1. 9 June 2006MICE CM-15 Fermilab1 Progress on the MICE Cooling Channel and Tracker Magnets since CM-14 Michael A. Green Lawrence Berkeley Laboratory

2. 9 June 2006MICE CM-15 Fermilab2 MICE Channel with the Trackers Drawing by S. Q. Yang, Oxford University Tracker Module 1 Tracker Module 2 AFC Module 1 AFC Module 3 AFC Module 2 RFCC Module 1

3. 9 June 2006MICE CM-15 Fermilab3 Summary of the MICE Magnet Changes since CM-14 The baseline magnet lattice has not been changed. There have been no changes in the AFC magnet and the coupling magnet design, but discussions with vendors suggest that some changes may be needed. The tracker solenoid conductor is at LBNL. The order for two tracker solenoids will soon go out to the vendor. See Steve Virostek’s talk. As a result of discussions with the cooler vendor, a method of mounting the cooler to the magnet has been developed that will allow the coolers to snapped-on the magnet. A cool down analysis and operation scenario has been done.

4. 9 June 2006MICE CM-15 Fermilab4 MICE Magnet and Power Supply Progress

5. 9 June 2006MICE CM-15 Fermilab5 The Focusing Magnet AFC Magnet October 27, 2005 Aspects of the AFC Magnet The cooling of the AFC magnet will be from liquid on the outside of the coils. The magnet will be designed pressure vessel code. The HTS leads will be located in the cryostat vacuum space. The copper lead design current is 250 A. The AFC magnet cold mass support system is designed for 70 tons in the longitudinal direction. Drawing by S. Q. Yang, Oxford University

6. 9 June 2006MICE CM-15 Fermilab6 Focusing Magnet Progress A basic magnet design has been in place for some time. The cold mass support force has been increased to 70 tons. Work on the interfaces with the absorber and coolers will continue. Work has started on an AFC magnet specification. A conductor specification will be written soon. Preliminary cost estimates are being obtained.

7. 9 June 2006MICE CM-15 Fermilab7 The Coupling Magnet The cooling of the coupling magnet May change from liquid helium on the outside of the coils to liquid helium in tubes attached to the coils. This changes some of the pressure vessel code design issues. The HTS leads will be located in the cryostat vacuum space. The copper lead design current is 230 A. The magnet cold mass support system is designed for a longitudinal force of 50 tons. Aspects of the Coupling Magnet Quarter Section of RFCC Module Drawing by S. Q. Yang, Oxford University

8. 9 June 2006MICE CM-15 Fermilab8 Coupling Magnet Progress A basic magnet design has been in place for some time. Detailed engineering will start before the next MICE meeting. Work on the interfaces with the RF cavities and coolers will continue. The coupling magnet specification will be written within two months. A conductor specification will be written soon.

9. 9 June 2006MICE CM-15 Fermilab9 End Coil 2 Center Coil Match Coil 1 End Coil 1 Match Coil 2 Coil Cover Liquid Helium Space 490 mm 690 mm 2544 mm Coil Spacer Tracker Solenoid Cold Mass Courtesy of S. Q. Yang, Oxford University

10. 9 June 2006MICE CM-15 Fermilab10 Tracker Magnet Cold Mass, Coolers Cryogenic Distribution System Magnet Cooler Condenser Box Cold Mass Support Helium Gas Pipe Liquid Helium Pipe Cold Mass Assembly Magnet Leads Courtesy of S. Q. Yang, Oxford University

11. 9 June 2006MICE CM-15 Fermilab11 Tracker Magnet Progress The superconductor for the tracker magnet was delivered to LBNL in early May. The magnet RFP was issued. Five vendors responded with proposal. The vendor for the magnet is expected to be selected before July 1st. Details on the progress on the tracker solenoid will be reported to the collaboration by Steve Virostek.

12. 9 June 2006MICE CM-15 Fermilab12 Power Supply Specification The power supply design current is +300 A at ±10 V. This is a two quadrant power supply with current regulation of better than ±0.01 percent over a current range from 50 A to 275 A. The highest currents are in tracker coils. There will be be at least six of these power supplies. The small power supply design current is ±50 A at ±5 V. This is a four quadrant power supply with current regulation of better than ±0.03 percent over a range of currents from 5 to 45 A. There will be at least four of these power supplies. Power supply specifications will be written before CM-16.

13. 9 June 2006MICE CM-15 Fermilab13 Worst Case Magnetic Fields and Cooler Location

14. 9 June 2006MICE CM-15 Fermilab14 Axial Field outside around the Tracker Cooler Location B = 0.085 to 0.145 T From Holger Witte at Oxford University VLPC Cooler Location B = 0.02 to 0.045 T P = 200 MeV/c,  = 420 mm

15. 9 June 2006MICE CM-15 Fermilab15 Radial Field outside around the Tracker Cooler Location B = 0.085 to 0.145 T From Holger Witte at Oxford University VLPC Cooler Location B = 0.02 to 0.045 T P = 200 MeV/c,  = 420 mm

16. 9 June 2006MICE CM-15 Fermilab16 Radial Field outside the AFC Module Magnet & Absorber Cooler Location B = 0.35 to 0.5 T From Holger Witte at Oxford University P = 200 MeV/c,  = 420 mm

17. 9 June 2006MICE CM-15 Fermilab17 Worst Case Field Map for AFC Module From H. Witte & J. Cobb Oxford University P = 240 MeV/c,  = 420 mm

18. 9 June 2006MICE CM-15 Fermilab18 Axial Field outside the RFCC Module Cooler Location B = 1.0 to 2.0 T From Holger Witte at Oxford University Rotary Valve Location B = ~0 to 0.2 T P = 200 MeV/c,  = 420 mm

19. 9 June 2006MICE CM-15 Fermilab19 Worst Case B Map outside Coupling Magnet P = 240 MeV/c,  = 420 mm

20. 9 June 2006MICE CM-15 Fermilab20 PT415 Pulse Tube Displacer <0.08 T perpendicular Displacer <0.3 T parallel Displacer Motor <0.08 TValve Motor <0.1 T Regenerator <1.5 T Places on the Cooler where B is a Concern

21. 9 June 2006MICE CM-15 Fermilab21 Comments on the Magnet Coolers and their Location The field at the coolers for the tracker magnet is about ~0.1 T. If the coolers are moved out about 0.1 meters, GM coolers could be used for this magnet. Pulse tube coolers have been selected for this magnet The field at the cooler cold head for the AFC module is about 0.3 to 0.5 T. This is too high for using a GM cooler without a large iron shield. Pulse tube coolers with shielded rotary slide valves will be used. The field at the cooler head for the RFCC module is ~1.5 T. This is too high for a GM cooler. A pulse tube cooler with a remote shielded rotary slide valve will be used.

22. 9 June 2006MICE CM-15 Fermilab22 The PT-415 Pulse Tube Cooler and Its Connection to the Magnets

23. 9 June 2006MICE CM-15 Fermilab23 PT415 Pulse Tube Cooler in its Test Stand Rotary Valve Surge Tank Test Cryostat for Machine

24. 9 June 2006MICE CM-15 Fermilab24 6 5 4 3 2 SECOND STAGE TEMPERATURE K Operating Points of the PT415 Cooler The measured test data is from Tom Pointer of Florida State University.

25. 9 June 2006MICE CM-15 Fermilab25 PT415 Cooler Rotary Valve and Motor Rotary Valve Motor Rotary Valve

26. 9 June 2006MICE CM-15 Fermilab26 Snap-in Coolers on the Magnets Since the magnets will be cooled down with liquid cryogens, the pulse tube coolers can be installed in the magnets just before they are cooled down. The condenser is attached to the second stage of the PT cooler. (This is included in the price of the cooler.) The PT cooler is connected directly into the LHe space of the cryostat. The PT cooler will reduce the cooler neck heat leak over a factor of 5. The PT coolers can be removed without warming up the magnets. A new cooler can be installed and cooled down without warming the magnets

27. 9 June 2006MICE CM-15 Fermilab27 2nd Stage Cold Head Helium Condenser for a Snap-on Cooler (Q/A = ~40 W m -2 )

28. 9 June 2006MICE CM-15 Fermilab28 Cryogen Magnet Cool Down Cost The cool down efficiency is assumed to be 80 percent The cool down labor cost with overhead is assumed to be £400.

29. 9 June 2006MICE CM-15 Fermilab29 Should the magnet coolers be shut off during an ISIS shut down? The cost of electricity and cooling is assumed to be £0.06 per kW hour. Each cooler uses 10.5 kW. The focusing magnet uses 2 coolers at an hourly coast of £1.26. The break even time is 725 hours. The coupling magnet uses 1 cooler at an hourly rate of £0.63. The break even time is 1916 hours. The tracker magnet uses 3 coolers at an hourly rate of £1.89. The break even time is 731 hours. One is unlikely to shut down the coolers for a shut down of less than three months.

30. 9 June 2006MICE CM-15 Fermilab30 Some Concluding Comments Progress is being made on all of the MICE magnets. The order for the tracker solenoid will soon be let. The power supply specification must be written in the next 3 months. Cooler specifications must also be written within the next 6 months. The use of pulse tube coolers is dictated by magnetic fields on the cooler cold heads. The use of pulse tube cooler permits snap-on cooler installation. A magnet cool down analysis has been done.