progress on the mice cooling channel and tracker magnets
DESCRIPTION
Progress on the MICE Cooling Channel and Tracker Magnets. Michael A. Green Lawrence Berkeley Laboratory. AFC Module 2. RFCC Module 1. Tracker Module 2. AFC Module 3. AFC Module 1. RFCC Module 1. Tracker Module 1. MICE Channel with the Trackers. Drawing by S. Q. Yang, Oxford University. - PowerPoint PPT PresentationTRANSCRIPT
12 March 2006 NFMCC Meeting, IIT, Chicago 1
Progress on the MICECooling Channel and Tracker
Magnets
Michael A. Green
Lawrence Berkeley Laboratory
12 March 2006 NFMCC Meeting, IIT, Chicago 2
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
RFCC Module 1
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Summary of the MICE Magnet Changessince the last NFMCC Meeting
• The baseline magnet lattice has been changed slightly. There may be other small changes in the tracker magnet system.
• Since the NFMCC meeting, there have been no changes in the AFC magnet and the coupling magnet, but discussions with vendors suggest that changes may be needed.
• The tracker solenoid has been designed and a specification has been written. The RFP will go out soon.
• As a result of discussions with magnet vendors, the magnet design may move toward indirect cooling with LHe in pipes.
• Further work has been done on the worst case longitudinal magnetic forces in MICE.
• The field at the cooler determines what type of cooler to use.
12 March 2006 NFMCC Meeting, IIT, Chicago 4
Courtesy of S. Q. Yang, Oxford University
The MICE AFC Module
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Magnet Mandrel
Safety Window
LH2 Pipes
Liquid Helium Feed Pipe
Gas He Pipe
Hydrogen Window
S/C Coil #1
LH2 Absorber
S/C Coil #2
Coil Cover Plate
The Center of the MICE AFC Module
Courtesy of S. Q. Yang, Oxford University
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The Focusing Magnet
AFC Magnet October 27, 2005
Aspects of the AFC Magnet
The cooling of the AFC magnet will probably change from liquid on the outside of the coils to liquid 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 250 A.
The AFC magnet cold mass support system is designed for 50 tons in the longitudinal direction.
Drawing by S. Q. Yang, Oxford University
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Coupling Magnet
Cavity RF Coupler
Dished Be Window
RF Cavity
Module Vacuum Vessel
Vacuum PumpMagnet Vacuum Vessel
The MICE RFCC Module
Courtesy of S. Q. Yang, Oxford University
12 March 2006 NFMCC Meeting, IIT, Chicago 8
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
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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
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Tracker Solenoid 50 Ton Longitudinal Force Cold Mass Support System
300 K Support End
60 K Support Intercept
Support Band
4 K Support End
Cold Mass Assembly
Courtesy of S. Q. Yang, Oxford University
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Tracker Magnet Cold Mass, CoolersCryogenic Distribution System
Magnet Cooler
Condenser Box
Cold Mass Support
Helium Gas PipeLiquid Helium Pipe
Cold Mass Assembly
Magnet Leads
Courtesy of S. Q. Yang, Oxford University
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Changes in the Cryogenic System
• The high temperature superconductor (HTS) leads may have to operate in a vacuum (depends the on type of lead). The lead vacuum-tight feed through problem is not trivial.
• A number of the vendors suggest that the MICE coils should be cooled indirectly (using liquid helium in tubes). This is OK as long as the tube area is large enough.
• Changing from having a liquid reservoir in the cold mass assembly to liquid helium in tubes will change the pressure vessel code design of the magnet cold mass. The only part of the helium system that comes under the pressure vessel code is the condenser box at the bottom of the magnet coolers.
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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.
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PSPower Supply±10 V, 0 to 300 A
Total Inductance from 304 H to 416 H
PSPower Supply±10 V, 300 A
Coupling MagnetMandrelCold DiodeCold ResistorInductance = 563 H
Focusing and Coupling magnet Hookup
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Power Supply±10 V, 300 A
Power Supply±5 V, ±50 A
PSPSPSPSPSPSPSPower Supply±5 V, ±50 A
Tracker Magnet Hookup
M1 M1M2 M2 E1E1 E2E2 C C
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Coupling Coefficients between CoilsMagnet Circuit Self Inductance and the Mutual Inductances in the Flip Mode
Magnet Circuit Self Inductance and the Mutual Inductance in the Non-flip Mode
Courtesy of H. Witte, Oxford University
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Forces with MICE Magnet Quenches
MagnetBaselineMICE
Both TrackerMagnets Normal
One CouplingMagnet Normal
Three FocusMagnets Normal
Detector 25.5 -0- 40.6 -14.7
End Focusing -18.8 21.4 -40.3 -0-
Coupling -8.8 -15.2 -0- -8.7
Center Focusing 0 0 21.5 -0-
Coupling 8.8 15.2 -7.1 8.7
End Focusing 18.8 -21.4 18.6 -0-
Detector -25.5 -0- -33.3 14.7
See MICE Note 107 with the magnet lattice of August 2004.
The three focusing magnets will quench together.
Both Tracking magnets quench together.Only one coupling magnet will quench.
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“Hey dummy, you reversed the leads 1.”
MagnetBaselineMICE
1 CouplingCoil Reversed
2 CouplingCoils Reversed
3 Focus CoilsReversed
Detector 10.5 10.2 22.0 -11.3
End Focusing -3.0 -3.4 -47.0 3.0
Coupling -15.6 26.8 15.6 -14.1
Center Focusing 0 -43.0 -0- -0-
Coupling 15.6 -15.6 -15.6 14.1
End Focusing 3.0 47.0 47.0 -3.0
Detector -10.5 -22.0 -22.0 11.3
Baseline MICE Lattice as of March 2006, when p = 200 MeV/c and = 420 mm.
The highest forces are in the focusing coils when the coupling coil leads are reversed.
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“Hey dummy, you reversed the leads 2.”
MagnetBaselineMICE
Both M1 CoilsReversed
Both M2 CoilsReversed
SpectrometersReversed
Detector 10.5 -25.4 -6.7 11.9
End Focusing -3.0 38.0 2.0 1.0
Coupling -15.6 12.7 -17.7 -20.8
Center Focusing -0- -0- -0- -0-
Coupling 15.6 8.8 17.7 20.8
End Focusing 3.0 -38.0 -2.0 -1.0
Detector -10.5 25.4 6.7 -11.9
Baseline MICE Lattice as of March 2006, when p = 200 MeV/c and = 420 mm.
The highest forces are in the end focusing coils when the M1 leads are reversed.
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Peak Longitudinal Forces
• The peak longitudinal forces on the focus coils will occur when p = 240 MeV and = 420 mm in the flip mode, with the leads reversed. The peak force is about 68 tons on the end focusing magnets, when one or both coupling magnets are reversed. When the M1 coils are reversed, the peak force on the end focus coils is about 54 tons in the flip mode. The MICE magnet polarity must be checked before going to high momenta (currents in the coils).
• In the non-flip mode the peak force on the focusing magnet is about 46 tons with the leads reversed. Similar forces may be found in the tracker magnets. More work is needed to show what the peak forces are in all of the magnets.
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Axial Field outside around the Tracker
Cooler LocationB = 0.085 to 0.145 T
From Holger Witte at Oxford University
VLPC Cooler LocationB = 0.02 to 0.045 T
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Radial Field outside around the Tracker
Cooler LocationB = 0.085 to 0.145 T
From Holger Witte at Oxford University
VLPC Cooler LocationB = 0.02 to 0.045 T
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Radial Field outside the AFC Module
Magnet & AbsorberCooler LocationB = 0.35 to 0.5 T
From Holger Witte at Oxford University
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Axial Field outside the RFCC Module
Cooler LocationB = 1.0 to 2.0 T
From Holger Witte at Oxford University
Rotary Valve LocationB = ~0 to 0.2 T
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Comments on Cooler Location and theType of Cooler to be used
• 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 can be used for this magnet.
• The field at the coolers 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. Use pulse tube coolers with shielded rotary slide valves.
• The field at the cooler for the RFCC module is ~1.5 T. This is too high for a GM cooler. Use a pulse tube cooler with a remote shielded rotary slide valve.
• The VLPC coolers can be GM coolers, because the field is less than 0.05 T
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Concluding Comments
• It appears that indirect cooling (liquid helium in tubes) will be used for all of the MICE magnets.
• The performance of the match coils for the MICE tracker magnet is not understood. The actual vendor magnet design will be determine the final match coil operating currents.
• The peak longitudinal forces occur at 240 MeV/c in the flip mode. These forces occur in the focusing magnets when the coupling coil leads are reversed. The coil lead polarity must be checked before going to high currents.
• Two types of power supplies will be used on MICE. The large supply is 300 A at ±10 V. The small supply is ±50 A at ±5 V.
• Pulse tube coolers will be used on all of the MICE magnets.