Constraints on an empirical equation for asymmetry-induced transport.

Previous work on asymmetry-induced transport in a modified Malmberg–Penning trap showed that the radial particle flux was empirically constrained to be of the form Γ(ε)=-(B0/B)1.33D(ε)[∇n0+f(ε)], where ε=ω-lωR, ωR(r)=vθ/r is the column rotation frequency, ω and l are the asymmetry frequency and azimuthal mode number, ∇n0 is the radial density gradient, B is the magnetic field, B0 is an empirical constant, and D(ε) and f(ε) are unknown functions. In this paper, it is shown that further constraints can be placed upon D(ε) and f(ε) by comparing data near the ε=0 points to a first order expansion of Γ(ε). It is shown that dD/dε(0)≠0, in contradiction to resonant particle theory, and that f(ε) can only be a fraction of the size predicted by that theory. Finally, it is shown that dD/dε(0) exhibits a power-law scaling with radius, magnetic field, and the bias of the center conductor of the trap. [ABSTRACT FROM AUTHOR]