Magnetic Field Line Escape: Comparison with Mean Free Path

Magnetic Field Line Escape: Comparison with Mean Free Path

In the present work, we determine the fraction of magnetic field lines that reach the tokamak wall leaving the plasma surrounded by a chaotic layer created by resonant perturbations at the plasma edge. The chaotic layer arises in a scenario where an integrable magnetic field with reversed magnetic shear is perturbed by an ergodic magnetic limiter. For each considered line, we calculate its conn...

Efficient generation of a magnetic field-free line.

PURPOSE Signal encoding in magnetic particle imaging (MPI) is achieved by moving a field-free point (FFP) through the region of interest. One way to increase the sensitivity of the method is to scan the region of interest with a field-free line (FFL) instead of the FFP. Recently, the first feasible FFL coil setup was introduced. The purpose of this article is to improve the efficiency of the FF...

Electron mean free path in elemental metals

The electron mean free path k and carrier relaxation time s of the twenty most conductive elemental metals are determined by numerical integration over the Fermi surface obtained from first-principles, using constant k or s approximations and wave-vector dependent Fermi velocities vf (k). The average vf deviates considerably from the free-electron prediction, even for elements with spherical Fe...

Reconstruction of Solar Coronal Linear Force-Free Magnetic Field

Shielding of resonant magnetic perturbations in the long mean-free path regime

Abstract The effect of diamagnetic drifts and of long electron mean free path on the shielding of resonant magnetic perturbations by plasma rotation is investigated. The nature of the force exerted on a moving plasma by a resonant perturbation is qualitatively altered by both drift and long meanfree-path effects. The force is found to have three minima, each of which is a possible locus for dis...