1. MICE CC Magnet Cryostat Design Overview Derun Li Center for Beam Physics Lawrence Berkeley National Laboratory MICE CC Cryostat Design Review LBNL, February 29, 2012 MICE CC Magnet Cryostat Design, LBNL (Feb. 29th 2012)

2. 2 RFCC Modules in MICE Channel RFCC Module #1 RFCC Module #2 2MICE CC Magnet Cryostat Design, LBNL (Feb. 29th 2012)

3. RFCC Module Overview RF Cavities Coupling Coil 3MICE CC Magnet Cryostat Design, LBNL (Feb. 29th 2012) Tuner arms Couplers

4. RFCC Module Overview The MICE RFCC Module has been designed by LBNL and our collaborators; The MICE RFCC Module has been designed by LBNL and our collaborators; The MICE cooling channel incorporates two RFCC modules to be provided by LBNL; The MICE cooling channel incorporates two RFCC modules to be provided by LBNL; Each RFCC module consists of a single superconducting Coupling Coil magnet integrated with four tunable 201 MHz normal conducting RF cavities and a vacuum vessel; Each RFCC module consists of a single superconducting Coupling Coil magnet integrated with four tunable 201 MHz normal conducting RF cavities and a vacuum vessel; The Coupling Coil design was developed by the Harbin Institute of Technology (HIT) in China (a MICE collaborator), in collaboration with LBNL; The Coupling Coil design was developed by the Harbin Institute of Technology (HIT) in China (a MICE collaborator), in collaboration with LBNL; A third Coupling Coil magnet (first delivered) for MuCool will be sited in the MTA at Fermilab; A third Coupling Coil magnet (first delivered) for MuCool will be sited in the MTA at Fermilab; The CC magnet is the largest of the three types of magnets in MICE channel in terms of diameter and stored magnetic energy at full current. The CC magnet is the largest of the three types of magnets in MICE channel in terms of diameter and stored magnetic energy at full current. 4MICE CC Magnet Cryostat Design, LBNL (Feb. 29th 2012)

5. The Coupling Coil Magnet MICE CC Magnet Cryostat Design, LBNL (Feb. 29th 2012)5

6. The CC Magnet Overview The coupling magnet is the largest of the three types of magnets in MICE both in terms of diameter and stored magnetic energy at full current; The coupling magnet is the largest of the three types of magnets in MICE both in terms of diameter and stored magnetic energy at full current; The CC magnet assembly consists of a single coil (cold mass with quench protection and cooling circuit) that fits into a cryostat vacuum vessel;The CC magnet assembly consists of a single coil (cold mass with quench protection and cooling circuit) that fits into a cryostat vacuum vessel; The CC magnet is designed to operate in the MICE cooling channel where the fields from SS and AFC magnets can interact with the magnet;The CC magnet is designed to operate in the MICE cooling channel where the fields from SS and AFC magnets can interact with the magnet; Tight spacing determined by adjacent RF couplers for 201-MHz cavities;Tight spacing determined by adjacent RF couplers for 201-MHz cavities; The inner diameter of the CC magnet mainly determined by the diameter of the RF cavities and the vacuum vessel that must go around the cavities;The inner diameter of the CC magnet mainly determined by the diameter of the RF cavities and the vacuum vessel that must go around the cavities; The CC magnet is to be cooled by 3 cryocoolers that provide up to 1.5 W at 4.2 K /ea;The CC magnet is to be cooled by 3 cryocoolers that provide up to 1.5 W at 4.2 K /ea; The magnet is designed to minimize heat leak, maximize the magnet operating temperature margin.The magnet is designed to minimize heat leak, maximize the magnet operating temperature margin. 6MICE CC Magnet Cryostat Design, LBNL (Feb. 29th 2012)

7. The CC Magnet Overview (cont’d) QP for the CC magnet is passive, protected by cold diodes and resistors across sections of coil and quench back from the 6061 aluminum mandrel: QP for the CC magnet is passive, protected by cold diodes and resistors across sections of coil and quench back from the 6061 aluminum mandrel: – Original design has 8 sub–division to reduce quench voltages (MIT presentations) The CC magnet cold mass support adopts a self-centering support system consisting of eight tension bands that the magnet center does not change as the magnet is cooled down:The CC magnet cold mass support adopts a self-centering support system consisting of eight tension bands that the magnet center does not change as the magnet is cooled down: —The support system is designed to carry a sustained longitudinal force up to 500 kN (50 tons) in either direction during anticipated operation and failure modes The magnet could be powered a single bi-polar power supply: The magnet could be powered a single bi-polar power supply: – Current range: -240 A to +240 A; voltage range: -10 V to +10 V 7MICE CC Magnet Cryostat Design, LBNL (Feb. 29th 2012)

8. Main Parameters of CC Magnet MICE CC Magnet Cryostat Design, LBNL (Feb. 29th 2012)8 Parameters 240 MeV/c and b= 420 mm 200 MeV/c and b= 400 mm Operation modes FlipNon-flipFlipNon-flip Coil Length (mm) 281281 Coil Inner Radius (mm) 750.5750.5 Coil Thickness (mm) 104104 Number of Layers 9696 No. Turns per Layer 166166 Magnet Self Inductance (H) 595.590595.590 Magnet J (A mm –2 ) 114.6108.1 95.590.1 Magnet Current (A) 210.1198.2 175.1165.2 Stored Energy (MJ) 13.211.7 9.18.1 Peak Induction in Coil (T) 7.4777.054 6.2315.879 Coil Temperature Margin (K)  0.77  1.1  1.6  1.8

9. SC Conductors MICE CC Magnet Cryostat Design, LBNL (Feb. 29th 2012)9 Insulated dimension 1.00mm x 1.65mm Cu to S/C Ratio 4.0 ± 0.5 Cu RRR >70 No. Filaments 222 Filament Diameter ~41  m Filament twist Pitch 19 mm ± 6 Ic (4.2K, 5T) > 760 A n > 35 @ 5T Length  260 km

10. The Magnet & Cryostat Overview MICE CC Magnet Cryostat Design, LBNL (Feb. 29th 2012)10 Three cryocoolers demountable windows Welded flanges

11. Heat Load Calculations MICE CC Magnet Cryostat Design, LBNL (Feb. 29th 2012)11 Heat loads from 300K to 60K (W) Copper leads from 300 K 19.30 Cold mass supports (intercept T=72-77 K) 11.215 Radiation Heat to the Shields 8.47 Instrumentation wires 0.092 He Cooling Tubes 2.91 Level sensor tube 0.85 Cooler SS sleeves 9.73 Neck shield supports 0.88 Heat shield supports 0.37 (longer support) Sub-total (calculated) 53.817 Total Heat Load with 50% Contingency 80.7255 Total Heat Load with 100% Contingency 107.634 Heat load from 60K to 4.2K (W) Current design HTS current leads (T = 64 K) 0.15 4.2K Cold mass supports (T=73-78K) 0.478 Radiation heat to 4.2K cold mass (Shield Tave = 70K) (W) (MLI layer :20) 0.832 Instrumentation Wires 0.00307 He cooling tubes 0.09 Level sensor tube 0.03 Cooler SS sleeves (testing data) 0.60 14 Superconducting Splices at 10 nW per splice and 210 A 0.01 Total with 50% Contingency 3.2897 Total with 100% Contingency 4.3862

12. 3D Cryostat Model MICE CC Magnet Cryostat Design, LBNL (Feb. 29th 2012)12 Coil cold mass Cold mass support Neck shield Main shield Shield support

13. Major Sub-Assemblies MICE CC Magnet Cryostat Design, LBNL (Feb. 29th 2012)13

14. Major Assembly: Cold-Mass (1) Cold-mass from China: Cold-mass from China: – Coil and welded cover plate Weld cooling tubes, fill-in line and thermal siphon line Weld cooling tubes, fill-in line and thermal siphon line Support brackets Support brackets Vacuum potting Vacuum potting Quench protection circuits Quench protection circuits & installation & installation Lead stabilization Lead stabilization Diagnostic sensors Diagnostic sensors Top reservoir Top reservoir *some of the images presented here have not been updated yet MICE CC Magnet Cryostat Design, LBNL (Feb. 29th 2012)14

15. Major Assembly: Cooling Circuit (2) Cooling circuit assembly Cooling circuit assembly MICE CC Magnet Cryostat Design, LBNL (Feb. 29th 2012)15

16. Major Assembly: Shielding (3) MICE CC Magnet Cryostat Design, LBNL (Feb. 29th 2012)16

17. Major Assembly: Vacuum Vessel (4) MICE CC Magnet Cryostat Design, LBNL (Feb. 29th 2012)17

18. Current Status and Plan Cold-mass testing in preparation at LBNL Cold-mass testing in preparation at LBNL – Scheduled to ship to Fermilab by end of April 2012 – Remaining tasks at LBNL: Welding of cooling tubes Welding of cooling tubes QP circuit design, fabrication and installation (with MIT) QP circuit design, fabrication and installation (with MIT) Vacuum potting and high pot testing Vacuum potting and high pot testing Cold-mass testing at Fermilab Cold-mass testing at Fermilab – Summer 2012 Superconductors ordered Superconductors ordered Coil winding review at QH Coil winding review at QH – Mid-late April 2012 MICE CC Magnet Cryostat Design, LBNL (Feb. 29th 2012)18

19. Current Status and Plan (cont’d) Near term plan Near term plan – Preparation for the cold-mass testing at Fermilab – Finalize QP and lead stabilization design (MIT) Generation of fabrication drawings Generation of fabrication drawings Parts fabrication Parts fabrication – Updating and generation of the fabrication drawings of the cryostat parts – Deliver the drawings to QH for fabrication Estimated fabrication time for the parts: four months Estimated fabrication time for the parts: four months 2 nd and 3 rd coil winding at QH 2 nd and 3 rd coil winding at QH – Coil winding (estimated winding time: 3-4 months/ea) – Cover plate welding at HIT (estimated time: 4 weeks) – Shipping the cold-mass to US (3 weeks) Testing and cryostating in the US Testing and cryostating in the US MICE CC Magnet Cryostat Design, LBNL (Feb. 29th 2012)19

20. Magnet & Cryostat Design Details Cryostat Mechanical Design Details Cryostat Mechanical Design Details – Allan DeMello Cryostat Thermal & Stress Analysis Cryostat Thermal & Stress Analysis – Heng Pan Cooling Circuit Design Cooling Circuit Design – Steve Virostek Quench Protection Analysis Quench Protection Analysis – Brad Smith (MIT) Lead Stabilization Lead Stabilization – Alexy Radovinsky (MIT) Instrumentation Plan Instrumentation Plan – Steve Virostek MICE CC Magnet Cryostat Design, LBNL (Feb. 29th 2012)20