MICE: The International Muon Ionization Cooling Experiment
Ulisse BravarUniversity of Oxford
ICHEP ‘04 1
MICE: The International Muon Ionization Cooling Experiment
Ulisse Bravar University of Oxford
18 August 2004 •Neutrino Factories•Ionization Cooling•The MICE experiment•MICE goals & structure •Present status of MICE•Future developments
MICE: The International Muon Ionization Cooling Experiment
Ulisse BravarUniversity of Oxford
ICHEP ‘04 2
Neutrino Beam Experiments
Neutrinos:• Three flavor states : = e, , • Three mass states : i i = 1, 2, 3
Mixing Matrix: 3 mixing angles • 12 -> solar • 13 -> reactor and beam • 23 -> atmospheric
Oscillation probability in vacuum: P(a->b) = sin2 2 sin2 (1.27 m2 L / E)
13 experiments:• present limit from CHOOZ • expected sensitivity from MINOS• Neutrino Factory with 40 kton large
magnetic detector
0.10 10 2.50 50 130
MICE: The International Muon Ionization Cooling Experiment
Ulisse BravarUniversity of Oxford
ICHEP ‘04 3
Neutrino Factory Layout• Target and collection
– High + and - yield– Sustain high power– Capture as many produced
pions as possible• Muon cooling
– Reduce +/- phase space to capture as many muons as possible in an accelerator
• Muon acceleration– Has to be fast, because
muons are short-lived !
From ECFA/CERN Study, 2004
MICE: The International Muon Ionization Cooling Experiment
Ulisse BravarUniversity of Oxford
ICHEP ‘04 4
Beam Emittance
Emittance:
x = x x’
• Liouville’s theorem use dissipative forces to reduce x
x
x’Large emittance
away from a focus
Large emittanceclose to a focus
Small emittance
B-field:x = constant
Cooling=
reduction of x
x’ = dx/dz = px/pz
z
x
MICE: The International Muon Ionization Cooling Experiment
Ulisse BravarUniversity of Oxford
ICHEP ‘04 5
Ionization Cooling
PRINCIPLE:
REALITY (simplified):
Stochastic cooling is too slow.A new method for and - is needed: ionization cooling
Cooling channel = LINAC + AbsorberAbsorber = cooling from dE/dx + heating from multiple scattering
Select absorber material with minimum multiple scattering for fixed dE/dx lossBest material is liquid hydrogen LH2 !!!
Absorber + RF + B-field
MICE: The International Muon Ionization Cooling Experiment
Ulisse BravarUniversity of Oxford
ICHEP ‘04 6
The MICE ExperimentGOALS:• Design, engineer and build a section of a cooling channel capable of giving
the desired performance for a Neutrino Factory.• Place this apparatus in a ~200 MeV/c muon beam and measure its
performance in a variety of operating modes and beam conditions.
CHALLENGES:• Contain cost. Neutrino Factory cooling channel is ~100 m long and cools the
beam by a factor 10. To be affordable, the MICE cooling channel is only ~6 m long and provides 10% to 15% measurable cooling.
• Measure emittance reduction OUT / IN to 10-3.• Operate high-gradient RF cavities in solenoidal field and with field
terminators.• Safely operate LH2 absorbers with very thin containers.
• Ionization cooling has never been demonstrated in the past. A working ionization cooling channel has never been built or tested !!!
MICE: The International Muon Ionization Cooling Experiment
Ulisse BravarUniversity of Oxford
ICHEP ‘04 7
The MICE CollaborationLouvain
DAPNIA
CEA/Saclay
Bari
Frascati
Genova
Legnaro
Milano
Napoli
Padova
Roma
Trieste
NIKHEF
Novosibirsk
CERN
Geneva
ETH
PSI
KEK
Tsukuba
Osaka
Brunel
Edinburgh
Glasgow
Liverpool
Imperial College
Oxford
CLRC RAL
Sheffield
Argonne
Brookhaven
Fairfield University
University of Chicago
Enrico Fermi Institute
Fermilab
Illinois Institute of Technology
Jefferson Lab
LBL
UCLA
NIU
Iowa
Mississippi
UC Riverside
MICE: The International Muon Ionization Cooling Experiment
Ulisse BravarUniversity of Oxford
ICHEP ‘04 8
MICE Layout
5.5 m
MICE: The International Muon Ionization Cooling Experiment
Ulisse BravarUniversity of Oxford
ICHEP ‘04 9
MICE PerformanceCOMPONENTS:
• 18 superconducting coils + cryocoolers. Solenoidal B-field, BZ ~ 4 T. Contain & focus the muons
in the channel.
• 3 liquid hydrogen LH2 absorbers in
thin Al containers. Provide dE/dx energy loss = cooling.
• 2 RF cavity modules, with a total of eight 201.25 MHz cavities. Field gradient = 8 MV/m. Restore lost energy.
• Upstream and downstream spectrometer. Measure beam emittance to 10-3.
• Particle ID detectors. Reject background events to 10-3.
MICE: The International Muon Ionization Cooling Experiment
Ulisse BravarUniversity of Oxford
ICHEP ‘04 10
MICE at RALSite Proposed for MICE Plant
Proposed route for services
Alternative route for services
Proposed site for controls & control room (presently the cable store and under the ISIS control room).
Proposed new linac cooling plant room
Hall has been emptied and preparation to host the experiment begun
Hole in the ISIS vault
MICE: The International Muon Ionization Cooling Experiment
Ulisse BravarUniversity of Oxford
ICHEP ‘04 11
MICE BeamlineDetailed design now beginning to achieve muon rates of the order of 100 Hz, as needed by MICE
z (m)
em
ittan
ce (
m r
ad)
Present beam almost ideal to demonstrate cooling
z (m)
COOLING IN MICE
Present design beam cools almost as well as ideal case
PSI solenoid
LH2
RF
out
in
MICE: The International Muon Ionization Cooling Experiment
Ulisse BravarUniversity of Oxford
ICHEP ‘04 12
Focus Coil-Absorber Module
Liqu
id h
ydro
gen
cell
35 c
m t
hick
Tw
o A
l win
dow
s on
ea
ch s
ide
of L
H2,
20
0 m
thi
ckne
ss
Superconducting coilsolenoidal B-field
Stored E = 1.3x106 JBpeak in coil = 6.27 T
Inter-coil F = 1.55x106 N
Cryostat
Side view
35 cm
Front view
30 cm
MICE: The International Muon Ionization Cooling Experiment
Ulisse BravarUniversity of Oxford
ICHEP ‘04 13
RF module(CERN, JLAB, LANL, LBL, RAL)
MICE R&DLH2 window
(ICAR, IIT, KEK, NIU, Oxford)
RF Cavity has been cleaned at J-Lab and
started nose
welding and ports annealing
at NASA in July 2004
The challenge:Thin Al windows ~ 120 m
+ safety regulationsFirst vessel has been filled with LH2 at FNAL in spring
2004
MICE: The International Muon Ionization Cooling Experiment
Ulisse BravarUniversity of Oxford
ICHEP ‘04 14
MICE TrackerAlternative option:
TPC with GEM readout (TPG)Baseline option:
Scintillating fiber tracker
5 planes of Sci-FiWith double layer.0.35 X0 per layer
The prototype
MICE: The International Muon Ionization Cooling Experiment
Ulisse BravarUniversity of Oxford
ICHEP ‘04 15
MICE Particle ID• Upstream:
– TOF hodoscopes with 10m path, 70 ps resolution
– Cherenkov / separation at better than
1% at 300 MeV/c • Downstream: 0.5% of s decay in flight:
need electron rejection at 10-3 to avoid bias on emittance reduction measurement– TOF hodoscope– Aerogel Cherenkov
(n=1.02, blind to s)– Calorimeter for MIP vs
E.M. Shower
Ckov Cal
MICE: The International Muon Ionization Cooling Experiment
Ulisse BravarUniversity of Oxford
ICHEP ‘04 16
- STEP I: spring 2006
STEP II: summer 2006
STEP III: winter 2007
STEP IV: spring 2007
STEP V: fall 2007
STEP VI: 2008
MICE Timescale2006
2007
2008
Subject to availability of funds…
……
……
……
……
……
MICE: The International Muon Ionization Cooling Experiment
Ulisse BravarUniversity of Oxford
ICHEP ‘04 17
Summary
• Ionization cooling is an essential ingredient in a neutrino factory
• MICE will demonstrate for the first time its feasibility
• Detailed design and simulation of MICE well under way
• Hardware elements are being built and tested
• Dedicated hall and beamline at RAL in preparation
• MICE should be up and running by 2008