Deliverable 2.7: Analysis of the existing sources of blow-up in the SPS by experiments and estimation/measurement of the effect of the crab cavities in the SPS

Abstract

The Crab Cavities (CCs) may induce emittance growth, driven by phase and amplitude jitter, and lead to a degradation of the High Luminosity LHC (HL-LHC) beam. Furthermore, the tight HL-LHC space constraints call for non-axially symmetric cavity designs that come with higher order non-linearities which can affect the long-term dynamic aperture (DA). In order to study the effect the CCs have on the beam and the engineering challenges to validate the pre-series design, a prototype HL-LHC CC set was installed in the SPS machine in the year-end technical stop (YETS) of 2017-2018, and the first ever CC tests with protons were performed in 2018. This note is a collection of the reports and work done on the emittance growth measurements prior and after the CC installation, as well as simulations and measurements performed to study the CC and SPS non linearities effect. Finally, a summary of the instrumentation observations of the SPS CC experimental measurements is presented