The H- High Intensity Beam Extraction System for TRIUMF

The TRIUMF cyclotron is being upgraded for extraction of a 100 ¿A H- beam at an energy of 450 MeV for injection into a post-accelerator. The system includes RF cavities operating at the 20th harmonic of the ion orbit frequency to boost the energy gain per turn to 1 MeV, an RF radial deflector at one-half of the RF fundamental frequency for turn dilution, electrostatic deflectors with a prestripper, and iron-free magnetic channels. The principal requirements for these additional devices are outlined, as well as the space and radiation constraints they must satisfy. The layout of the extraction system with respect to the beam trajectories and the mechanical and electrical design concepts of the devices are presented and discussed.