The High Beam to Power Efficiency Investigation of Miniaturized Microwave Ion Source

Abstract

A miniaturized 2.45 GHz microwave ion source (MIS) with plasma chamber of ϕ30 mm × 40 mm that has the ability to produce more than 20 mA CW hydrogen ion beam with 180 W microwave power has been built at Peking University (PKU) 5 years ago1. A hibrid discharge principle has been proposed on this kind of MIS2. Recently, under the structure of this MIS, factors such as input power, pressure, magnetic field configuration and the size of plasma chamber have been investigated. Based on this research, a more compact 2.45 GHz microwave ion source with inner diameter of 24 mm has been developed. A 32.5 mA hydrogen ion beam was obtained with only 100 W microwave power.