A low-frequency variational model for energetic particle effects in the pressure-coupling scheme

Abstract

Energetic particle effects in magnetic confinement fusion devices are commonly studied by hybrid kinetic-fluid simulation codes whose underlying continuum evolution equations often lack the correct energy balance. While two different kinetic-fluid coupling options are available (current-coupling and pressure-coupling), this paper applies the Euler-Poincaré variational approach to formulate a new conservative hybrid model in the pressure-coupling scheme. In our case the kinetics of the energetic particles are described by guiding center theory. The interplay between the Lagrangian fluid paths with phase space particle trajectories reflects an intricate variational structure which can be approached by letting the 4-dimensional guiding center trajectories evolve in the full 6-dimensional phase space. Then, the redundant perpendicular velocity is integrated out to recover a four-dimensional description. A second equivalent variational approach is also reported, which involves the use of phase space Lagrangians. Not only do these variational structures confer on the new model a correct energy balance, but also they produce a cross-helicity invariant which is lost in the other pressure-coupling schemes reported in the literature.

References in corpus (11)

• GEMPIC: Geometric ElectroMagnetic Particle-In-Cell Methods
• Hamiltonian approach to hybrid plasma models
• Variational approach to low-frequency kinetic-MHD in the current coupling scheme
• Neutral Vlasov kinetic theory of magnetized plasmas
• The Hamiltonian structure and Euler-Poincaré formulation of the Vlasov-Maxwell and gyrokinetic systems
• Variational principles for the guiding-center Vlasov-Maxwell equations
• Application of the phase space action principle to finite-size particle plasma simulations in the drift-kinetic approximation
• A Lagrangian kinetic model for collisionless magnetic reconnection
• Hamiltonian structure of the guiding center plasma model
• NIMROD calculations of energetic particle driven toroidal Alfvén eigenmodes
• From liquid crystal models to the guiding-center theory of magnetized plasmas

Cited by in corpus (4)

• Stochastic Variational Formulations of Fluid Wave-Current Interaction
• Hamiltonian kinetic-Hall Magnetohydrodynamics with fluid and kinetic ions in the current and pressure coupling schemes
• A class of three-dimensional gyroviscous magnetohydrodynamic models
• Variational mean-fluctuation splitting and drift-fluid models