PPPS-2013: Abstract precise generation of a complex, bipolar, piecewise linear current waveform for a slow kicker magnet

Abstract

The LHC Injector Upgrade (LIU) project aims to prepare the CERN accelerator complex for reliably providing beam with the challenging characteristics required by the high luminosity LHC until at least 2030. Starting at the source a H- beam is accelerated by LINAC4 and then injected into the Proton Synchrotron Booster (PSB). During injection the two electrons of the H- ions are removed with a stripping foil. The protons produced in this way are then accelerated successively by the PSB, the PS and the SPS before being injected into the LHC. When the H-beam is injected into the PSB the machine orbit is shifted across the stripping foil to fill the machine aperture with beam. This shifting of orbit is called `painting' and is accomplished with four slow kicker magnets. The kickers must be well synchronized and with less than 0.5% of deviation from a reference waveform. These kicker magnets will operate with a maximum current of 400A and will have waveforms comprising four different programmable slopes, changeable from pulse to pulse in the range of 10μs to 100μs. Each kicker will be energized by a pulse generator which contains several stages of pre-charged capacitors that one after another are switched to the magnet to generate the current with the required slopes. Additional stages are present to allow fine control of the slope linearity.