Magnet & services projects P. Tropea 9 Nov 2011 – CMS upgrade workshop

CMS Upgrade Workshop 9 November 2011 P. Tropea Contents CONSOLIDATION Magnet infrastructure Water & Fluorocarbon cooling General services UPGRADE Pixel phase I CO 2 cooling RE4 cooling 2

CMS Upgrade Workshop 9 November 2011 P. Tropea Magnet (courtesy B. Cure) Magnet operation in 2011 (since Feb restart till Oct 2011): 84.8% of total time at 3.8T 11.6% of total time with planned magnet stops 3.6% of total time with unexpected magnet stops 100% available for physics at LHC. Three faults, both recovered in 4 days: faulty valve position controller mismatch of cryo parameters (operator mistake), following intervention on cryoplant during the July TS and the following power cut Switch off of all magnet power converters (procedural problem) Increase reliability & redundancy of services to reduce failure impact & limit the magnet cycling, in order to maintain expected magnet availability and lifetime! 3

CMS Upgrade Workshop 9 November 2011 P. Tropea Magnet cryo & cooling (courtesy B. Cure) Cryo compressors: standard revision demands several months with magnet off. Any failure would imply long waiting time, since compressors are not off-the- shelf components. Low efficiency (still within specs) due to the non optimal lubricant separation system  2 new compressors to be installed in order to guarantee full redundancy: scheduled for LS1, critical parts already ordered (rotor, casing, bearings, motors)  Issue with lubrication separation system addressed (common issue with LHC machine cryoplants) : helium dryer (+ purifier, to be confirmed) to be installed during LS1 Busbar cooling: coupled through buffer tank to Yoke and Endcap cooling (possible stoppage during maintenance operation on the latters). Requirements on EDMS , project launched with EN/CV for LS1 4

CMS Upgrade Workshop 9 November 2011 P. Tropea Magnet safety & control system, power (courtesy B. Cure) 1.MSS chassis: new spare units shall be built with up-to-date electronics 2.MSS powering: modification of the 55V batteries, to replace the chargers and their supervision: increase the charger reliability and improve the supervision and alarm to the ANS 3.Transformer 18kV / 400V: no spare transformer reserved for CMS on the magnet power line, backup plan is to temporarily connect on adjacent transformer in USC55 before a new transformer is delivered. 5

CMS Upgrade Workshop 9 November 2011 P. Tropea Water cooling: consolidation Consultation with EN/CV in October, agreement to plan all activities and finalize studies by beginning of Operation improvements Additional monitoring & verification of DSS cabled alarms Action matrix on humidity level alarms to be updated (stop of rack circuit incident on August 3 rd ) Backup chiller during maintenance/major incidents? Ecal cooling system Slow response of T regulation to changes of load or primary cooling T Too high sensitivity to small flow/temperature changes on CMS side Review with CMS and CV people to be organized asap 6

CMS Upgrade Workshop 9 November 2011 P. Tropea Water cooling: leak risk mitigation Since Jan 2010: 24 leaks (all detected by inspections, except one spotted by leak detection cable). Rack circuit is the most critical (19 leaks), followed by the Muon circuit. 1.Modify critical racks (Tracker) to make connections accessible: on- going study 2.Improve leak detection system: calibration of leak sensors to retrieve leak position graphic interface to have a faster feedback (DSS team, cooling team, Sensors 4CMS team) 7

CMS Upgrade Workshop 9 November 2011 P. Tropea Fluorocarbon circuits: “go cold” & reliability Tracker cooling working group (Chair: A. Onnela, members: Tracker, EN/CV/DC, PH/DT) is in charge for evaluation of main interventions towards long term improvements on cooling system and implications of running at much lower temperatures after LS1 -Performance test: to assess the capacity of the system to cope with low T and demanded power, including Pix CO 2 plant (ETS 2011/2012) -Dryness of cooling cabinets & environment for Tk maintenance -Pneumatic cabinet revamp to increase reliability -Backup chiller full commissioning for Thermal Screen and Preshower plants -Additional monitoring instrumentation (vibration, fast pressure transducers, etc.) 8

CMS Upgrade Workshop 9 November 2011 P. Tropea General services Gas nitrogen for detector dryness Additional N 2 gas flow needed. Full picture on EDMS To be completed with updated Tracker needs once humidity issues assessed SHL5 Pixels lab Climatic chamber: T and RH regulation ranges defined, structure being prepared and HVAC works to be done in 2012 UXC55 Temperature/Humidity control Cavern temperature above 20°C all year long Huge sensitivity of RPC to ambient temperature Additional load to the cavern from ECAL cables Need for understanding present system limits and possible cures, project launched with EN/CV Rack cooling turbines -Mandatory to replace all turbine motors in magnetic field in LS1 -Considering replacement of turbine motors in USC as well 9

CMS Upgrade Workshop 9 November 2011 P. Tropea Pixels phase I CO 2 (see talk by H. Postema for further details) On-detector cooling design ongoing -Definition of cooling loops length (PSI, FNAL) -Thermal performance tests and simulations (PSI, FNAL, CERN) Conceptual design mostly ready for cooling plant -Components being selected (CERN/Lyon) -3D modeling started (Lyon) -Control system studies started (CERN) Qualification of copper pipes -Resistance to high pressure approved by CERN safety 240 bar) -Full scale mock-up for flow regime investigation ready, tests to start in few weeks (CERN) Installation studies -Two possible locations: USC or UXC -Radiation protection studies ongoing 10

CMS Upgrade Workshop 9 November 2011 P. Tropea RE4 cooling manifold (courtesy D. Loveless) RE Proposal –Design Xmas towers in accessible location –Run laterals from the towers to the chambers Use hoses, not copper pipe RE chambers have pigtails, connect via O-rings –Design should take 3-4 weeks –Production of stainless piping can be done by local firm CSC Connections exist –Purchase fittings 11 Main issues to be addressed: integration, coordination of installation works and commissioning Same design to be considered for YE1 possible consolidation…

CMS Upgrade Workshop 9 November 2011 P. Tropea Summary Infrastructure consolidation, even if not so fancy, is mandatory to guarantee a good data taking reliability A number of projects are well defined and already in the pipeline for LS1 Some other projects need time and resources to advance: N 2 plant… Consolidation projects strongly influence also upgrade (see primary circuit for Pix CO 2 plant) Cooling for upgrade is in good shape: projects are progressing and resources are well allocated 12