Full f and δf gyrokinetic particle simulations of Alfvén waves and energetic particle physics. (1st March 2023)

• Record Type: Journal Article
• Authors: Lu, Zhixin; Meng, Guo; Hatzky, Roman; Hoelzl, Matthias; Lauber, Philipp
• Is Part Of: Plasma physics and controlled fusion. Volume 65:Number 3(2023)
• Publication Date: 2023-03-01
• Subjects: δf -- full f -- particle-in-cell -- Alfvén waves -- gyrokinetic simulations -- energetic particles -- tokamak plasmas; Plasma (Ionized gases) -- Periodicals; Controlled fusion -- Periodicals; 530.44
• DOI: 10.1088/1361-6587/acb010
• Languages: English
• ISSNs: 0741-3335

Abstract

Abstract: In this work, we focus on the development of the particle-in-cell scheme and its application to the studies of Alfvén waves and energetic particle (EP) physics in tokamak plasmas. The δ f and full f schemes are formulated on the same footing adopting mixed variables and the pullback scheme for electromagnetic problems. The TRIMEG-GKX code (Lu et al 2021 J. Comput. Phys. 440 110384) has been upgraded using cubic spline finite elements and full f and δ f schemes. The toroidal Alfvén eigenmode (TAE) driven by EPs has been simulated for the International Tokamak Physics activity (ITPA)-TAE case featured by a small electron skin depth ∼ 1.18 × 10 − 3 m, which is a challenging parameter regime for electromagnetic simulations, especially for the full f model. The simulation results using the δ f scheme are in good agreement with previous work. Excellent performance of the mixed variable/pullback scheme has been observed for both full f and δ f schemes. Simulations with mixed full f EPs and δ f electrons and thermal ions demonstrate the good features of this novel scheme in mitigating the noise level. The full f scheme is a natural choice for EP physics studies, which allows for large variations of EP profiles and distributions in velocity space, providing a powerful tool for kinetic studies using realistic experimental distributions related to intermittent and transient plasma activities.