ABSTRACT
ECR ion sources have been the subject of active research for many years [1,2]. These ion sources normally operate at lower pressures (10−5-10−8 Torr) and moderate values of microwave power (~1 kW), primarily because of the reduction in the efficiency of ECR action at higher pressures (>10−4 Torr) and stringent cooling requirements. While operation at a lower pressure is favorable for obtaining higher charge states, the beam intensity is considerably limited (approximately electron microamperes) due to a lack of sufficient number density of neutrals. To overcome this problem, several methods such as gas mixing, wall coating, and installation of an electrode into the plasma have been applied [1,2]. However, the maximum increments in beam intensity for a particular charge state are about two to three times larger than what is obtained normally.
