Thermal Screen Material Selection Niklas Templeton Thermal Screen

Thermal Screen Material Selection Niklas Templeton

Thermal Screen Gate Review • Cooling Circuit & Cryo Safety • Panel Material • Pipe Panel Connections • Concept Variant Analysis • Clamp Options

Cooling Circuit & Cryo Safety BS-EN-13480 -3 -2017 Metallic Industrial Piping Design & Calculation Preliminary calculation for pipes under internal pressure does not include thermal stress, self weight, etc. He Out He In Calculation Pressure: 25 Bar Internal Diameter: 15 mm Minimal Wall Thickness (mm) Straight Pipe With Bends (R > 2. 5. Do) SS 316 Cu ETP Al 6063 0. 12 0. 46 0. 14 0. 52 0. 18 t ≥ 1 mm is acceptable No. of joints & connections are more critical for ease of integration, risk and need for qualification. Transitions Welds SS 316 0 4 Cu ETP 6 4 Al 6063 2 4 Top-Bottom Connection

Panel Material Cu OFE (2 mm) Al 1100 (3 mm) 168. 6 51. 1 76. 7 Specific Heat 300 -50 K (k. J) 13, 717 9, 254 13, 881 Thermal Conductivity @ 50 K k 50 K (W/m. K) 864 369 Relative Conductivity (W/K) 1. 73 0. 74 1. 11 1 4 3 Cost Evaluation • • Copper shield is significantly heavier which impacts stiffness, stability & ease of assembly Specific Heat difference is negligible Thermal Conductivity (W/m. K) Mass (kg) 1 E+04 1 E+03 Al 1100 Al 6061 T 6 1 E+02 Cu OFE RRR 50 Cu OFE RRR 100 SS 316 1 E+01 1 E+00 0 • Thermal performance of copper is greater however simulations have shown all solutions to be acceptable 50 100 150 Temperature (K) 200 250 300

Pipe Panel Connections 1. Cu ETP Pipe – Cu OFE Panel All options feasible for thermal performance but differ in: • Ease of Fabrication • Ease of Assembly • Cost • Need for Qualification Pipe Panel Pipe-Panel Connection 1 Cu ETP Cu OFE Brazed 2 Al 6063 Al 1100 Welded 3 SS 316 Al 1100 Clamped 2. Al 6063 Pipe – Al 1100 Panel Comment Clamp options presented later 4 SS 316 Al 1100 Cu Straps Brazed/Bolted Additonal Cooling Circuit Support Required 5 SS 316 Cu OFE 3. SS 316 Pipe – Al 1100 Panel 4. SS 316 Pipe – Al 1100 Panel Brazed 5. SS 316 Pipe – Cu OFE Panel

Concept Variant Analysis • Values are initial estimates. Table is for discussion purposes. Weighting 40% 30% 5% 20% Cryo Safety Pipe-Panel Connect. Pipe Panel Pipe-Panel Connection Ease of Fabrication Ease of Assembly Qualified 1 Cu ETP Cu OFE Brazed 1 4 4 2 5% Cost 100% Weighted Score /4 1 2. 25 2 Al 6063 Al 1100 Welded 2 4 4 3. 2 3 SS 316 Al 1100 Clamped 4 3 3 4 4 3. 65 4 SS 316 Al 1100 Cu Straps Brazed/Bolted 4 3 2 4 3 3. 55 5 SS 316 Cu OFE 4 4 4 2 1 3. 45 Brazed

Clamp Options 1. Clamp Welded – Panel Welded Maximise TCC between pipe & panel 2. Clamp Welded – Panel Bolted Ease panel assembly Clamp-Panel interface is less critical as it’s Al-Al Fasteners could cause MLI/Integration issue 3. Clamp Bolted – Panel Bolted Cooling Circuit fabricated from ~12 parts Ease of fabrication Ease of Assembly Less qualified Potential MLI/Integration Issue 4. Clamp Bolted – Panel Welded Ease of fabrication Less qualified Cooling Circuit fabricated from 3 parts

Additional Slides

CTE Comparison T (K) 4 20 40 60 80 100 120 140 160 180 200 220 240 260 273 293 Copper 0. 324 0. 322 0. 314 0. 300 0. 282 0. 259 0. 234 0. 207 0. 178 0. 148 0. 117 0. 086 0. 054 0. 033 0. 000 (L 293 -LT)/L 293) (%) 2024 Alum 7075 Alum 0. 396 0. 419 0. 394 0. 417 0. 387 0. 408 0. 372 0. 392 0. 351 0. 370 0. 325 0. 343 0. 295 0. 312 0. 262 0. 278 0. 227 0. 241 0. 190 0. 202 0. 151 0. 161 0. 119 0. 070 0. 076 0. 043 0. 047 0. 000 304 SS 0. 306 0. 303 0. 294 0. 281 0. 265 0. 245 0. 222 0. 195 0. 168 0. 140 0. 113 0. 083 0. 052 0. 031 0. 000 1 2 3 4 5 Pipe Panel Cu ETP Al 6063 SS 316 Cu OFE Al 1100 Cu OFE CTE Comparison Max L d. L Pipe d. L Panel (mm) 7. 9 9. 6 2440 7. 4 9. 6 7. 4 7. 9 diffence (mm) 0. 0 2. 2 0. 5

Pipe Panel Connections • • • SS 316 Pipes pre-assembled to Al block Pipes are pre-loaded with clamp Al block welded Pipe-block is integrated into cooling circuit Al blocks are fastened to panel • Validation see ‘EDMS No. 1977794’ – Thermal Characterisation of Stainless Steel Tube in Alluminium Block for Applications in Thermal Shield, A Nuñez Chico • TCC > 500 W/m 2 K https: //edms. cern. ch/ui/file/1977794/1/Measurement _of_temperature_to_estimated_TCC_docx_cpdf. pdf

Proof of Principal Analysis • Steady State Thermal Analysis • Non-Linear Material properties • Pipe Convection: 400 W/m 2 @ 50 K • Thermal Contact Conductance: 500 W/m 2 K • Heat Loads (see table) Heat Source Heat Load (W) FPC 36. 0 HOM Coax 9. 0 Blades 7. 7 CWT 5. 0 Tuner 7. 6 Instrumentation 8. 0 Screen Supports 2. 0 Bi. Phase Support 2. 5 Pick-ups 2. 0 Radiation QTY 2 4 4 4 2 1 4 2 2 Flux (W/m 2) Area (m 2) 1. 2 8. 9 Total: Total (W) 72 36 30. 8 20 15. 2 8 8 5 4 10. 7 209. 7 Thermal Screen Heat Load Estimates v 0. 1. xlsx https: //indico. cern. ch/event/742082/contributi ons/3085091/attachments/1734407/2805340/ HL_LHC_Collaboration_2018. pdf

Proof of Principal Analysis • Preliminary analysis shows that design changes minimise temperature gradient across the shield • Max d. T panels: ~2 K • Max d. T Pipe, panels and braids: ~20 K Shield Temperature Panel Temperature

Specification & Requirements Specifications • LHC Cryo Safety • Design Pressure: 25 Bar (absolute) • Operating Temperature: 40 -60 K • Pipe ID: 15 mm • Heat Load Capacity > 220 W • Maximum T at intercepts: 80 K Requirements • Minimise Thermal Stress – Homogenous T across panels – Stress relief between dissimilar materials • Modular pre-fabricated parts for assembly around top plate • Dressed in 30 layers of MLI

DQW Thermal Screen • OFE Copper Panels cooled with brazed ETP pipe with GHe at 50 K • Intercepts critical cold-warm components • Dressed with 30 layers of Multi Layer Insulation • Minimises conductive & radiative heat leak to cavities • Design validation & optimisation using combined thermo-mechanical analysis Ti-6 Al-4 V Flexure Brackets 316 LN nut plates & stiffeners Cu-SS transition 14/18 mm Cu ETP pipe ~210 kg 2 mm Copper OFE panel Brazed GHe cooling circuit 50 K

RFD Thermal Screen Concept Design • SS 316 Cooling circuit for cryoline integration and pressure safety • ‘Semi-Active’ cooling circuit allows thermalisation direct to pipe (brazed copper braids) • Al 1100 panels give significant cost and weight savings for series production • Increased stiffness • Greater thermal performance • Optimisation & detailed design ongoing ‘Semi-Active’ Cooling Pin-Jointed Bracket Design Cooling Circuit Ø 15/19 316 LN Clamped Pipe. Panel Connections ~100 kg 3 mm Al 1100 Panels