Abstract: A vaporizer system for an ion source includes a radiation source positioned on the vaporizer axis for providing radiation, multiple crucibles radially spaced from the axis and circumferentially spaced from each other and a reflector rotatable about the axis for directing radiation from the source at a selected one of the crucibles. The radiation causes heating of the selected crucible and vaporization of a solid source material contained therein. The radiation source is a visible and/or infrared emitting lamp such as a quartz halogen lamp. The crucibles are thermally isolated from each other by a heat shield so that the selected crucible is heated while the others remain relatively cool.