Achievement and control of the 100 μA beam at triumf

TRIUMF has recently achieved its design goal of a 100 μA, 500 MeV proton beam to the meson production target. Beam losses are particularly critical along the 40 m long 300 keV electrostatic injection line where beam heating can cause metallization of the insulators. Activation criteria limit the spills at higher energies although the possibility of thermal damage cannot be excluded. A number of special devices have been built to control beam losses and simplify high current operation. These include a variable duty-cycle electronic pulser in the ion source terminal, halo monitors and nonintercepting beam transformers in the injection line, secondary emission spill monitors in the cyclotron and target protect monitors, capacitive and radiation monitors along the external beam line. The procedure followed in setting up high current beams and the special systems designed to maintain acceptable losses will be described.