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MICE Superconducting Solenoids: Status and
UpdateRAL:T W BradshawM CourtholdJ RochfordM HillsD BaynhamOxford:J CobbW LauS Yang
2010-06-08 MICE Superconducting Solenoids TWB.pptx
Berkeley:M GreenS VirostekM ZismanHarbin:H Pan
X K Liu
L Wang
X L Guo
H Wu
A B Chen
Introduction
• Brief overview of the magnet system
• Status of the coils
Coil # Sponsor
Decay Solenoid 1 PSI (Switzerland) UK integration installation and commissioning of helium plant
Absorber and Focus Coil
3 UK – Oxford University and Rutherford Appleton Laboratory – built in UK
Spectrometer Solenoids
2 US LBNL – built in US
Coupling coils (flip coils)
2 US LBNL – built in China Harbin Institute of Cryogenics and Super Conductivity Technology
Upstream on Beam Line (not part of cooling channel)
Decay Solenoid
Component of the beam line so not part of the MICE lattice
Installed in wall of MICE hall
Unusual in that is cooled with supercritical helium at 4.5K
Field 5T at 870A 1.1MJ
• Area 1.8x3.2mm2
• Cu:Sc 3.5• Icritical 1000 A• Bcrit (from model)
5.9T• So Jcrit of
superconductor 781A/mm2 @ 5.9T and ~4.2K
Solenoid in hall at PSI This was used on a muon channel at PSI and was operated from December 1974 until 2004
Decay Solenoid– 5T Superconducting Solenoid– 115mm bore, 5000mm length, constructed from 10 spools– Designed and built at the Paul Scherrer Institut (PSI) in the
1970s– Cooled by supercritical helium gas to approx. 4.8K– Critical current at 4.8K = 1000A, require 870A for 5T– Requires approx. 23W of cooling power
Decay Solenoid
– Transfer Line comprises 4 vacuum jacketed process lines (4K feed and return + 70K feed and return)
– Many metres of ancillary pipework between cold box, decay solenoid and the gas panels
– Buffer Tank stores the make-up gas required as liquid is formed in the magnet
– Magnet Current provided by 4 large cables between the power supply on the north mezzanine and the magnet turret
Decay Solenoid
• Part of the solenoid radioactive when supplied from PSI
• Replaced “hot” outer nose
• Work on plumbing, power supplies, quench detection ....
• Refrigerator supplied from Linde
• System worked well until we had the refrigerator serviced – leaks, gas purity etc....
......but now back in operation
MICE Lattice
Spectrometer
Spectrometer
Absorber Focus Coil
Absorber Focus Coil
Absorber Focus Coil
Coupling Coil
Coupling Coil
Note – all magnets in lattice use closed cycle coolers for refrigeration
Spectrometer Solenoid
This is the most complicated of the MICE coils
Comprises
1 x centre coil
2 x end coils
2 x matching coils
Spectrometer Solenoid
Magnet has been run at Wang NMR with training as follows 165, 219, 238, 253, 257 A (required current is 275A)
M2 coil open circuit between feed-through on the internal cryostat and the coil.
Magnet is now being disassembled and review board convened to assess the problems
The other spectrometer solenoid (#1!) is awaiting final assembly
This will cause a delay while the problems are being understood
Absorber and Focus CoilThe Absorber and Focus Coil Solenoid consists of two coils on a bobbin
Has to accommodate the hydrogen absorber and safety windows
Closed cycle coolers used on both the magnet system and the hydrogen condensing system
Absorber and Focus Coil
Status
• Completed reviews prior to manufacture
• Thermal model
• Mechanical issues around bobbin material and strength
• Quench protection etc....
Just entering the manufacturing phase with the first coil to be wound in the next few weeks.
First delivery Jan 2011
Second delivery April/May 2011
Third ??? (required 2013)
Coupling Coils
In the process of manufacture by Harbin Institute of Cryogenics and Super Conductivity Technology under contract from Lawrence Berkeley
These will be integrated with 201MHz RF cavities to form the RFCC – RF coupling coil modules.
Length 285mmInner rad750mmLayers 96Inductance 593 HCurrent 210/198A(flip/non flip)
Status:
Design completeIn manufacture
Because of large stray field position and orientation of HTS leads important – need to keep field // to the flat face of the conductor
Summary
The components of the MICE lattice and beam line are in various stages of manufacture and production
MICE – unusual for a particle physics experiment in that all the magnets are cooled by cryocoolers
Decay solenoid – in position and operational
Spectrometer solenoids – due early 2011 – on critical path
Absorber and focus coils – first one Jan 2011 (required Q3 for Step IV)
Coupling coils – required 2012 for Step V (with one rf module)
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