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. A series of experiments were performed to find the optimal combination of extraction voltage and extracted current for the H(+) beam. Measurements yielded the best ratio of beam perveance to Child-Langmuir perveance of 0.52 for maximizing beam brightness.