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⪢rp) is confined axially by applied DC voltages V̂=const. on end cylinders at z=±L, and transverse confinement is provided by segmented cylindrical electrodes (at radius rw) 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 rw=10 cm; plasma radius rp=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.