1. MICE: The International Muon Ionization Cooling Experiment Ulisse Bravar University 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

2. MICE: The International Muon Ionization Cooling Experiment Ulisse Bravar University 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 ) = sin 2 2  sin 2 (1.27  m 2 L / E)  13 experiments: present limit from CHOOZ expected sensitivity from MINOS Neutrino Factory with 40 kton large magnetic detector 0.1 0 1010 2.5 0 5050 13 0

3. MICE: The International Muon Ionization Cooling Experiment Ulisse Bravar University 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

4. MICE: The International Muon Ionization Cooling Experiment Ulisse Bravar University 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 emittance close to a focus Small emittance B-field:  x = constant Cooling = reduction of  x x’ = dx/dz = p x /p z z x

5. MICE: The International Muon Ionization Cooling Experiment Ulisse Bravar University 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 + Absorber Absorber = cooling from dE/dx + heating from multiple scattering Select absorber material with minimum multiple scattering for fixed dE/dx loss Best material is liquid hydrogen LH 2 !!! Absorber + RF + B-field

6. MICE: The International Muon Ionization Cooling Experiment Ulisse Bravar University of Oxford ICHEP ‘04 6 The MICE Experiment GOALS: 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 LH 2 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 !!!

7. MICE: The International Muon Ionization Cooling Experiment Ulisse Bravar University of Oxford ICHEP ‘04 7 The MICE Collaboration Louvain 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

8. MICE: The International Muon Ionization Cooling Experiment Ulisse Bravar University of Oxford ICHEP ‘04 8 MICE Layout 5.5 m

9. MICE: The International Muon Ionization Cooling Experiment Ulisse Bravar University of Oxford ICHEP ‘04 9 MICE Performance COMPONENTS: 18 superconducting coils + cryocoolers. Solenoidal B-field, B Z ~ 4 T. Contain & focus the muons in the channel. 3 liquid hydrogen LH 2 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.

10. MICE: The International Muon Ionization Cooling Experiment Ulisse Bravar University of Oxford ICHEP ‘04 10 MICE at RAL Hall has been emptied and preparation to host the experiment begun Hole in the ISIS vault

11. MICE: The International Muon Ionization Cooling Experiment Ulisse Bravar University of Oxford ICHEP ‘04 11 MICE Beamline Detailed design now beginning to achieve muon rates of the order of 100 Hz, as needed by MICE z (m) emittance (  m rad) Present beam almost ideal to demonstrate cooling z (m) COOLING IN MICE Present design beam cools almost as well as ideal case PSI solenoid LH 2 RF  out  in

12. MICE: The International Muon Ionization Cooling Experiment Ulisse Bravar University of Oxford ICHEP ‘04 12 Focus Coil-Absorber Module Liquid hydrogen cell 35 cm thick Two Al windows on each side of LH 2, 200  m thickness Superconducting coil solenoidal B-field Stored E = 1.3x10 6 J B peak in coil = 6.27 T Inter-coil F = 1.55x10 6 N Cryostat Side view 35 cm Front view 30 cm

13. MICE: The International Muon Ionization Cooling Experiment Ulisse Bravar University of Oxford ICHEP ‘04 13 RF module (CERN, JLAB, LANL, LBL, RAL) MICE R&D LH 2 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 regulations First vessel has been filled with LH 2 at FNAL in spring 2004

14. MICE: The International Muon Ionization Cooling Experiment Ulisse Bravar University of Oxford ICHEP ‘04 14 MICE Tracker Alternative option: TPC with GEM readout (TPG) Baseline option: Scintillating fiber tracker 5 planes of Sci-Fi With double layer. 0.35 X 0 per layer The prototype

15. MICE: The International Muon Ionization Cooling Experiment Ulisse Bravar University 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

16. MICE: The International Muon Ionization Cooling Experiment Ulisse Bravar University 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 Timescale 2006 2007 2008 Subject to availability of funds… ……………

17. MICE: The International Muon Ionization Cooling Experiment Ulisse Bravar University 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