  A fast-switching, high-repetition-rate magnet and power supply have been
developed for and operated at TRIUMF, to deliver a proton beam to the new
ultracold neutron (UCN) facility. The facility possesses unique operational
requirements: a time-averaged beam current of 40~$\mu$A with the ability to
switch the beam on or off for several minutes. These requirements are in
conflict with the typical operation mode of the TRIUMF cyclotron which delivers
nearly continuous beam to multiple users. To enable the creation of the UCN
facility, a beam-sharing arrangement with another facility was made. The beam
sharing is accomplished by the fast-switching (kicker) magnet which is ramped
in 50~$\mu$s to a current of 193~A, held there for approximately 1~ms, then
ramped down in the same short period of time. This achieves a 12~mrad
deflection which is sufficient to switch the proton beam between the two
facilities. The kicker magnet relies on a high-current, low-inductance coil
connected to a fast-switching power supply that is based on insulated-gate
bipolar transistors (IGBTs). The design and performance of the kicker magnet
system and initial beam delivery results are reported.
