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Updated: Oct 24, 2025
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Phase Diagram Characterization Using Magnetic Beads as Liquid Carriers
Published on: September 4, 2015
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Thermodynamic Phase Transition in Magnetic Reconnection.
1Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA.
Physical Review Letters
|August 16, 2021
Summary
Plasma reconnection transitions from collisional to collisionless regimes, akin to a thermodynamic phase transition. This occurs when the reconnection electric field reaches a critical threshold dependent on electron-to-ion mass ratio.
Area of Science:
- Plasma Physics
- Thermodynamics
- Astrophysics
Background:
- Magnetic reconnection is a fundamental process in plasma physics, crucial for energy release in astrophysical phenomena.
- Existing models often simplify plasma behavior, neglecting kinetic effects or collisionality.
- Understanding the transition between different reconnection regimes is vital for accurate modeling.
Purpose of the Study:
- To investigate the transition from collisional Sweet-Parker reconnection to collisionless Hall reconnection.
- To characterize this transition as a thermodynamic phase transition.
- To derive a model for the time-dependent evolution of collisional current sheets.
Main Methods:
- Analysis of entropy production in fully kinetic simulations of collisional plasmas.
- Examination of the reconnection electric field in relation to the Dreicer electric field and electron-to-ion mass ratio.
- Investigation of critical electron temperature and heat capacity changes across the phase transition.
Main Results:
- The transition is identified as a thermodynamic phase transition occurring at a critical reconnection electric field.
- A critical electron temperature is found in the limit of vanishing electron-to-ion mass ratio.
- Discontinuous changes in current sheet heat capacity and a critical power law are observed.
Conclusions:
- The transition between collisional and collisionless reconnection regimes can be thermodynamically classified.
- The derived conditions and critical parameters provide new insights into kinetic plasma behavior.
- A model for isolated collisional current sheet evolution is established, aiding future research.
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