Status of QQXF cryostat D. Ramos, C. Eymin, M. Moretti, 3.12.2015

First things first: Present cryo layout (R. Van Weelderen and D. Berkowitz, 19-11-2015) Note: We are free to choose the HX position but both must be at the same height

Some key spec’s and constraints Alignment of the magnets by adjustment of the position of the complete cryoassembly through fiducials outiside the vacuum vessel (no adjustment of cold mass wrt to vacuum vessel after assembly) Deviation in time of relative position between cold mass and vacuum vessel will be monitored Motorised jacks with remote control to correct alignment of the cryoassembly (ZX plane only) Transport constraints in the tunnel impose maximum width equal to present LHC cryostats: overal maximum 1072 mm / flange OD 1055 mm [C. Bertone, 14-11-2014] Static heat loads comparable to the LHC arcs and MS Columns under compression as cold mass support principle Cold mass stands on at least three points at all times Isostatic anchoring of vacuum vessel is an advantage

The QQXF as it looks today

Cryo piping diameters are first estimations, all to be confirmed by TE/CRG Ø 1055 (upper limit for transport in the tunnel) Ø 914x12 Maximised offset to open space for piping integration GFRE support column w/ maximum diameter for dynamic stability Two-piece column for acessiblity during assembly Cold mass support assembly after cryostating

Reinforcing rings to prevent ovalisation Fixed support post in the middle for better cold mass stability when handling Longitudinal ribs for increased bending stiffness Isostatic vacuum vessel supports (3 points) postioned for minimum cold mass bending

Tie rod for longitudinal loads Isostatic anchoring Y X Z “Vacuum force” (~80 kN, Q1 only) (free,free,0) (0,free,0) (0,free,0) Tie rod for longitudinal loads (free,0,free) Pressure end effect from cold mass interconnect (depends on interconnect design)

Cryostating tooling: sledge on rails The principle currently used in dipoles and long SSS Cold mass supported on at least 3 points at all times Minimum gaps for cold mass insertion and removal of sledges must be accounted for

Cold mass+shield lifted wrt nominal Cryostating tooling Cold mass+shield lifted wrt nominal Sledge on rails Lifting jack Lifting jack Support assembly Tooling removal

Cold supports The 60 K heat intercept position along the support post length optimized for minimum exergetic cost. For cooling at 60 K (Cs = 15) and at 1.9 K (Cc = 1000) CENTRAL FIXED SUPPORT SLIDING SUPPORT Optimum at 37 mm for heat intercept at 60 K: 8.1 W at 60 K and 0.3 W at 1.9 K

Thermal Shield Thermal model FIXED SUPPORT SLIDING SUPPORT 5 mm thickness, supported at the heat intercepts: No additional heat loads to 1.9K Deformation under self weight ~2 mm FIXED SUPPORT SLIDING SUPPORT 0.28 W to 1.9 K 0.46 W to 1.9 K Thermal model

Distance between cold mass supports a = 3500 mm length 9.785 m weight 22.5 ton Minimum deflection at a = 0.715xL/2 ≈ 3500 mm

Vacuum vessel No axial load “Vacuum force” (~80 kN, Q1 only) Placement of jacks as optimised for minimum cold mass bending in layout version LHCLSXH_0010 AB: - 0.25 mm - 0.23 mm - 0.24 mm 2560 2560 No axial load Cold mass weight: 22.5 ton - 0.26 mm - 0.16 mm - 0.39 mm “Vacuum force” (~80 kN, Q1 only)

On-going work Full integration 3D model: without it’s impossible to know where each pipe should be and how can they be connected (extremely compact integration)

On-going work Overal schematics including cryogenic piping and busbars Development of management process for parts, configurations, assembly and logistics Modelling of dynamic response to ground vibrations Iterations as more data from cryo and powering becomes available

LHC triplet and dipole cross sections Preference for column support posts but LHC layout cannot fit a larger cold mass plus pumping lines