Paul trap experiment to simulate intense nonneutral beam propagation through a periodic focusing field configuration

This paper describes the design concept for a compact Paul trap experimental configuration that fully simulates the collective processes and nonlinear transverse dynamics of an intense charged particle beam that propagates over large distances through a periodic quadrupole magnetic field. To summarize, a long nonneutral plasma column (L ≫ r_p) is confined axially by applied DC voltages V ̂ = const. on end cylinders at z = ±L, and transverse confinement is provided by segmented cylindrical electrodes (at radius r_w) with applied oscillatory voltages ±V₀(t) over 90° segments. Because the transverse focusing force is similar in waveform to that produced by a discrete set of periodic quadrupole magnets in a frame moving with the beam, the Paul trap configuration offers the possibility of simulating intense beam propagation in a compact experimental facility. The nominal operating parameters in the experimental design are: barium ions (A = 137); plasma column length 2L = 2 m; wall radius r_w = 10 cm; plasma radius r_p = 1 cm; maximum wall voltage V̂₀ = 400 V; end electrode voltage up to V̂ = 500 V; and voltage oscillation frequency f₀ = 1/T = 60 kHz.