Cryostats Some ideas for the new Q1 to Q3 Hi-Lumi WP3 meeting October 22, 2013

Baseline assumptions No jumper on IP-side Return lines inside the magnet’s cryostat (1.9 K pumping, shield, quench/cooldown,…) Cold mass diameter: 630 mm Sliding sleeve with flanges for access to interconnect Cryostat on motorised jacks (must be of new design), no tie- rods, similar alignment stability requirements as now First ideas without busbars routing/interconnection (must be addressed soon)

Current cryostat cross section Heat exchanger Quench line Pumping line OD 1055 Thermal shield cooling “Spider” support Cold mass

Pipe specifications (preliminary)

Standard diameter & centered cold mass He II out (pumping line) Quench return Shield cooling (inlet + outlet) Cold mass Beamscreen inlet (C’) Clearance for orbital welding machines Standard diameter & centered cold mass

Standard diameter & downward offset cold mass Support post not feasible, suspended system not promising Very tight piping integration Standard diameter & downward offset cold mass

Standard diameter & upward offset cold mass Short support post → higher heat load Difficult piping integration (if at all possible), also at the phase separator region Complicated cryostating work No margin from the start!... Standard diameter & upward offset cold mass

Increased diameter & centered cold mass Maximum transport width in the tunnel is 1250 mm, simulation needed (C. Bertone) Simplest cryostat shape Short support post → higher heat load Piping integration ok! Increased diameter & centered cold mass

Incerased diameter & upward offset cold mass Standard support post Piping integration ok Complication of phase separator to pumping line connection (pumping must be above phase separator) Incerased diameter & upward offset cold mass

Elliptical cryostat Simplified piping integration Standard transport width Standard support post Interconnect sleeve is the main challenge (in contact with industry) Cold mass can be centered

Integration in the tunnel: large cylindrical vs elliptical On integration CAD models both cylindrical and elliptical versions seam ok (C. Collazos) . Elliptical has the advantage of easier access for personnel on the sides.

Conclusion Large cold mass and size of the pumping line → a standard 1055 diam. cryostat is most likely not possible Enlarged cylindrical cryostat complicates transport, integration and access in the tunnel: Integration and transport simulation studies required Elliptical cryostat complicates the interconnect sleeve: contacts on-going with industry to address design/fabrication issues Busbar rounting and interconnection study should start as soon as possible Cryogenics P&ID needed to proceed with the conceptual study of the various cryostats