CERN Accelerating science

  Upgrading together, HL-LHC and LIU
  by Kate Kahle (CERN)


The Linac4 accelerator tunnel. Linac4 is the first step of the LHC Injector Upgrade (LIU) project.
Image credit: CERN

On 30 March, participants from the High Luminosity LHC upgrade project (HL-LHC) and the LHC Injector Upgrade project (LIU) held a joint meeting aimed at converging on a set of achievable beam characteristics. After a welcome from Steve Myers, CERN Director of Accelerators and Technology, Mike Lamont gave a summary of the 1st combined meeting held in June 2011.

A talk by Verena Kain describing the transverse emittance blow-up and beam loss presently measured between injection and collision in the LHC itself. Oliver Bruning, deputy project coordinator of HL-LHC, then gave an update of the required beam characteristics at injection energy and Stephane Fartoukh spoke of a micro-batch filling scheme for pacman cancellations. HL-LHC talks concluded with new ideas from Frank Zimmermann including pile-up levelling versus luminosity levelling schemes and the potential gains and losses in performance.

LHC Injector Upgrade talks began with an analysis of the 2011 injector performance by Giovanni Rumolo, after which Brennan Goddard provided an update of achievable beam characteristics at injection. Roland Garoby, head of the LIU upgrade, commented on the means to bridge the gap between the HL-LHC requirements and the potential of the injectors.

In a question and answer session in the afternoon, discussions included the pros and cons of 25 and 50 nanosecond bunch spacing, and of overlapping LIU and LHC beam parameters. A summary will soon be linked to the agenda but for now all presentations are available online.

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