MICE : the Muon Ionization Cooling Experiment

MICE :the Muon Ionization Cooling Experiment - Overview and Status - M. Yoshida (Osaka Univ.) for the MICE Collaboration 2004/7/31 @ Osaka

Contents • Motivation & goals • MICE introduction • Cooling channel R&D • Particle detector R&D • Schedule & Summary

MICE collaboration International collaboration of 37 institute Europe Louvain la Neuve, Saclay, Bari, LNF Frascati, Genova, Legnaro, Milano, Napoli, Padova, Roma III, Trieste, NIKHEF, Novosibirsk, CERN, Genève, ETH Zurich, PSI, Brunel, Edinburgh, Glasgow, Imperial College, Liverpool, Oxford, RAL, Sheffield Japan KEK, Osaka University United States of America ANL, BNL, FNAL, IIT, Chicago Enrico Fermi Inst., LBNL, UCLA, NIU, Mississippi, Riverside

Neutrino Factory concept Muon Cooling Section: To reduce m+/m- phase space to capture as many muons as possible in an accelerator NF concept in Europe

Muon ionization cooling Principle Practice reduce pt and pl heating increase pl • So far, ionization cooling has not been demonstrated. • MICE • check ability to construct cooling channel • investigate the limit and practicality of the cooling • Advantage: • fast in principle (muon life ~ 2ms) • available for both of m+ and m-

MICE history • Instigation NuFact’01 • Letter of Intent submitted to RAL in 2002 • Proposal submitted to RAL on Jan. 10, 2003 • Approval “strongly recommended” by the International Review Panel on May 20, 2003 • Scientific approval from CCLRC chief executive on Oct. 24, 2003 • 1st UK Project Review (Gateway) • Funding Negotiations – in progress in US, EU& JP • 2nd UK Project Review end 2004!

MICE goals (1) • Build a section of cooling channel long enough toprovide measurable cooling (10% reduction oftransverse emittance) • Liquid hydrogen absorber for large dE/dx • High gradient RF cavity for fast cooling ~10% nominal input emittance Curves for 23 MV, 3 full absorbers

MICE goals (2) • Achieve 1% accuracy in the measurement of 10% emittance reduction • Measure absolute emittance with 0.1% precision by tracking single particle before and after cooling channel • Particle ID to reject background pions and electrons • Need careful integration of particle detectors to the cooling channel • Low material to avoid scattering in the detectors • Robust operation in the magnetic field and background from RF

MICE apparatus: Beam & HALL – layout and progress this year • MICE Muon Beam Line: • Shielding to be re-installed • Prepare beam line for installation in next long ISIS shutdown – early (?) 2006

MICE setup

MICE cooling channel • Absorber with large X0 to avoid heating • SC solenoid focusing for small bt • High gradient reacceleration • 10% reduction of muon emittance for 200 MeV muons requires ~20MV RF  integrate these elements in the most compact and economic way • 3 Liquid Hydrogen absorbers • 8 cavities 201MHz RFs, 8MV/m • 5T SC solenoids

Absorber R&D (MUCOOL) • Convection-type absorber cooled by liquid He flow was tested in MTA/FNAL KEK absorber II KEK test cryostat sitting in MTA/FNAL  See S.Ishimoto’s talk

Cooling channel R&D MUCOOL 201 MHz RF module (Berkeley, Los Alamos, JLAB, CERN, RAL) LH2 window (IIT, NIU, ICAR) The challenge: Thin windows + safetyregulations First cavity has been assembled Be window to minimize thickness

Beam diagnostic: components • Particle identification • Upstream:  –  separation • Time-of-flight measurement • Cherenkov • Downstream: –e separation • Cherenkov • Electromagnetic calorimeter • Spectrometers: • Position, momentum, emittance measurement

Cherenkov 2 MUCAL Beam PId scintillators Cherenkov I Diffuser2 TOF1 TOF0 Proton Absorber TOF2 Diagnostic: setup ISIS proton beam spectrometer

Upstream PID • Cherenkov • Tasks: / separation • TOF hodoscopes • Resolution: 70ps resolution • Tasks: • TOF0 – TOF1: / separation • TOFs: measurement of muon phase w.r.t. RF • Trigger and trigger time  p/m separation at better than 1% at 300 MeV/c

Downstream PID • Cherenkov • Aerogel Cherenkov (n=1.02, blind to ms) • Challenge: Operation in fringe field of detector solenoid • E.M. Calorimeter • 0.3mm lead + 1mm scintillating fiber • TOF hodoscope • electron rejection at 10-3 to avoid bias on emittance reduction measurement Aerogel

Spectrometer Requirement • Absolute errors in emittance measurement should be <0.1% • Robustness against harsh environment • X-ray BG from RF cavities • Intense magnetic fields • Solenoid: • 4T magnetic field • 40cm bore

MICE tracker • Alternative option: • TPC with GEM readout (TPG) • Light gas (0.15% X0) • Many points per track •  High precision tracking possible • Need to avoid RF noise on GEM • Baseline option: • Scintillating fiber tracker • 5 planes x 3-fold doublet of 350mmfiber (0.35% X0) • VLPC readout; high QE~80% • No active electronics/HV close to the spectrometer • Safe for LH • Robust in RF BG

SciFi tracker prototype at D0/FNAL test stand 4m long waveguide The prototype with 3 stations was constructed at the D0 test stand in Oct. 2003 in collaboration with JP, UK, and US VLPC cryostat Prototype sitting at D0 test stand

Tracker prototype performance A typical cosmic ray event Light yield ~10p.e. at most probable  e>99% Point resolution ~440 mm • Planning test beam at KEK: • Additional station production – finalise fabrication techniques • Tracking in SC solenoid - verify pattern recognition and momentum measurement in magnetic field

TPG R&D • Test of TPG head using HARP TPC field cage • Operation with cosmic-rays & with test beam is on-going

m - STEP I STEP II STEP III STEP IV STEP V STEP VI MICE installation phases 2006 …………… 2007 …………… 2008

Summary • Detailed & Careful Design of cooling channel has been done • Progress on absorber R&D & RF cavity • Tracker R&D • Baseline option : SciFi • Prototype tests with cosmics was done • Preparing KEK beam test in 2005 with solenoid field • Detailed design of PID system has been done • Start preparatory work at RAL

MICE : the Muon Ionization Cooling Experiment