MICE/MuCool Coupling Magnets to 22 ICST/HIT MICE/Muool Coupling Magnets Progress Li Wang for MICE Group Institute of Cryogenics and Superconductivity Technology Harbin Institute of Technology, Harbin, China

to 22 ICST/HIT MICE/MuCool Coupling Magnets Recent Progress Test coils Winding of large test coil: to be done around Oct.25th Fabrication of quench protection assembly for large coil: to be done by Oct.25th Tests for SC joint soldering strength, SC wire bending radius: done Cryo-test system: Test dewar for diodes: done Large cryostat: under fabrication Small cryostat: done Cryo-valves & bayonets, transfer lines: under assembly Updated design of MICE/MuCool coupling magnets Cold mass assembly, drop-in mode cryocooler, cold mass support assembly, heat shields, vacuum chamber, etc.: under going Progress since CM21 at Daresbury in June 2008:

to 22 ICST/HIT MICE/MuCool Coupling Magnets Test Coils Test coils Due to relatively high magnetic field (peak field above 7.4T in the coil), largest diameter of the coil in MICE (ID 1.5m), high strain and stress in the coupling coil, two test coils were designed and fabricated in order to validate design methods and winding skills, and to practice the worst case in the coupling coil. The test coils will be powered to a higher current than 210A and The 2nd test coil will be cooled down using the ICST refrigerator in a cryostat suitable for the training the large test coil and the coupling magnets. Small coil:  350mm x 285 mm, 20 layers, 166 turns/layer, 500 A To test and debug the winding machine and the wire tension device, to validate the winding skills such as wet lay-up winding technology, layer-to-layer transition, quench protection lead bringing out, welding, elec-insulating and winding of SC splices, to produce enough field so that the magnet can be used for cold diode tests and other sorts of tests to be done in a magnetic field at 4.2 K. Large coil : a full diameter but one-quarter long prototype coil, 96 layers, 42 turns/layer, 350 A To be expected to be tested under the equivalent or greater strain state than the coupling coil would encounter during cool down and in magnetic field, to be performed a full scale test of the coupling coil cold diode and resistor quench protection system with the test coil sub-divided into four circuits, to test the SC joint soldering technique, to gain training process experience etc.

to 22 ICST/HIT MICE/MuCool Coupling Magnets Basic Parameters Small coil Large Coil Coupling Coil Coil Length (mm) Coil Inner Radius (mm) Coil Thickness (mm) Number of Layers2096 No. Turns per Layer Magnet J (A mm-2)* Magnet Current (A)*210 Magnet Self Inductance (H) Peak Induction in Coil (T) Magnet Stored Energy (KJ) K Temp. Margin (K) Length of conductors per coil (km)

to 22 ICST/HIT MICE/MuCool Coupling Magnets Load Lines 401A 575A 210A

to 22 ICST/HIT MICE/MuCool Coupling Magnets Small Coil The small coil winding, welding of its cold mass assembly and the cryostat construction for its cryo-test have been done around this June. The connection to the cryo-test system is expected to be finished around the middle of this Nov. ～ DN600*1500 Power leads Vacuum vessel Small coil Cooling tubing Bayonets

to 22 ICST/HIT MICE/MuCool Coupling Magnets Large Coil Winding The winding procedure was approved by LBNL around the middle of this Sept. The large coil winding started on Sept.20 th and will be finished around Oct.25 th. There are 4 SC splices in the coil, and 4-sectioned cold diode and resistor quench protection system is applied. The fiberglass cloth is wrapped every 12 layers of SC wires. The Catalyst 23LV (low viscosity) is used.

to 22 ICST/HIT MICE/MuCool Coupling Magnets For small coil, 2-section of quench protection circuit consisting of cold diodes and resistors is to be applied. For large coil, 4-section is to be used. The resistor is sized as 6mΩ. The quench protection assembly is under fabrication. Quench Protection Assembly for Test Coils QPAssembly for large coil

to 22 ICST/HIT MICE/MuCool Coupling Magnets Tests for SC Joints There will be 11~12 SC splices in one coil. The up-down overlap joint with 96Sn-3.5Ag-0.5Cu soft solder is to be applied at the ends of the large test coil and the coupling coils. The resistance per splice made by ICST has been tested < 5 n  even under the magnetic field of 5T at 4.2K. The SC splice tensile strength was tested at LN2 temperature, which is >500MPa. Test facility Up-down joints

to 22 ICST/HIT MICE/MuCool Coupling Magnets Splice Joint length （ mm ） Ultimate strength （ MPa ） No No No Splice Joint length （ mm ） Ultimate strength （ MPa ） No No No The tensile test results of SC splices at 77 K The tensile test results of SC splices at 300 K Sample Ultimate strength （ MPa ） Yielding strength （ MPa ） ε(%) No No No The tensile test results of SC wires at 300 K

to 22 ICST/HIT MICE/MuCool Coupling Magnets Large coil Small coil MuCool/MICE coils Cryo-Test System To provide the cooling capacity at 4.2K for performance tests of test coils and MICE/MuCool coils It mainly consists of the TCF20s refrigerator, 500L LHe dewar, control valve box, cryostats for test coils and MuCool/MICE coils, transfer lines, GHe recovery/purification/storage system, vacuum pumping system etc. Most parts have been fabricated, and are under assembly. 500L LHe has been filled into the 30m 3 GHe tank on Oct. 10th. The cryo-test system is expected to be ready for coil test around the middle of this Nov.

to 22 ICST/HIT MICE/MuCool Coupling Magnets Control valve box Cryo-valves

to 22 ICST/HIT MICE/MuCool Coupling Magnets Large cryostat ～ DN2100* S.S. Bayonets Φ1500/MICE/MUCOOL coil Power leads QPAssembly for large coil Large cryostat was contracted out at the early of this Sept., and is scheduled to be done at the end of Oct.

to 22 ICST/HIT MICE/MuCool Coupling Magnets Transfer lines

to 22 ICST/HIT MICE/MuCool Coupling Magnets Test dewar for diodes Due to high magnetic field of the coupling coil, performance (such as forward voltage etc.) of cold diodes at low temperature and at high magnetic field (2~3T) must be tested in order to design quench protection circuit, charging and fast discharging system before they are installed inside the magnet. The test at low temperature is planned by the end of Oct.

to 22 ICST/HIT MICE/MuCool Coupling Magnets Updated Design of MICE/MuCool Coupling Magnets Cold mass supports The cold mass support will be a double-band type considering 500kN force in the longitudinal direction at the worst case, 2g~3g shipping load in any direction, heat leak restriction, and available space inside the cryostat. Vacuum chamber of cryostat The design of the outer vacuum chamber of magnet cryostat and warm end connections of cold mass supports will be modified according to final double- band structure of cold mass supports and RFCC module interface. Drop-in mode cryocoolers and cooling connections The drop-in mode cryocoolers are to be adopted for the coupling magnets considering easy assembly and disassembly during long distance transportation, and cooler maintenance. The cooling connections between the cold heads of the coolers and the current leads, and between the cold heads and the heat shields have to be updated accordingly.

to 22 ICST/HIT MICE/MuCool Coupling Magnets Double-band support design Drop-in mode cryocoolers and cooling connections

to 22 ICST/HIT MICE/MuCool Coupling Magnets Original design New design Cold mass assembly In order to mount the strong cold mass support bases, to reduce the possibility of SC wires damaged by cold mass welding process, and to provide space for mounting 8- section quench protection diodes and resistors etc., the cold mass assembly design of the coupling magnet is to be updated, as well as the quench protection assembly.

to 22 ICST/HIT MICE/MuCool Coupling Magnets  Large test coil winding By 10/25  Performance test for diodes at low temp. By 10/31  Fabrication of test cryostat for large coil By 10/31  Construction of test station for small coil By 11/15  Assembly of large coil cold mass By 11/22 to weld cover plate/cooling tubing/helium vessel, leakage check, to install quench protection circuit and instrumentation, etc.  Cryo-test for large coil Expected to start on 11/24  To update design of MuCool/MICE coupling magnets By 11/30  Review on test coils and updated design of MuCool/MICE coupling magnets 12/06 to 12/08 WBS for Test Coils and the MuCool Coil

to 22 ICST/HIT MICE/MuCool Coupling Magnets  Fabrication of MuCool coil mandrel By 01/05/09  Winding of MuCool Coil By 02/28/09  Assembly of MuCool coil cold mass By 03/31/09 to weld cover plate/cooling tubing/helium vessel, leakage check, to install quench protection circuit and instrumentation, etc.  Cryo-test of MuCool coil cold mass By 04/30/09  Assembly of MuCool magnet cryostat By 07/09/09  Cryo-test of MuCool magnet By 07/31/09  Two MICE magnets By 12/31/09 Status of Funds  HIT has provided 1.5 million Yuan (RMB) funding for the MICE CC project till this July, which was spent on construction of two test coils and cryo-test system, and will be used for fabrication of the MuCool coupling magnet.  ICST will submit another ~1.0 million Yuan (RMB) funding application proposal to the HIT for fabrication of two MICE magnets at the early of 2009.

MICE/MuCool Coupling Magnets to 22 ICST/HIT Click to edit company slogan. Icst.hit.edu.cn