Particle deconfinement in a bent magnetic mirror

Abstract

Coils misalignment in a magnetic mirror can produce additional particle transport.The magnetic field non axi-symmetry is responsible for radial and longitudinal drifts in a way much similar to the neo-classical transport in a tandem mirror cell distorted by end plugs. Accordingly, a regime exhibiting large radial displacements -similar to the resonant regime in tandem mirrors -can be obtained by confining ions azimuthally, for example by means of a properly tuned radial electric field. Because of the mass dependence of the magnetic field non-homogeneity drift velocities, the azimuthal trapping is mass specific, allowing in principle the filtering of a specific species based on its mass.1

Strategies for advantageous differential transport of ions in magnetic fusion devices

“…This region is marked by dots. The inset figure shows spatial profiles corresponding to a choice of αH = −1.6, which falls in this region; it can be seen that the 11 B is twice as peaked relative to its edge density as the 4 He. r = 0, while fusion byproducts or other contaminants are comparatively less concentrated in the interior.…”

“…The diffusive transport of plasma across a magnetic field is a subject of longstanding importance throughout plasma physics. From tokamaks [1] and stellarators [2] to magnetic mirrors [3,4] and low-temperature plasmas [5][6][7], problems related to cross-field transport are prominent both for their intrinsic scientific significance and for their practical implications in the design and analysis of plasma-based technology. The transport properties of high-Z I impurities is of particular interest in fusion plasmas, where heavier elements from the wall can reduce the performance of a fusion device.…”

A new frontier in laboratory physics: magnetized electron–positron plasmas

“…Placing the target off axis also results in improved positron confinement – by up to a factor of three – due to the increased physical space for the particle trajectories. Protons, which will eventually exit the laser target and the scattering foil, may be separated by canting the mirror, as such bent mirrors have been shown to separate particles by mass (Gueroult & Fisch 2012). The target could also be placed outside the mirror, and one of the mirror coils could be used as a magnetic lens to transport the pairs into the mirror, focusing at a scattering thin foil to mix up the phase space and trap the pair plasma.…”

“…scattering foil, may be separated by canting the mirror, as such bent mirrors have been shown to separate particles by mass (Gueroult & Fisch 2012). The target could also be placed outside the mirror, and one of the mirror coils could be used as a magnetic lens to transport the pairs into the mirror, focusing at a scattering thin foil to mix up the phase space and trap the pair plasma.…”

Finite-Difference Multiple Fluid Solution for Source-Driven Rotation in Highly Magnetized Linear Plasma Device

“…Cylindrical plasma geometry is used in fusion applications such as mirrors 1,2 , z-pinches, MagLIF [3][4][5][6] , and in some centrifugal fusion concepts [7][8][9][10][11] . They are also used for mass separation [12][13][14][15][16][17][18][19][20] .…”