SPS Upgrade [article]

E Shaposhnikova
An upgrade plan for the whole CERN accelerator complex has been proposed to allow full exploitation of the LHC potential in the future as well as giving increased support to traditional and possible new experiments at lower beam energies. This plan foresees replacing during 2011 -2017 all the accelerators in the LHC injector chain (Linac2, Booster, PS) by new machines (Linac4, SPL and PS2) except for the last -the SPS. In this scenario the SPS should be able to reliably accelerate much higher
more » ... erate much higher beam intensity than achieved so far and therefore significant improvements to the machine performance, in addition to the increased injection energy due to PS2, should be found and implemented on the same time scale. Various LHC upgrade scenarios which are presently under consideration [1] for injectors could be divided into two groups. Most of them are based on the ultimate LHC beam with bunches of 1.7 × 10 11 pp spaced at 25 ns. One scenario, called "LPA" -Large Piwinski Angle, requires bunches spaced by 50 ns with 5 × 10 11 /bunch. All schemes have their own challenges in LHC. The "LPA" scenario requires very high bunch and total beam intensities and is the most challenging for the injectors. At present only the 400 MHz RF system is installed in LHC (the 200 MHz capture RF system is delayed). The LHC beam (4 batches of 72 bunches spaced at 25 ns) with nominal intensity of 1.2 × 10 11 per bunch has been produced at top energy in the SPS [2]. At 450 GeV an average bunch length (4σ Gaussian fit) is 1.6 ± 0.1 ns. The longitudinal bunch displacement at extraction due to the residual effect of beam loading in the 200 MHz RF system (with feedback and feedforward systems in operation) is less than
doi:10.5170/cern-2009-004.43 fatcat:nt3tvt7sc5evvkepp4yrxjp5ui