1200A High Speed Injection and Extraction Kicker Magnet Drivers for EMMA

EMMA (Electron Machine for Many Applications) is a proof-of-principle non-scaling fixed field alternating gradient accelerator designed to accelerate electrons from the Energy Recovery Linac Prototype (ERLP) under construction at STFC Daresbury Laboratory. The electrons are extracted from ERLP after the first pass through the main linac and injected into EMMA at energies of 10 MeV. Each bunch will make 10 turns of the ring during which time the energy is raised from 10 MeV to 20 MeV. The time for the bunch to make one revolution is 53 ns which imposes the requirement that the falltime for the injection driver must be<50 ns with a postpulse current of <1%. Similar considerations dictate that the risetime of the extraction driver must be ,<50 ns with a prepulse current of <1%. The low inductance kicker magnets require 1200 A current pulses. APP has developed solid state drivers that with minor modifications can be used to meet either application. The driver has 2 PFN´s with each end of the kicker magnet connected to one PFN. The PFN´s are charged to 20 kV in approximately 200 ns. A magnetic switch across one pulse PFN inverts the voltage on that PFN, resulting in a fast rising and falling current through the kicker magnet. Ferrite loaded lines and shunt resistors are used to eliminate pre and post-pulse current. This paper will describe the performance of this system.