arXiv subjects

Ivan Chernoshtanov

Publications and source records attributed to Ivan Chernoshtanov.

3 recordsLinked to original sources

arXiv2026

Ion-acoustic eigenmodes in a helical magnetic mirror

Plasma rotation together with corrugation of magnetic field can result in coupling acoustic waves with different azimuthal wavenumbers and formation of eigenmodes with discrete frequency spectrum and zero longitudinal group velocity in a helical magnetic mirror. Such eigenmodes can be destabilized by plasma rotation as well as resonant interaction with trapped ions. Equations describing these waves in the linear approximation are derived and results of numerical solving the equations are discussed. Probably these eigenmodes may drive anomalous ions scattering which is needed for effective suppressing flow of rarefied plasma through a helical mirror.

physics.plasm-ph↗

arXiv2025

High-beta equilibrium in mirror machine with population of fast sloshing ions

A method of constructing the high-beta (diamagnetic-bubble-like) equilibrium with a population of fast sloshing ions is discussed. Fast ions move along betatron orbits; such ions can arise because of off-axis neutral beam injection. Conservation of the adiabatic invariant of these ions is proposed; a simplified expression for the invariant is presented. Numerical examples of equilibrium with sloshing ions are shown and conservation of the invariant is justified by a direct numerical simulation of motion of fast ions even in the case with beta equal to 1.

physics.plasm-ph↗

arXiv2020

Collisionless particle dynamic in an axi-symmetric diamagnetic trap

Particle dynamic in an axi-symmetric mirror machine with an extremely high plasma pressure equal to pressure of vacuum magnetic field (so-called regime of diamagnetic confinement) is investigated. Extrusion of magnetic field from central region due to plasma diamagnetism leads to non-conservation of the magnetic moment and can result in chaotic movement and fast losses of particles. The following mechanisms can provide particle confinement for unlimited time: absolute confinement of particles with high azimuthal velocity and conservation of adiabatic invariant for particle moving in smooth magnetic field. The criteria of particle confinement and estimations of lifetime of unconfined particles are obtained and verified in direct numerical simulation. Particle confinement time in the diamagnetic trap in regime of gas-dynamic outflow is discussed.

physics.plasm-ph↗