High-current four-beam xenon ion source for heavy-ion fusion

The growing interest in inertial confinement fusion using heavy ions has elicited from the Los Alamos Scientific Laboratory a proposal to use a multi-channel radio-frequency quadrupole (RFQ) structure for the initial stage of the heavy-ion accelerator. The RFQ would have 4 channels in each module and each channel would accelerate 25 mA of Xe+1. Based on experiments with xenon beam production with a high current duoPIGatron source at Chalk River Nuclear Laboratories, a 245 keV 4-beam xenon injector has been designed for this 4-channel RFQ. The injector is of modular design with 4 small independent plasma sources mounted in a 10 cm square array on a common combined extraction and acceleration column. The electrodes have 4 separate sets of apertures and each channel produces a 29 mA beam for injection into its corresponding RFQ channel. This paper presents a conceptual design for the injector, code calculations for the column electrode design and results of a preliminary test carried out to verify the feasibility of the concept