Observation of neoclassical diffusion effects on plasma losses produced by magnetic field asymmetries

Cross field loss of a partially ionized plasma induced by magnetic field asymmetries varies as the reciprocal of the collision frequency, ν, at large ν and as ν at small collision frequencies. The value of the collision frequency at peak loss ( ≈ 40 times classical for 1% field asymmetries) is a function of the asymmetry amplitude and wavelength. These observations can be accounted for in terms of an ambipolar neoclassical diffusion model taking into account field asymmetries in a shearless multipole-like device.