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

2. 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)

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

4. Pipe specifications (preliminary)

5. 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

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

7. 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

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

9. 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

10. 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

11. 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.

12. Conclusion
Large cold mass and size of the pumping line → a standard 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