Goals and Status of MICE The International Muon Ionization Cooling Experiment J.S. Graulich

Plan  Motivations  Muon Cooling  MICE Design and Challenges  MICE’s current status Beam Line Detectors Simulation and Analysis Software  Preparing for the future  Conclusion WIN 11J.S. GraulichSlide 2

WIN 11J.S. GraulichSlide 3 Motivations: Neutrino Physics  Fundamental questions raised by neutrinos Do they conserve the lepton number? Are they their own anti-particle ? Do they have Majorana masses ? Do their oscillations violate CP ? Why masses are so small ?  A strong need for precision measurements Mixing angles, Mass differences, Mass Hierarchy,  CP  Requires a new generation of facilities Among the options: Super beam, Beta beam and Neutrino factory Neutrino factory is not the simplest offers the best potential: performance and flexibility See Boris Kayser’s talk: “Seeking CP violation in neutrino oscillation is now a worldwide goal.”

Motivation: The Neutrino Factory Slide 4 High energy & intensity Very well defined beam content ( , e ) or ( , e ) Start to End Simulation exists IDS ! see A. Cervera 3 essential R&D needed - High power Target - Muon Cooling - FFAGs The neutrino factory is the ultimate tool for precise neutrino studies Sensitivity to  CP CERN Scientific Policy Committee, March 2010

Muon Cooling  Large divergence > < efficient acceleration  Beam Cooling = Emittance reduction  What is emittance ? ≠ divergence In the 2D case (oversimplified) a beam is defined by a set of x i (z) x’ = dx/dz = Px/P WIN 11J.S. GraulichSlide 5 In the absence of dissipative forces,  is conserved !

Ionization Cooling  How to reduce emittance ? -> Frictions  Standard techniques don’t work for muons They need >> 2.2  s  Two steps Energy loss by ionization (dE/dX) Forward re-acceleration by RF cavities WIN 11J.S. GraulichSlide 6 Cooling is achieved only for low Z material ! Mult. Scat. < dE/dx -> Liquid Hydrogen

Cooling Cell  Easy in principle…  In practice, the emittance is so large that Need to contain the beam Not single pass -> iterations  Technical Challenges An extended liquid Hydrogen cryogenic system High gradient RF cavities in strong magnetic field Large number of Superconducting coils strongly coupled to each other  That’s why we need R&D -> MICE WIN 11J.S. GraulichSlide 7

MICE WIN 11J.S. GraulichSlide 8  Muon Ionisation Cooling Experiment Design, build and operate a realistic section of cooling channel Measure its performances (in different modes)

MICE Step By Step Commission beam line & detectors Precisely measure incoming emittance & compare trackers Precisely measure muon cooling Test sustainable cooling Ultimate MICE goal: operate full cooling channel Slide 9 J.S. Graulich 2012 Complete ! (This talk)

WIN 11J.S. GraulichSlide 10 MICE RAL  Rutherford Appleton Laboratory, UK Brand new muon beam line Obtained from ISIS (800 MeV proton Synchrotron)

WIN 11J.S. GraulichSlide 11 MICE Beam Line Design Specifications: - ~ - ~ 1 Spill / 2 seconds - ~ - ~ 3 ms Spill duration muons / Spill - Muon momentum between 140 to 240 MeV/c - p D2 = p D1 /2 (backward muons) D1 D2 Q1-Q3 Q4-Q6Q7-Q9

The Beamline is Operational WIN 11J.S. GraulichSlide 12 Pion Decay Solenoid (during installation) Q7-Q9 Q4-Q6 D2 Downstream Muon Beam Line Mice Target System in ISIS Upstream Pion Beam Line Q1-Q3 D1

The Target is pulsing Stator Position reading Bearing Ti Target Water Cooling MICE Ti Target inside the ISIS beam pipe  Critical active part  Parasitic mode: no perturbation to ISIS Users  80 g acceleration !  Magnetic “gun”  Hz

Slide 14 Instrumentation for Step 1 All detectors for Step 1 are operational TOF0 after the 2 nd triplet TOF1 after the 3 rd triplet TOF2 at the very end (will move) Luminosity Monitors 3 Time of Flight Stations Calorimeter 2 Cherenkovs Downstream Monitor (GVA1) Beam Profile Monitors

Detector Rates WIN 11J.S. GraulichSlide 15 Detector Rates scale linearly with Beam Loss

Lyon, Octobre 2009Slide 16 All TOF installed  Two crossed layers of scintillator slabs, 1” thick  Fast PMTs on both sides  Muon/pion/electron PID  Measure the RF phase when muon arrives  Magnetic shielding is crucial for TOF1/2 TOF1 installed at RAL TOF Scintillator

TOF Resolution WIN 11J.S. GraulichSlide 17

WIN 11J.S. Graulich Particle Identification Very precise Time of Flight measurement between TOF0 and TOF1 Allows separation between Electrons / muons / pions / For all momenta up to 280 Mev/c

WIN 11J.S. Graulich Selecting Backward Muons We want a muon beam ! We tune the second dipole (D2) to select muons going backward (in C.M. frame) w.r.t. to the original pions’ direction P  ≈ P  / 2

Pure muon Beam WIN 11J.S. Graulich20 Selecting backward muons Pions are not transported Electrons are depleted MICE has a muon beam ! ~ 30 muons/spill/ V.ms

Lyon, Octobre 2009Jean-Sébastien GraulichSlide 21 Simulation and Analysis Software: G4MICE  Based on GEANT 4 for the simulation A deliverable by itself  Also used for beam transport optimization In competition with G4Beamline  Reconstruction of events from both simulation and data Calculate elaborated quantity like  In particular: momentum G4BeamLine Transport G4Mice Simulation and Analysis

WIN 11J.S. GraulichSlide 22

Q789 = -30% Phase Space and Momentum Reconstruction: Q789 scan runs m. apollonio Simulation Data

Phase Space and Momentum Reconstruction: Q789 scan runs m. apollonio Q789 = -20% Simulation Data

Phase Space and Momentum Reconstruction: Q789 scan runs m. apollonio Q789 = -10% Simulation Data

Step 1 Program: beam optics  3 momenta 140, 200, 240 MeV/c  3 input emittances 3, 6 10  mrad  A lot of data on tape  Next run in June 2011 WIN 11J.S. Graulich26

Slide 27 Next Step: Spectrometer Construction problems with the superconducting solenoids Tracker Ready, tested with cosmics, meet resolution specs Installation scheduled for 2012

Lyon, Octobre 2009Jean-Sébastien GraulichSlide 28 Absorbers - FC  Each Absorber contains 20 L of Hydrogen  Produced at KEK, Japan  Thin Aluminum widows, all doubled for safety  The module integrates the absorber with the superconduction focus coil in production at Tesla  Integration to Step IV in st absorber complete at Mirapro

Lyon, Octobre 2009Jean-Sébastien GraulichSlide 29 RFCC Module  Each module contains 4 RF cavities and a superconducting coupling coil  Water cooled copper cavities, 201 MHz  Each module compensates for MeV energy loss in the absorbers  High Gradient (8 MV/m) in strong magnetic field (~4 Tesla)  Manufacturing in progress  Expected for 2013

Summary  The Neutrino factory is the best tool for future precise neutrino studies  MICE is exploring muon ionization cooling which is a key R&D toward the NF  MICE has completed its first step at RAL, UK  The muon beam and the detectors have been successfully commissioned  A particle by particle analysis has already been used to measure the beam emittance, using TOFs  The spectrometers and the first absorber will be installed in 2012  MICE could be completed by 2013 WIN 11J.S. GraulichSlide 30

WIN 11J.S. GraulichSlide 31