Crab Cavities SPS cryogenics progress and requirements Fermilab - PowerPoint PPT Presentation

Crab Cavities SPS cryogenics – progress and requirements Fermilab visit at CERN 02 August 2013 Krzysztof Brodzinski (on behalf of CERN cryogenic team) 1

Contents • Cryogenics for Crab Cavities project – technical aspects and status • Circuits • Heat load • Capacity limitations with existing infrastructure + possible solutions • BA4 work progress • 2 K pumping units test • Available space – integration brief • Cryogenics for SPS cryostat design • Process and instrumentation • Safety devices • Pumping collector sizing • Superfluid helium layer • Conclusions 2 K. Brodzinski - Fermilab visit_2013.08.02

Cryogenic circuits Regarding 2 K refrigeration Additional He source Buffer tank R EH Service module TT LN2 JT CC cryostat Screen PT LT Coupler intercept CTW CC x 2 CTW black – > existing 4.5 K Screen red – > to be constructed 2 K EH TT 3 K. Brodzinski - Fermilab visit_2013.08.02

Heat loads and TCF20 capacity The below values are calculated/estimated – no exact calculation is available yet depending on design Equipment Heat load Source of capacity cryostat Static HL @ 2K ~ 8-10W TCF20 -> 0.4-0.5 g/s Dynamic @ 2 K ~ 5-10 W TCF20/Buffer tank HL @80 K ~40-60 W LN2 Service module ~2.5 W @ 2K TCF20 -> 0.13 g/s ~30 W @ 80 K LN2 Buffer tank* ~1.5 W @ 4.5 K TCF20 -> 0.08 g/s ~ 19 W@ 80 K LN2 V. Parma and colleagues Transfer lines ~3.4 W @ 4.5 K TCF20 -> 0.17 g/s ~26 W @ 80 K LN2 Flash at 2 K ~20% of liquefaction flow TCF20 -> 0.2 g/s Total net value: 0.98-1.08 g/s Total with 1.5 safety factor: ~ 1.5 g/s 4 K. Brodzinski - Fermilab visit_2013.08.02

TCF20 cold box capacity discussion Static heat load -> 0.98-1.08 *1.5 =~1.5 g/s CERN isentropic equiv. recalculated with measured refrigeration capacity (120 W) CERN isentropic equiv. recalculated with guaranteed refrigeration capacity (85 W) CERN isentropic equiv. recalculated (20 l/h) Liquefaction capacity line [g/s] 0.7 0.85 1.2 0.76 1.56 LEGNARO guaranteed liquefaction capacity (22 l/h) LEGNARO guaranteed liquefaction capacity with LN2 (45 l/h) Conclusions: • Existing TCF20 without LN2 boost is not sufficient to cover requirements (even upgraded as liquefier) • Plan B: LN2 boost to be installed and liquefaction capacity tested • Plan C: install new TCF20 liquefier + install LN2 boost (difficult because of safety and a lot of work – transfer lines to be installed, possible problems with instabilities of LN2 flow – info from G. Passardi) • Plan D: on the surface: Install a 10000 L dewar with link to 200 L buffer as an “emergency boost” Target: The cold box should cover at least the static heat load, the buffer tank dynamic operation of the cavity. 5 K. Brodzinski - Fermilab visit_2013.08.02

Work done in BA4 • Inventory list, GMAO new naming definition list and PID update done by ~15.09.2012 • All SVs re-qualified and installed – done by ~15.09.2012 • Electrical motor and compressor maintenance – done by ~30.09.2012 • Oil separation refurbished (coalescers cartridge replaced, ADS charcoal replaced) – done by ~30.09.2012 • Storage – He tank re-qualified as pressure recipient – done on 12.09.2012 • All other pressure recipients re-qualified – done by ~15.10.2012 • Purging system on compressor station refurbished • Cooling water and air ventilation installations for compressor station – refurbished • Cold box vacuum system revised and partially refurbished • Compressor station and cold box (partially) instrumentation revised • Compressor station new electrical supply system with documentation done and tested by ~15.11.2012 • Control system well advanced (partially ready) • He tightness test done on compressor station • First run of compressor station done by 30.11.2012 – milestone (OK operational, HP@6 bara) • First helium flow through the cold box done on 18.12.2012 – milestone (OK, no leak into the vac) 6 K. Brodzinski - Fermilab visit_2013.08.02

Work done in BA4 At SPS BA4 there is a 4.5 K cryogenic infrastructure used last time about 8 years ago for COLDEX experiment. It is foreseen to test its capacity and upgrade it for 2 K refrigeration – refurbishment is underway Renovated compressor + elec. motor – run test done Revised, labeled and qualified pressure control system / oil removal system Cold box TCF20 New power supply panel for compressor station 2 K pumping groups recovered from AMS SPS LS1 time frames: Open Access : 25/03/13 TCF20 Cold box 7 K. Brodzinski - Fermilab visit_2013.08.02 Close Access : 27/06/14

2 K pumping units performance test PT TT PSV PT PI HV HV 01 01 01 02 03 02 03 PI 02 FT PI Recuperation line 01 HV 2 stage pumping towards liquifier 04 HV 01 group 2 stage pumping group (Leybold: RUVAG WS2001 and SV630) 2 batteries of He gas bottles PT01: pressure transmitter, Rosemount, 0 … 2000 mbara <200 bar TT01: Pt100 FT: flow transmitter, Brooks, 0 … 1.5 g/s PT02: pressure transmitter, GE, 0 … 100 mbara Both pumps were run to check their capacity – probably 2 pumps will have to be integrated in the tunnel – analysis underway. 8 K. Brodzinski - Fermilab visit_2013.08.02

Cryo integration in SPS Pump heater SM Buffer TCF20 Very tight integration if going behind the beam line (more details in Th. Renaglia presentation). 9 K. Brodzinski - Fermilab visit_2013.08.02

Tentative SPS CC cryogenic schedule Work planned for 2013: - 2 K pumping group to be transported and integrated in the SPS tunnel in Autumn 2013 – AMS groups will be used - Low pressure He recovery heating system to be transported and integrated in the SPS tunnel in Autumn 2013 – probably AMS elements could be adapted - Electrical and control systems for 2 K cryogenics to be done (cables pulling included) – underway - Refurbishment of the cold box 4.5 K – vacuum system and turbine circuits – done - Cold box control system to be completed – done - Cold box instrumentation revision/update to be completed – underway - Cold run of the cold box – in September May 2013 – milestone – almost ready, conditioning done, waiting for cooling water circuit ON - Liquefaction test of 4.5 K cold box (potentially with boost at 80 K stage, if yes, this boosting system is to be developed and bought/constructed), some hardware modifications are required as preparation for this test – to be done by 15.10.2013 – milestone - Refurbishment of the supply/recovery system between BA4 and North Area is to be done or procurement of additional buffer tank to fulfil requirements of helium availability for CC testing – to be analysed and confirmed – spring/autumn 2013 – milestone - LN2 system for cooling of screen circuits to be developed and bought – to be defined - Buffer tank to be designed and bought - 2 K cryogenics: transfer line system to be designed and ordered (installation in 2014) - 2 K cryogenics: Service module to be to be designed and ordered (installation in 2014) Main task for 2013/2014 is the distribution system development and installation 10 K. Brodzinski - Fermilab visit_2013.08.02

Process & instrumentation 1/2 The cryostat will house 2 crab cavities and will be operated at 2 K (saturated helium bath  ~30 mbar). The design should be done in the way to minimize the static heat load at 2 K (important!) It will be equipped with two circuits 2 K and 80 K. The main interface should be provided from the top with 4 main lines (LHe IN, GHe pumping, LN2 80 K IN and 80 K OUT). - Proposed piping should cover nominal operation and transients (cool down and warm up), - Interface to the cryostat: internal pipes welded, external envelope bolted (allowing opening of the jacket by means of sliding it up or down). Power couplers and Cold/Warm Transitions will be intercepted with LN2 at 80 K. cryostat interface thermal screen at ~80 K common pumping collector helium tank CWT crab cavity CWT Power coupler intercept 11 K. Brodzinski - Fermilab visit_2013.08.02

Process & instrumentation 2/2 The cryostat should be equipped with the following instrumentation: • Helium level measurement – each helium tank should be equipped with a level gauge allowing for helium level measurement from the bottom through the phase separator (LT x 2, each gauge should allow for helium level regulation in the phase separator collector), • Pressure measurement on the saturated helium bath is to be provided (PT x 1), • Temperature measurement on each cavity helium tank is to be provided, installed on the bottom of each helium tank (suggested CERNOX type transducer, TT x 2), • Electrical heaters of 50 W are to be installed on each helium tank (EH x 2) • Temperature measurement on 80 K screen line is to be provided (TT x 2 on inlet and outlet) • JT valve and sub-cooling HX are foreseen to be installed out of the cryostat • (instrumentation for 80 K intercept circuits – definition underway) All sub atmospheric instrumentation/safety devices with ambient air interface will have to be equipped with appropriated helium guard. cryostat interface thermal screen at ~80 K common pumping collector TT TT LT LT PT helium tank CWT crab cavity TT TT EH EH CWT Power coupler intercept 12 K. Brodzinski - Fermilab visit_2013.08.02