Design and fabrication of a duoplasmatron extraction geometry and LEBT for the LANSCE H⁺ RFQ project.

The 750-keV H(+) Cockcroft-Walton at LANSCE will be replaced with a recently fabricated 4-rod Radio Frequency Quadrupole (RFQ) with injection energy of 35 keV. The existing duoplasmatron source extraction optics need to be modified to produce up to 35 mA of H(+) current with an emittance <0.02 π-cm-mrad (rms, norm) for injection into the RFQ.

Experimental optimization of beam quality extracted from a duoplasmatron proton ion source.

The LANSCE accelerator facility operates with two independent ion injectors for H(+) and H(-) particle beams. The H(+) ion beam is formed using a duoplasmatron source followed by a 750 keV Cockroft-Walton accelerating column. Formation of an optimal plasma meniscus is an important feature for minimizing beam emittance, and maximizing beam brightness.