CERN Cryomodule Requirements for Crab Cavities O. Capatina (CERN) OC, 2/August/2013 LHC Crab Cryomodule meeting

Functional specification https://espace.cern.ch/HiLumi/WP4/Lists/Team%20Discussion/AllItems.aspx OC, 2/August/2013 LHC Crab Cryomodule meeting

LHC Crab Cryomodule meeting General SPS tests LHC final configuration OC, 2/August/2013 LHC Crab Cryomodule meeting

LHC Crab Cryomodule meeting General LHC environment OC, 2/August/2013 LHC Crab Cryomodule meeting

LHC Crab Cryomodule meeting General LHC environment ~ 10m D2 Q4 IP OC, 2/August/2013 LHC Crab Cryomodule meeting

LHC Crab Cryomodule meeting General LHC environment OC, 2/August/2013 LHC Crab Cryomodule meeting

LHC Crab Cryomodule meeting General SPS environment OC, 2/August/2013 LHC Crab Cryomodule meeting

LHC Crab Cryomodule meeting General SPS environment OC, 2/August/2013 LHC Crab Cryomodule meeting

LHC Crab Cryomodule meeting General SPS : 2 (identical) cavities in a cryomodule 3 different cryomodules OC, 2/August/2013 LHC Crab Cryomodule meeting

LHC Crab Cryomodule meeting General SPS : 2 (identical) cavities in a cryomodule 3 different cryomodules OC, 2/August/2013 LHC Crab Cryomodule meeting

LHC Crab Cryomodule meeting General SPS : 2 (identical) cavities in a cryomodule 3 different cryomodules OC, 2/August/2013 LHC Crab Cryomodule meeting

Geometrical constraints SPS : OC, 2/August/2013 LHC Crab Cryomodule meeting

Geometrical constraints SPS : OC, 2/August/2013 LHC Crab Cryomodule meeting

Geometrical constraints SPS : OC, 2/August/2013 LHC Crab Cryomodule meeting

Geometrical constraints SPS dummy beam pipe : SPS configuration LHC configuration OC, 2/August/2013 LHC Crab Cryomodule meeting

Geometrical constraints SPS - dummy beam pipe : Dummy LHC beam pipe at 194mm horizontally from the SPS beam pipe Dummy beam pipe can be on either side of the cavity but preference opposite to Y chamber OC, 2/August/2013 LHC Crab Cryomodule meeting

Geometrical constraints SPS - dummy beam pipe : Dummy LHC beam pipe at 194mm horizontally from the SPS beam pipe Dummy beam pipe can be on either side of the cavity but preference opposite to Y chamber OC, 2/August/2013 LHC Crab Cryomodule meeting

Geometrical constraints SPS - dummy beam pipe : Dummy LHC beam pipe at 194mm horizontally from the SPS beam pipe Dummy beam pipe can be on either side of the cavity but preference opposite to Y chamber OC, 2/August/2013 LHC Crab Cryomodule meeting

Geometrical constraints SPS – Y chamber apperture: With new Y chamber (510 mm aperture), SPS cryomodule transverse dimensions coherent to LHC => could allow similar SPS/LHC basic solutions for tuner, coupler position SPS cryomodule design should not be over-constrained Baseline: replacing the existing SPS Y chamber OC, 2/August/2013 LHC Crab Cryomodule meeting

Geometrical constraints SPS interfaces: Connexions to main coupler From top, vertically OC, 2/August/2013 LHC Crab Cryomodule meeting

Geometrical constraints SPS interfaces: Connexions to main coupler Limit risk of loads transmitted directly to the cavity from connection to RF module – Double walled tube could be used as part of the supporting system of the cavity OC, 2/August/2013 LHC Crab Cryomodule meeting

Geometrical constraints SPS interfaces: Connection to cryo From top, vertically for main circuits N2 warm return may be sidewise helium tank crab cavity common pumping collector thermal screen at ~80 K cryostat interface CWT Power coupler intercept OC, 2/August/2013 LHC Crab Cryomodule meeting

LHC Crab Cryomodule meeting Alignment LHC - Alignment requirements (position accuracy and position stability) – based on general beam dynamics considerations: Transverse rotation per cavity should be less than 5 mrad Transverse misalignment per cavity (in both planes) should be less than 0.7 mm Cavity tilt with respect to the longitudinal axis should be less than 1 mrad Cavity longitudinal misalignment should be less than 10 mm Active alignment will be studied in a dedicated set-up OC, 2/August/2013 LHC Crab Cryomodule meeting

LHC Crab Cryomodule meeting Alignment SPS Alignment required for operation less than LHC To limit SPS crymodule complexity (win time and limit risk) No active alignment needed for SPS tests Foresee a system for monitoring the cavity positions instead OC, 2/August/2013 LHC Crab Cryomodule meeting

Process & instrumentation Operated at 2 K saturated helium bath -> ~30 mbar Two circuits: 2 K and 80 K Main interface from the top with 4 main lines (LHe IN, GHe pumping, 80 K IN and 80 K OUT): internal pipes welded, external envelope bolted helium tank crab cavity common pumping collector thermal screen at ~80 K cryostat interface CWT Power coupler intercept OC, 2/August/2013 See Krzysztof’s talk LHC Crab Cryomodule meeting

Process & instrumentation 80 K screening will be provided with He or LN2 Power couplers and Cold/Warm Transitions intercepts at 80 K, then outgoing gas directed to recovery line helium tank crab cavity common pumping collector thermal screen at ~80 K cryostat interface CWT Power coupler intercept OC, 2/August/2013 LHC Crab Cryomodule meeting

Process & instrumentation In general: maximize instrumentation for the prototypes Minimum instrumentation requirements: Gauge for helium level measurement from the bottom through the phase separator to be installed for each helium tank (LT x 2) Pressure measurement on the saturated helium bath (PT x 1) Temperature measurement on the bottom each helium tank (suggested CERNOX type transducer, TT x 2) Electrical heaters of 50 W on each helium tank (EH x 2) helium tank crab cavity common pumping collector thermal screen at ~80 K cryostat interface CWT Power coupler intercept SKETCH LT PT EH TT OC, 2/August/2013 LHC Crab Cryomodule meeting

Process & instrumentation Temperature measurement on 80 K screen line (TT x 2 on inlet and outlet) Instrumentation for 80 K intercept circuits – definition underway JT valve and sub-cooling HX are foreseen to be installed out of the cryostat All sub atmospheric instrumentation/safety devices with ambient air interface will have to be equipped with appropriated helium guard. helium tank crab cavity common pumping collector thermal screen at ~80 K cryostat interface CWT Power coupler intercept SKETCH LT PT EH TT OC, 2/August/2013 LHC Crab Cryomodule meeting

LHC Crab Cryomodule meeting Piping sizing Pumping collector sizing (recommended 100mm dia) Gas speed lower than 5 m/s Min 50 mm for level regulation, additional buffer for ~ 20 min of operation Compatibility with safety devices for pressure limit requirements to be confirmed 92 100 mm ~90 mm 0 mm Liquid level ~50 mm Regulation maxi: 5 m/s * Calculation done assuming: collector diameter of 100 mm, He mass flow = 2 g/s, GHe temp = 2 K, GHe press = 20 mbar. OC, 2/August/2013 LHC Crab Cryomodule meeting

LHC Crab Cryomodule meeting Helium tank sizing Helium tank to be dimensioned correctly to extract maximum heat load Heat flux in He II depend on bath temp. and channel dimension OC, 2/August/2013 LHC Crab Cryomodule meeting

LHC Crab Cryomodule meeting Helium tank sizing Helium tank to be dimensioned correctly to extract maximum heat load If helium cross section expected to extract (order of magnitude) 1 W/cm2 => detailed calculations needed Minimize reasonably the liquid helium volume (max. 40 L/cavity if possible) OC, 2/August/2013 LHC Crab Cryomodule meeting

LHC Crab Cryomodule meeting Heat load budget OC, 2/August/2013 LHC Crab Cryomodule meeting

LHC Crab Cryomodule meeting Safety equipment Given its designated function, we are in the presence of ‘high safety relevance’ equipment, i.e., special equipment according to CERN’s SR-M; The HSE Unit Safety Commission shall give clearance from design’s release to commissioning; A Safety File with all relevant technical documentation to be approved by the Safety Commission shall be prepared from day 1 (EDMS); OC, 2/August/2013 See talk of Luis LHC Crab Cryomodule meeting

LHC Crab Cryomodule meeting Safety equipment Two design strategies are possible: to EN Standards or to ASME Section VIII + specific technical requirements; Combined design (EN+ASME) can be accepted if justified; Design shall target the hydrostatic test pressure of 2.6 bar (abs, helium vessel); Equivalent to EN conventional material grades are preferred; ‘Non-conventional’ material properties are to be demonstrated by testing. OC, 2/August/2013 LHC Crab Cryomodule meeting

LHC Crab Cryomodule meeting Materials Helium tank material not imposed; however titanium involves More complex interfaces Not covered by the Harmonised European Standards Stainless steel flanges (1.4429, AISI 316LN) for beam pipe interface Equivalent to EN conventional material grades are preferred OC, 2/August/2013 LHC Crab Cryomodule meeting

LHC Crab Cryomodule meeting Magnetic shielding Static magnetic field shielding required The field to be below 1 µT at the outer surface of the cavity Numerical simulations to determine the material thickness and specification, as well as geometry OC, 2/August/2013 LHC Crab Cryomodule meeting

LHC Crab Cryomodule meeting Cryostating Integration into cryostat at CERN - most likely location SM18 OC, 2/August/2013 LHC Crab Cryomodule meeting

LHC Crab Cryomodule meeting Concluding remark SPS cryomodule: Expected 3 different conceptual designs by the end of the year Collaboration with regular working sessions to merge CERN requirements and LARP/UK effort CERN is ready to help with several competencies OC, 2/August/2013 LHC Crab Cryomodule meeting