1. Installation of an Instrument on a CERN machine
Ray VENESS

2. 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

3. 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

4. Recent example: Beam-Gas Vertex (BGV)

5. 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