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Magnetic reconnection and impulsive instabilities in tokamak plasmas: Some analogies with astrophysical flares

  • Paolo BurattiEmail author
A Decade of AGILE
  • 43 Downloads
Part of the following topical collections:
  1. A Decade of AGILE: Results, Challenges and Prospects of Gamma-Ray Astrophysics

Abstract

Four kinds of tokamak plasma dynamical processes are described, which could be of interest for a comparative study with events such as solar and astrophysical flares. The first two processes are related to instabilities with different mechanism and different spatial location (violation of the Kruskal–Shafranov limit around the plasma center in one case and violation of a pressure gradient limit at the plasma edge in the other case); nevertheless, both result in similar cycles of slow accumulation and rapid release of energy. The third process is related to a kinetic instability of the electron momentum distribution: beamed electrons can destabilize plasma waves, which in turn transfer energy to electron motion perpendicular to the magnetic field, resulting in enhanced synchrotron emission. Cycles with slow accumulation and rapid release are observed here too. The fourth kind of event consists in the disruption of a current channel, during which a substantial fraction of the stored magnetic energy is transferred to a population of relativistic electrons.

Keywords

Magnetic reconnection Runaway electrons Disruption Tokamak 

Notes

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical statement

The authors declare that the manuscript has been prepared following the rules of good scientific practice.

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Copyright information

© Accademia Nazionale dei Lincei 2019

Authors and Affiliations

  1. 1.ENEA, Fusion and Nuclear Safety DepartmentC. R. FrascatiFrascatiItaly

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