A system for improving ion beam quality is disclosed. According to one embodiment, the system comprises an ion source, having a chamber defined by a plurality of chamber walls; an RF antenna disposed on a first wall of the plurality of chamber walls; a second wall, opposite the first wall, the distance between the first wall and the second wall defining the height of the chamber; an aperture disposed on one of the plurality of chamber walls; a first gas inlet for introducing a first source gas to the chamber; and a second gas inlet for introducing a second source gas, different from the first source gas, to the chamber; wherein a first distance from the first gas inlet to the second wall is less than 35% of the height; and a second distance from the second gas inlet to the first wall is less than 35% of the height.