A Fast 650V Chopper Driver

In the framework of Linac4 and the Superconducting Proton Linac (SPL) studies at CERN, the design for a beam chopper has been carried out1. The chopper is basically a kicker that deviates part of the beam towards a dump. It is made of two 50 , slow wave lines facing each other, matching the beam velocity and driven with a minimum of 500 V. Due to the bunch spacing of 2.84 ns, a system rise and fall time (3 %-90 %) below 2.5 ns is required with pulse lengths ranging from 8 ns to hundreds of μs. Although different solutions for the driver amplifier where devised in the past, none of the achievements was entirely satisfactory. This paper describes a new design and prototype that meets all the required specifications.