MICE NFrelated people

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MICE ( NF-related people)
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MICE Intl. Muon Cooling Expt

• EU CH JP UK USA collaboration to
• Demonstrate ionisation cooling of a muon beam
• Verify beam dynamics in solenoidal optics
• energy loss and multiple scattering (well
  known?)
• Demonstrate engineering of cooling channel

Ionisation cooling expected but not
demonstrated Engineering, especially with LH2 ,
challenging Will be done in new muon beam at RAL
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A Neutrino Factory (US FS2-A)
HARP Hadron production
MICE Demonstrate ionisation cooling
FFAGs New since FS2
ELMS Theory of dE/dX Multiple Scattering
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Ionisation Cooling must work
Muon loses pt and pl in absorber
RF acceleration replaces pl
Emittance size ? divergence of beam reduced to
fit muon accelerators
Cooling important for NF essential for Muon
Colliders
Acceleration not required to demonstrate
reduction of normalised emittance
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The Guts of MICE
Coupling coil
Focus coils
Cavities
FS2B
Cost of cooling possibility of FFAGs for muon
acceleration ? simpler cooling with LiH
absorbers adopted for FS2-B
Absorber
MICE is 1 lattice section of US-FS2 cooling
channel Full FS2 cooling section was about 100 m
with LH2 absorbers
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FULL MICE (STEP VI)
Cool m
Tracker PID
Flux Shield
Tracker PID
Hot m

• Oxford RAL-ED to supply commission Focus
  Coils
• ? Engineering Integration, Magnets Beam Optics
  coupled
• 20 litres LH2 per absorber ? Safety

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MICE PHASES STEPS
Possible to observe cooling in STEP III
2008
2010?
STEPS V VI have acceleration require RF and
C. Coils
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MICE Activities
Nominal hardware activity is engineering of AFC
modules D.O. team have contributed extensively
to every part of MICE Absorber windows, Cavity
windows, Tracker solenoids, Radiation shutter,
Diffuser, ISIS target, Flux shields, Engineering
reviews Safety....
Also (Witte) to specific (AFC) general MICE
magnetic design
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Design of Focus Coil Modules evolved...

• Cost
• Cryocoolers for coils absorbers
• Safety
• Separate absorber magnet vacuums

Concept ?
1.5 years ago ?
Today ??
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Mechanical Magnetic Analyses

• 3D FEA analysis of focus coils
• 200 tons internal
• 80 tons external

Magnetic quench analysis ( RAL-ED) Does 1 MJ
stored E boil LH2 ? ? WMD?
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Detailed AFC Module Engineering
Warm vessel
Cold mass support
Cold mass adjustment Align coils to mm and mr
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Other Engineering
Curved RF Cavity windows
Thin Be window
Thermal Mechanical FEA
Thin radiation shutter
201 MHz Cavity (LBL)
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Safety

• Safety review, LBNL, Dec. 2003 recommended
• Study effect of catastrophic LH2 spill
• Develop welded seals for absorber windows

Absorber window bayonet thread
Welded assembly
Ongoing MICE Design Safety Audit (W.L.)
Fitness for Purpose Safety of each component
Thermal stress from LH2 spill
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MICE MAGNETICS (ongoing)
B at TOF counters
10 spaced sheets

• Quench analyses for
• entire magnetic channel of 18 inductively
  coupled coils
• quench forces on critical components e.g. lead
  diffuser
• 3-D field maps to MICE software
• including iron disc magnetic shields for PID
  detectors
• Discover shielding may be marginal (gt 1kG)?
  attempt to optimise
• Check new Tracker Solenoid design b functions
  ? Feedback ? LBL

(FemLab FEA calculations by H. Witte)
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Back on Level 6 or MICE Beam Optics

• Studies of
• Expected performance of MICE
• How to analyse single particle experiment
• alignment tolerances for MICE
• how to match through MICE
• Find matches (aka lattice solutions) as design
  of coils evolves
• for several muon momenta
• for several configurations (flip/non-flip)
• for MICE stages III VI
• Many iterations
• Identify problems
• e.g. spaced for radiation shutter ? optimise
• Performance of Step III with solid absorbers
  (first cooling demo. ?)
• ? need to understand emittance growth in drifts

A few examples as existence proof ?
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Expected performance degradation due
to misalignment
Matching effect of space for radiation shield
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• MICE is single particle experiment
• Calc. distribution of amplitudes

Amplitude distribution
Single particle amplitudes
LiH, Li, Be, CH, C
Study cooling in Step 3 ? Possible

• Emittance growth in drift
• Non-linear optics to be understood

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MICE SCHEDULE
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Summary

• We have made are making essential
  contributions to
• mechanical engineering of many aspects MICE
• (Thanks to skills of team in D.O.)
• magnetic design of MICE
• These are highly regarded within MICE
• We are on top of cooling theory (some) beam
  dynamics
• have also made essential contributions to these
  for MICE
• (and we started as particle physicists.... other
  pp groups working on the particle detectors
  software)
• A personal concern MICE will be a long-haul
  (semi) particle physics experiment how best to
  use it to acquire the essential accelerator
  physics skills? Please advise.

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THE END