HL-LHC-UK Thermal Shield Update Niklas Templeton 07/03/2016

Design Overview 2 Concepts being developed in parallel for comparison… 4 Flexure support Optimised Global cooling circuit Sheet metal design with reinforcement for modal stability and minimal sagging Top plate geometry optimised for integration, ease of manufacture and assembly, MLI dressing Accurate Penetrations for tuner, FPC, FSI, HOM Lines, Beam Lines, BCAM Additional penetrations for cable routing required 5 Thermal probes at: Inlet, Outlet, HOM2 (top), HOM6 (btm), FPC2 HOM & FPC Heat Loads applied directly to pipe

Shield Concepts Aluminium Concept 3mm thick panels + single U rib Clamped cooling pipe connection Steel cooling pipe for ease of Cryo-line integration HOM & FPC heat loads applied directly to pipes Copper Concept 2mm thick panels + sheet metal stiffeners Fully brazed Copper cooling circuit with 4 Cu-SS pipe transitions Heat loads can be applied to pipes or panels 179 kg 91 kg

Quick Comparison Aluminium Concept Cheaper, Lighter, Stiffer Greater manufacturing precision of top plate Ease of cryoline integration (SS-SS) and welded pipe intercepts Copper Concept Greater thermal performance Pipe or panel intercept options Qualified pipe connections Single material (thermal expansion) AlOFHC Heat Load K (J/kg) Mass (Kg) Load (kJ)15,94314,037

Modal Behaviour Aluminium Concept 3mm thick panels 1 x U rib stiffener Copper Concept 2mm thick panels 3 x sheet metal stiffener ModeFreq. (Hz)Location Windows Bottom ModeFreq. (Hz)Location Windows Front 619.8Back Fundamental Mode

Structural – Self Weight Aluminium Concept 0.56mm sag on top plate Copper Concept 0.8 mm sag on top plate Top plate reinforcement difficult due to spatial constraints

Thermal Performance Aluminium Concept K Pipe Temperature Al-Al TCC: 250 W/m 2.K Al-SS TCC: 150 W/m 2.K HOM & FPC loads applied to pipe Results Panel T: 64-81K Pipe T: K * *Optimisation of intercepts required Copper Concept K Pipe Temperature Panel TCC: 500 W/m 2.K Pipe-Panel: Bonded All heat loads applied to panel Results Panel T: 53-75K Pipe T: 50-70K

Convection Coefficient Calculation Calculations U (m/s):3.72 Re:26677 Pr:0.78 h (W/m 2.K): Flow Properties P (Bar)4 m (kg/s)2.20E-03 T (K):50-70 Fluid Properties μ (Pa.s)7.50E-06 k (W/m.K)0.05 c p (J/kg.K):5200 ρ (kg/m 3 ):3.84 Pipe Properties D (m):0.014 Heat Transfer Coefficient Dittus - Boelter Correlation for turbulent pipe flow (Accuracy ±15%) Pipe Thermal Gradient ElbowPipe Length (mm)Heat Load (W)T(K)h (W/m 2.K) Pipe Temperature replaced with Convection – Film Coefficient: 250 W/m 2.K & Ambient Temperature gradient

Thermal Performance with Helium Convection Aluminium Concept K Pipe Convection Al-Al TCC: 250 W/m 2.K Al-SS TCC: 150 W/m 2.K HOM & FPC loads applied to pipe Results Panel T: 70-87K Pipe T: K * *Optimisation of intercepts required Copper Concept K Pipe Convection Panel TCC: 500 W/m 2.K Pipe-Panel: Bonded All heat loads applied to panel Results Panel T: 55-84K Pipe T: 50-75K

Thermal Performance Summary Result Summary Pipe TemperaturePipe Convection T min (K)T max (K)T min (K)T max (K) Al/SS Panels Pipe Cu Panels Pipe Al Cooling Temp. Al Cooling Convection SS Cooling Convection Cu Cooling Temp. Cu Cooling Convection

Initial Cool Down Boundary Conditions: Pipe Temperature: 50 K Panel Temperature: 295 K Fixed at Flexure interface To be repeated for initial conditions. Stress (Mpa) Al PanelSS PipeCu PipeCu Panel Initial Condition 1xxxx 2xxxx 3xxxx 4xxxx 5xxxx Panel stress results Al (left) & Cu (right) - Worst Case Initial Conditions *Preliminary Results - simulation not yet refined Pre-cooling of shield

Concept Variant Analysis Criteria Evaluation 1Poor 2OK 3Good 4Great Draft calculation Shield Concept Design CriteriaWeightingCopperAl / SS Thermal performance (Radiation, Cool Down, etc.) 4043 Qualification (testing of joints/connections etc.) 2042 Manufacture precision (top plate integration) 1024 Stiffness & Stability (Vibration & Sagging) 1023 Manufacture and assembly (materials, fabrication, weight) 1023 Cost1023 Total:

Further Work Design & Analysis of intercepts and thermalisation Select Concept (order material?) Define Pipe ID/OD Define Shield Geometry with Vacuum Vessel Design & Analysis of flexure supports Detailed Design & Drawings Pipe Diameter Calculations for Review