Installation of an Instrument on a CERN machine Ray VENESS

Context of the Cockcroft-CERN collaboration Our collaboration includes the design and production of a second gas- jet monitor by Cockcroft/Liverpool for installation in the LHC, with the following milestones: “Design report for a final gas-jet for the LHC” : Report, June 2018 “Full prototype adapted for testing in the LHC” : Hardware, June 2019 This date is consistent with an installation in the next long machine shutdown at CERN (LS2), which will be from early 2019, with LHC access upto summer 2020

Specific issues for integration in the LHC Fully-baked UHV vacuum system Design for (default 250 C) bakeout for all components on the beam vacuum ’Failure tolerant’ gas injection system – don’t vent the LHC with 10 bar N2/Ne! Pumping simulations to estimate the gas load on adjacent (cryogenic and/or RT) systems LHC beam impedance Design to avoid ‘cavity-like’ or ‘antenna-like’ structures that can cause local heating or contribute to beam instabilities Integration Space constraints: longitudinally, transversely, in service tunnels Cabling routes are long and need advance planning Access and environment Access to the tunnel is limited to shutdowns and short technical stops Interventions in the beam vacuum are more difficult and require ~2 weeks for bakeout Radiation damage and single-event failure to be considered for tunnel equipment

Recent example: Beam-Gas Vertex (BGV)

Proposed strategy Start now for any interface issues Integration, cabling, safety and operational scenarios Reserve Space Reservation and Engineering Change Request Start discussions with impedance and vacuum teams Phased approach to installation Phase I : Pull cables, create new vacuum sector (2 valves and associated vacuum instrumentation) Phase II : Install specific BGC beam vacuum chambers, with additional valves where necessary Phase III : Add gas injection and optical systems Phase IV : Commissioning and operations