 - 10.1103/PhysRevLett.127.055102
DO - 10.1103/PhysRevLett.127.055102
M3 - Article
C2 - 34397253
AN - SCOPUS:85112663076
SN - 0031-9007
VL - 127
JO - Physical review letters
JF - Physical review letters
IS - 5
M1 - 055102
ER -