title: Experimental study of ion beam optics in a two-stage accelerator.
abstract: Hydrogen ion beam optics in a two-stage linear acceleration system is studied by examining the beam divergence as a function of the voltage and gap distribution, the beam perveance, the background gas pressure, the aspect ratio, and the total accelerating energy (60-110 keV). The system consists of four electrodes with single, cylindrical, straight-bore apertures acting as an extraction-accel-decel column. An optimum relation between the field ratio and the extraction perveance is obtained from measurements for the minimum beam divergence condition. The HWHM divergence angle is <0.3 degrees under optimum conditions. Qualitative agreement between the measurements and a previous theoretical study is noticed. A potential application of the results to high energy neutral beam injectors for fusion research is also discussed.
authors.affiliation: Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA.
authors.forename: J
authors.initials: J
authors.lastname: Kim
authors.forename: W L
authors.initials: WL
authors.lastname: Gardner
authors.forename: M M
authors.initials: MM
authors.lastname: Menon