The injection chicane of the National Bureau of Standards-Los Alamos racetrack microtron

A description is given of the method for injection of 5-MeV electrons into the National Bureau of Standards-Los Alamos racetrack microtron, using a dipole magnet on the linear accelerator axis. A three-magnet chicane is used to compensate for the unwanted deflection of the recirculating beam by the injection magnet. In order to minimize emittance growth due to power supply noise, the three chicane magnets are driven by two power supplies, with each supply connected in series to two coils in different magnets. This arrangement, together with the tight space available for the chicane, constrains the choice of conductors and leads to a very precise and compact low-field magnets. Magnetic field measurements that demonstrate that all design goals have been met for the electron injection system are presented