Wave-particle energy exchange directly observed in a kinetic Alfvén-branch wave
نویسندگان
چکیده
Alfvén waves are fundamental plasma wave modes that permeate the universe. At small kinetic scales, they provide a critical mechanism for the transfer of energy between electromagnetic fields and charged particles. These waves are important not only in planetary magnetospheres, heliospheres and astrophysical systems but also in laboratory plasma experiments and fusion reactors. Through measurement of charged particles and electromagnetic fields with NASA's Magnetospheric Multiscale (MMS) mission, we utilize Earth's magnetosphere as a plasma physics laboratory. Here we confirm the conservative energy exchange between the electromagnetic field fluctuations and the charged particles that comprise an undamped kinetic Alfvén wave. Electrons confined between adjacent wave peaks may have contributed to saturation of damping effects via nonlinear particle trapping. The investigation of these detailed wave dynamics has been unexplored territory in experimental plasma physics and is only recently enabled by high-resolution MMS observations.
منابع مشابه
Non-local interactions between electrons and Alfvén waves on auroral field lines
The interaction of auroral electrons with kinetic Alfvén waves is complicated by the fact that the Alfvén speed above the ionosphere is strongly inhomogeneous, leading to a region often referred to as the ionospheric Alfvén resonator (IAR). For these waves, the wave-particle interaction must be treated with a non-local kinetic approach. Linear damping of these waves due to the wave-particle int...
متن کاملKinetic Theory of the Alfvén Wave Acceleration of Auroral Electrons
Recent observations have indicated that in addition to the classical “inverted-V” type electron acceleration, auroral electrons often have a field-aligned distribution that is broad in energy and sometimes shows time dispersion indicating acceleration at various altitudes up the field line. Such acceleration is not consistent with a purely electrostatic potential drop, and suggests a wave heati...
متن کاملSelf-consistent wave-particle interactions in dispersive scale long-period field-line-resonances
[1] Using 1D Vlasov drift-kinetic computer simulations, it is shown that electron trapping in long period standing shear Alfvén waves (SAWs) provides an efficient energy sink for wave energy that is much more effective than Landau damping. It is also suggested that the plasma environment of low altitude auroral-zone geomagnetic field lines is more suited to electron acceleration by inertial or ...
متن کاملEnergy exchange and wave action conservation for magnetohydrodynamic (MHD) waves in a general, slowly varying medium
Magnetohydrodynamic (MHD) waves in the solar wind and magnetosphere are propagated in a medium whose velocity is comparable to or greater than the wave velocity and which varies in both space and time. In the approximation where the scales of the time and space variation are long compared with the period and wavelength, the ray-tracing equations can be generalized and then include an additional...
متن کاملParticle in Cell-Monte Carlo Collisions of a Plasma Column Driven by Surface Wave Plasma Discharges
In this work, applicability of Particle in Cell-Monte Carlo Collisions (PIC-MCC) simulation method for better understanding of the plasma physical mechanisms and real important aspects of a plasma column driven by surface wave plasma discharges that is used in plasma antennas is examined. Via the implementation of geometry and physical parameters of the plasma column to an Object Oriented PIC-M...
متن کامل