1Laboratory of Plasma Physics and Interdisciplinary Research (LPPRI), Department of Physics, Faculty of Science and Technology, Cheikh Anta Diop University of Dakar (UCAD)
2Laboratory of Solar Energy, Materials and Systems, Department of Physics, Faculty of Science and Technology, Cheikh Anta Diop University of Dakar (UCAD)
International Journal of Physics.
2026,
Vol. 14 No. 4, 77-85
DOI: 10.12691/ijp-14-4-1
Copyright © 2026 Science and Education PublishingCite this paper: Said Mouigni Abdallah, Ibrahima Gueye Faye, Mamadou Coulibaly, Louis Gomis, Clément Diatta, Amadou Diao. Electromagnetic Electron Density Fluctuations and β Parameter Fluctuations at the Edge of the JET Tokamak: Kinetic Effects of Pressure Anisotropy with Bi-Maxwellian Distribution.
International Journal of Physics. 2026; 14(4):77-85. doi: 10.12691/ijp-14-4-1.
Correspondence to: Said Mouigni Abdallah, Laboratory of Plasma Physics and Interdisciplinary Research (LPPRI), Department of Physics, Faculty of Science and Technology, Cheikh Anta Diop University of Dakar (UCAD). Email:
Saidmouigni.abdallah@ucad.edu.snAbstract
This work examines the effect of electron pressure anisotropy on electromagnetic density fluctuations and the MHD stability parameter at the JET tokamak edge in the kinetic limit . Using a bi‑Maxwellian equilibrium and solving the linearized gyrokinetic Vlasov equation, we derive via the Fried‑Conte function. Accounting for density and magnetic field fluctuations yields. A critical anisotropy threshold is found. For (cases), the response is Landau‑damped () and ranges from 0.048% (weak turbulence,) to 4.370% (average turbulence,), staying below the 5% MHD ballooning threshold. The case gives the lowest fluctuations. For , becomes negative, signalling a kinetic mirror instability. In average turbulence, , exceeding the MHD threshold and indicating a pre‑ELM state. Comparison with Li‑BES measurements (Réfy et al. 2018) confirms moderate‑anisotropy cases, while extreme firehose () and mirror () match pre‑ELM triggering under NBI and ICRH heating, respectively.
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