A beam of accelerated ions (111) is produced from a quiescent plasma (19) created by diffusing a heated primary plasma (15) through an accelerator/homogenizer structure (17) having a uniform voltage potential VB and a total surface area ARF. The RF-conductive, dielectric coated surfaces of the accelerator/homogenizer structure are quasi-uniformly dispersed throughout the primary plasma. The quiescent plasma has a generally homogenous preselected plasma potential VPA approximately equal to VB. An RF-grounded structure (112) having a total ground surface area AG, wherein ARF>AG, attracts ions from the quiescent plasma to produce the accelerated ion beam.