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ColUSM #51 30 th January, 2015 D. Duarte Ramos, C. Mucher, L. Gentini, T. Sahner, H. Prin, R. Wawrowski, Q. Deliege, V. Baglin, F. Savary

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Click here to add footer 2 Outline Specifications, constraints and goals As-installed magnet length Continuity of cryogenics and powering (how did we got to the current layout) Beam vacuum components and achievable collimator length Conclusion and comments on eventual specification changes

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Click here to add footer 3 Specifications, constraints and goals Compatibility with installation and transport constraints: not larger than existing cryostat (1055 mm) Create a room temperature vacuum sector in the LHC continuous cryostat Cold to warm transitions (CWT) Sector valve after each CWT for vacuum separation during magnet cooldown or collimator bakeout. RF- shielded gate valves and bellows for impedance reasons DN35 ports on the cold sectors to send an RF emitter ball through the full arc after warm up and before cooldown Compatibility with existing cryogenic and electrical systems, ensuring their continuity Prevent loss of alignment during evacuation with independent supports for collimator and cryostat Minimise changes to other magnets: keep interconnects standard if possible Collimator Vacuum enclosure Magnet 1.8K Heat exchanger Beam vacuum Lines E, C, K RF emitter Bus bars

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Click here to add footer 4 Layout options (January 2013) New end covers may be made to route the bus bars in a way to provide enough space for the collimator. The price is loss of interchangeability betwen cold masses Retained Additional module needed to create a standard interconnect interface and thermal compensation. Interference with W sleeve. Not possible to fit the collimator nor sector valves between standard bus bar lines. New routing needed to make vertical space for the collimator

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Click here to add footer 5 As installed magnet length i.e. ~3.1 m availabe for collimator, interconnects and remainder equipment

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Click here to add footer 6 1 st Concept (Dec 2013) Independently cryostated and handled cold masses, linked through two short transfer lines Transfer lines with expansion joints mechanically decouple cryostats A and B Splice and piping interfonnect in the tunnel, all other work prior to installation Can use the existing TCLD collimator design with modified the supports Collimator Lines M, E, N, K, C Reinforced jacks to widstand vacuum forces Cold mass ACold mass B Line X Independently supported collimator Busbar splice and interconnect done in the tunnel Flexible S-shaped busbar stabiliser Busbar lyra

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Click here to add footer 7 1 st Concept (Dec 2013) 800 mm Collimator Compatible with the collimator design developed in 2010 (TCLD) Starting assumption: busbar bypass can be made in the shadow of the beam screens and CWT

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Click here to add footer 8 After long months of idea generation and testing The busbar routing proved to be a major challenge! Six busbars in one duct: how to route lyras, large bellows, space for an extra interconnect at the exit of the CM External MQ busbars: How to connect to the existing magnets, space for the interconnect at the exit of the CM for line M3 Three separate ducts for each pair of bus bars: better but length to accomodate the pipe bends and interconnect length still an issue Busbar bypass can be made in the shadow of the beam screens and CWT Can Not

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Technology Department Present layout Current working design Design proposal 2 nd Concept: 2 magnets in one cold mass QTC-like short bypass module upstream of 11T Two-in-one cold masses imply moving several magnets radially or using orbit correctors to compensate for the fact that the cold mass is straight Still not possible to route the busbars without taking more length than required by the beam vacuum components Herv Prin, April 2014

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Click here to add footer 10 May 2014: A new approach QRL side K2 M2 V2 W Y M1 M3 E C V1 K1 X N

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Click here to add footer 11 3 rd Concept (current baseline) Same 15660 mm length between interconnect planes as an LHC MB Connection cryostat between two 11 T magnets to integrate the collimator LHC MB replaced by 3 cryostats + collimator, all independently supported and aligned: Same interfaces at the extremities: no changes to nearby magnets, standard interconnection procedures & tooling

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Click here to add footer 12 Connection cryostat for collimator integration Collimator support jacks Cryostat support jacks Cold mass enlarged to 750 on the collimator side Constant LHC arc outer flange diameter: 1055 Flexible interconnects for alignment independency and thermal contraction Interconnects usestandard componentsand tooling despite thenew compact layout Busbar routing is now in the shadow of the beam screens and CWT!

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Click here to add footer 13 Cross section of the connection cryostat and collimator Dedicated collimator design. One collimator design fits both beam lines M2 W Y M1 M3 E C X N Collimator supported directly on the concrete slab Larger cold mass extremity to open up space for the collimator

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Click here to add footer 14 Beam vacuum & Collimator length (1) 600 mm Collimator Warm drift vacuum chamber Possibility of getting extra 50 mm but the interconnects will not have the same length: 2 vacuum vessel variants or 2 interc. sleeve variants Transitions needed to allow installation of sector valves Very tight integration

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Click here to add footer 15 Beam vacuum & Collimator length (2) Interconnects become longer because of the beamscreens Very compact cold line because of the sector valve RF shielding Transitions avoided because there are no sector valves on the other beam lines Cold drift vacuum chamber 650 mm Collimator

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Click here to add footer 16 Conclusion The present baseline layout allows to connect busbars and cryogenic lines without impact on the length of the collimator Beam vacuum, design for RF impedance, minimised radiation to personnel and beam line inspection with emitter ball impose a minimum length of beam line components, thus defining the collimator length Detailed design studies revealed the constraints imposed by the beam line without collimator Both warm and cold versions of that line require validate with physical mockups/prototypes (preparation starting the coming weeks) Should the outcome be positive, the collimator active length can be 650 mm.

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Click here to add footer 17 More space for the collimator implies compromising No ports for RF ball test: +130 mm (applies to both versions) No beamscreen on line without collimator: +120 mm (applies to cold version only) Ex. no RF ball ports + no beamscreen + no quick flange: +310 mm (applies to cold version only) No quick flange on collimator: +60 mm (applies to both versions)

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Click here to add footer 19 Current leads for the trim circuit 2x 300 A conduction cooled leads Only one location is possible Integration and design to be started Gas cooled leads not possible both for lack of space and cryogenics Conduction cooled leads: about 3.6 W/kA to 1.9 K (c.f. A. Ballarino) Local solution: applicable everywhere in the LHC RT copper cables towards power converter Similar to a Dipole Corrector Feedthrough in the SSS (EDMS 328999)

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Click here to add footer 20 Delio.Ramos@cern.ch Before the 11 T magnet development: QTC (2010) Main drawback: extensive machine layout changes to create space 4.0 m + 0.5 m interc. = 4.5 m installation length

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Click here to add footer 21 Delio.Ramos@cern.ch Could the QTC cryostat concept be extended? Can only be finished after cryostating Dealing with welding distortions is a major issue Distortions amplified with length Adjustment of cold supports posts is required Complicated assembly procedure Longitudinal butt-welds Cover closure w/ fillet welds New approach needed