MICE/MuCool Coupling Magnets to 07, CM25, RAL/UK WANG, LI MICE/MuCool Coupling Magnet at HIT Technical Progress WANG, Li MICE Group, ICST/HIT Shanghai Institute of Applied Physics, CAS

to 07, CM25, RAL/UK WANG, LI MICE/MuCool Coupling Magnets Contents Mandrels and Cover Plates for 3 coupling magnets Conductor Slices from the QiHuan Company Vacuum Chamber & Interface w/RF cavities Heat loads and Available Cooling Capacity Coupling Magnet Double-Band Support

to 07, CM25, RAL/UK WANG, LI MICE/MuCool Coupling Magnets Mandrels and Cover Plates for 3 coupling magnets The 6061-T6 Al mandrel fabrication is changed from welded plates to a forging because the heat treatment process of welded mandrel is hard to realize using currently available ovens in China. 3 forged mandrels and 2 forged cover plates were contracted out to QiHuan Corp. in Beijing at the end of October (Fabrication of one cover plate for the MuCool magnet has been done). The first MuCool mandrel is expected around the middle of February 2010, which means the MuCool coil winding can only start at the end of February 2010 if without having large coil test. The other two MICE mandrels are expected in April or May, There is an additional cost of 100k YuanRMB for the MuCool mandrel. The welded mandrel with cost of 70k YuanRMB has to be abandoned. (This is a potential funding issue.)

to 07, CM25, RAL/UK WANG, LI MICE/MuCool Coupling Magnets Welded Mandrel Already Fabricated Heat treatment is required to make the mandrel strong enough

to 07, CM25, RAL/UK WANG, LI MICE/MuCool Coupling Magnets Strength of forged 6061-T6Al mandrel 遵循中华人民共和国有色金属行业标准 YS/T 《一般工业用铝及铝合金锻件》； Conform to the Chinese standard YS/T on forged Al and Al alloy. 自由锻件（胎膜）的尺寸及偏差符合供需双方签订的图样或合同规定。截面积不大于 mm^2 的自由锻件，室温力学性能符合 YS/T 表 4 的规定。 The material strength at room temp. can reach the value as the below table in YS/T Longitudinal Transverse Radial Thick

to 07, CM25, RAL/UK WANG, LI MICE/MuCool Coupling Magnets Conductor Slices from the QiHuan Company  The training of coil winding technique for QiHuan by ICST was done by the end of this July.  The QiHuan company submitted three 1-meter long conductor splices to be tested at LBNL. All the splices submitted had resistances that were less than 0.6 n  at 1 T. The splice fabricated by ICST were also entirely satisfactory in that they ran from 0.7 to 1.3 n . The change between the ICST splices and the QiHuan splices is not fully understood.  The QiHuan splices were tested in magnetic fields from 0 to 5 T. The 0 field splices had a much smaller resistance because the solder was superconducting at that field. The solder selected was the Sn-Pb eutectic Solder, which tested very well in the splice tests.

to 07, CM25, RAL/UK WANG, LI MICE/MuCool Coupling Magnets Vacuum Chamber & Interface w/RF cavities Discussion among HIT, QiHuan and LBNL recently: ToleranceRequired (Technical Agreement ) Achievable for MICE coupling magnets Achievable for MuCool coupling magnet The longitudinal position of the cryostat center should be the same as the coil center ±0.5 mm±1.0 mm±5.0 mm The coupling solenoid cold mass central axis shall be co- axial with the cryostat vacuum vessel axis ± 0.3 mm± 1.0 mm±5.0 mm The maximum allowable tilt of the cold mass axis (the magnetic axis) with respect to the axis of the warm bore tube ±0.001 radian (±0.057 degree) ±0.004 radian (±0.228 degree) ±0.35 degree Is tolerance is acceptable for the MICE cooling channel? Does the MuCool magnet need to work as back-up for the MICE cooling channel? Higher accuracy means a higher cost for fabrication (doubled price). For now, the cost is till within the budget, but if high accuracy required for MuCool magnet, it is beyond the budget and the procured 304SS materials for MuCool magnet vacuum chamber (~80k Yuan RMB) has to be abandoned (funding issue) ! Too High For MICE

to 07, CM25, RAL/UK WANG, LI MICE/MuCool Coupling Magnets Heat Loads and Available Cooling Capacity at 4.2K HTS current leads ( Warm HTS end T = 64K) (W) K Cold mass supports (intercept T = 80K) (W)0.35 Radiation heat to 4.2K cold mass (Shield T = 100K) (W)0.50 Instrumentation Wires (~120 wires) (W)0.20 Neck tubes with 0.2W from each drop-in cooler (W) Superconducting 10 n , per splice and 210 A (W) 0.01 Sub-Total (W) percent Contingency (W)0.87 Total with Contingency (W)2.60 Is the contingency adequate? A single Cryomech PT415 cooler generates, 1.5W/4.2K, 50Hz with the first stage at 55 K. Greatest uncertainty

to 07, CM25, RAL/UK WANG, LI MICE/MuCool Coupling Magnets Copper leads from 300 K (W)19.3 Cold mass supports (W)9.9 Radiation Heat to the Shields (W)10.0 Instrumentation wires (W)1.2 Neck Tubes and Cooler Tubes (W)8.8 Heat shield supports (W)4.6 Sub-total (W) Percent Contingency (W)27.1 Total Heat Load with Contingency (W)81.2 Heat Loads and Available Cooling Capacity on the Cooler First Stage at 60K Note: A Cryomech PT415, is good for 60W at 55 K for the cooler first stage. Greatest uncertainty

to 07, CM25, RAL/UK WANG, LI MICE/MuCool Coupling Magnets Top he vessel Cooling tubing Heat shield Vacuum vessel Banding Coil End plate Bobbin Cover plate 10mm 18mm Tight space for MLI

to 07, CM25, RAL/UK WANG, LI MICE/MuCool Coupling Magnets RFCC coupler tube CM vacuum vessel MLI Thermal shield Cold mass The tight space will lead to difficulty in cryostat assembly and an increase in the heat leak locally in the five places where the couplers and vacuum pump port come out of the vacuum vessel. The problem is the potential for a larger radiation heat leak at 4.2 K into the cold mass. This has been an ongoing problem.

to 07, CM25, RAL/UK WANG, LI MICE/MuCool Coupling Magnets 300K-60K Band Rod End Pin Thermal Intercept Clevis 60K-4.2K Band Bracket Base Plate Coupling Magnet Double-Band Support

to 07, CM25, RAL/UK WANG, LI MICE/MuCool Coupling Magnets Cold Mass Support Assembly Due to possible shipping loads of 2.5g during long distance transport, the design force of the cold mass support assembly was increased from 127 kN to 200 kN, the single-band support was updated to the double-band support considering tight space and restricted heat leakage requirement through the bands. The small angle (<10 0 due to the magnet design) is another challenge in the cryostat assembly. Angle <10 o

to 07, CM25, RAL/UK WANG, LI MICE/MuCool Coupling Magnets Concluding Technical Comments  The mandrel will be changed from a welded plate mandrel to a forging because of heat treatment of the welded mandrel is a problem. The forging has adequate strength in all directions.  The margins for coil placement in the cryostat need to be reviewed further.  Small insulation spaces around the couplers and on the cryostat inner bore can cause a higher heat leak at 4.2 K. This is still a concern.  The cold mass support design was changed because of the shipping loads. The small angle (<10 o due to the magnet design) is another challenge in the cryostat assembly. The conservative design of the cold mass supports might allow the support angle to be changed.

MICE/MuCool Coupling Magnets to 07, CM25, RAL/UK WANG, LI Click to edit company slogan.