Paul Trap Simulator Experiment (PTSX) to Simulate Intense Beam Propagation Through a Periodic Focusing Quadrupole Field

Abstract

The Paul Trap Simulator Experiment (PTSX) is under construction at the Princeton Plasma Physics Laboratory to simulate intense beam propagation through a periodic quadrupole magnetic field. In the Paul trap configuration, a long nonneutral plasma column is confined axially by dc voltages on end cylinders at z = +L and z = −L, and transverse confinement is provided by segmented cylindrical electrodes 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 laboratory facility. The experimental layout is described, together with the planned experiments to study beam mismatch, envelope instabilities, halo particle production, and collective wave excitations. PAUL TRAP CONFIGURATION Periodic focusing accelerators and transport systems have a wide range of applications ranging from basic scientific research in high energy and nuclear physics, to applications such as spallation neutron sources, tritium production, heavy ion fusion, and nuclear waste transmutation, to mention a few examples [1-5]. Of particular interest, at the high beam currents and charge densities of practical interest, are the combined effects of the applied focusing field and the intense self fields produced by the beam space charge and current on determining detailed equilibrium, stability, and transport properties. The purpose of this paper is to describe the Paul Trap Simulator Experiment (PTSX) under construction at the Princeton Plasma Physics Laboratory that fully simulates the collective processes and nonlinear transverse dynamics of an intense charged particle beam propagating through a periodic quadrupole magnetic field configuration. The idea of using a single-species trap to model periodically-focused beam propagation has been discussed by Davidson, et al. [6], and by Okamoto and Tanaka [7], although the emphasis of their work is on solenoidal confinement [7], whereas the present paper focuses on periodic quadrupole confinement [1-6]. The equivalence of the Paul trap configuration to intense beam propagation through a periodic focusing quadrupole field is discussed in Ref. 6, and in Secs. 2 and 3 of this paper we describe the experimental configuration, 1 Research supported by the Department of Energy and in part by the Office of Naval Research.

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Cite this paper

@inproceedings{DavidsonPaulTS, title={Paul Trap Simulator Experiment (PTSX) to Simulate Intense Beam Propagation Through a Periodic Focusing Quadrupole Field}, author={Ronald C . Davidson and Philip C. Efthimion and Erik P. Gilson and Richard Majeski and Hong Qin} }