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We present the overview of a new experimental apparatus that has been developed to create a single flux rope for studying magnetized plasma jet dynamics, with a focus on the roles of Magnetohydrodynamic instabilities in magnetic reconnection and ion heating. The plasma is generated using coplanar electrodes with a single gas nozzle to create a single flux rope, high-voltage capacitor banks, gas puff valves, and a background magnetic field coil. This setup enables controlled exploration of various plasma stability regimes by adjusting external parameters. A comprehensive suite of diagnostic tools—including a He–Ne interferometer, ion Doppler spectroscopy, and a magnetic field probe array—has been implemented to measure key plasma parameters such as density, temperature, and magnetic field. Initial findings indicate that the apparatus can create a single flux rope and sustain it as a stable jet, a kink-unstable jet, and pinched plasma. In particular, kink instability results in significant ion heating, suggesting that magnetic reconnection may be driven by kink instability. These findings provide valuable insights into plasma dynamics relevant to space physics and magnetized inertial fusion, where fluid instabilities and magnetic reconnection are frequently observed.
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Electron and Proton Energization in 3D Reconnecting Current Sheets in Semirelativistic Plasma with Guide Magnetic Field
Abstract Using 3D particle-in-cell simulation, we characterize energy conversion, as a function of guide magnetic field, in a thin current sheet in semirelativistic plasma, with relativistic electrons and subrelativistic protons. There, magnetic reconnection, the drift-kink instability (DKI), and the flux-rope kink instability all compete and interact in their nonlinear stages to convert magnetic energy to plasma energy. We compare fully 3D simulations with 2D in two different planes to isolate reconnection and DKI effects. In zero guide field, these processes yield distinct energy conversion signatures: ions gain more energy than electrons in 2Dxy(reconnection), while the opposite is true in 2Dyz(DKI), and the 3D result falls in between. The flux-rope instability, which occurs only in 3D, allows more magnetic energy to be released than in 2D, but the rate of energy conversion in 3D tends to be lower. Increasing the guide magnetic field strongly suppresses DKI, and in all cases slows and reduces the overall amount of energy conversion; it also favors electron energization through a process by which energy is first stored in the motional electric field of flux ropes before energizing particles. Understanding the evolution of the energy partition thus provides insight into the role of various plasma processes, and is important for modeling radiation from astrophysical sources such as accreting black holes and their jets.
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- Award ID(s):
- 1903335
- PAR ID:
- 10496861
- Publisher / Repository:
- DOI PREFIX: 10.3847
- Date Published:
- Journal Name:
- The Astrophysical Journal Letters
- Volume:
- 964
- Issue:
- 2
- ISSN:
- 2041-8205
- Format(s):
- Medium: X Size: Article No. L21
- Size(s):
- Article No. L21
- Sponsoring Org:
- National Science Foundation
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