Observation of weak impact of a stochastic magnetic field on fast-ion confinement

Phys Rev Lett. 2005 Sep 16;95(12):125001. doi: 10.1103/PhysRevLett.95.125001. Epub 2005 Sep 14.

Abstract

Fast ions are observed to be very well confined in the Madison Symmetric Torus reversed field pinch despite the presence of stochastic magnetic field. The fast-ion energy loss is consistent with the classical slowing down rate, and their confinement time is longer than expected by stochastic estimates. Fast-ion confinement is measured from the decay of d-d neutrons following a short pulse of a 20 keV atomic deuterium beam. Ion confinement agrees with computation of particle trajectories in the stochastic magnetic field, and is understood through consideration of ion guiding center islands.