MICE at STFC-RAL The International Muon Ionization Cooling Experiment -- Design, engineer and build a section of cooling channel capable of giving the desired performance for a Neutrino Factory; -- Place it in a muon beam and measure its performance in various modes of operation and beam conditions, thereby investigating the limits and practicality of cooling.

Neutrino Factory MICE is one of the critical R&D experiments towards neutrino factories and muon colliders MICE MANY CHALLENGES! MUON COOLING  HIGH INTENSITY NEUTRINO FACTORY HIGH LUMINOSITY MUON COLLIDER With the growing importance of neutrino physics + the existence of a light Higgs (125 GeV) physics could be turning this way very fast! Cooling and more generally the initial chain capture, buncher, phase rotation and cooling rely on complex beam dynamics and technology, such as High gradient (~>16 MV/m) RF cavities embedded in strong (>2T) solenoidal magnetic field

Similar to radiation damping in an electron storage ring: muon momentum is reduced in all directions by going through liquid hydrogen absorbers, and restored longitudinally by acceleration in RF cavities. Thus transverse emittance is reduced progressively. Because of a) the production of muons by pion decay and b) the short muon lifetime, ionization cooling is only practical solution to produce high brilliance muon beams COOLING -- Principle is straightforward… Transverse:

Emittance exchange involves ionization varying in space which cancels the dispersion of energies in the beam. This can be used to reduce the energy spread and is of particular interest for  +  -  H (125) since the Higgs is very narrow (~4.2 MeV) COOLING -- Principle is straightforward… Longitudinal:

Similar to radiation damping in an electron storage ring: muon momentum is reduced in all directions by going through liquid hydrogen absorbers, and restored longitudinally by acceleration in RF cavities. Thus transverse emittance is reduced progressively. Because of a) the production of muons by pion decay and b) the short muon lifetime, ionization cooling is only practical solution to produce high brilliance muon beams Emittance exchange involves ionization varying in space which cancels the dispersion of energies in the beam. This can be used to reduce the energy spread and is of particular interest for  +  -  H (125) since the Higgs is very narrow (~5MeV) COOLING -- Principle is straightforward… Transverse: Longitudinal: Practical realization is not! MICE cooling channel (4D cooling) 6D candidate cooling lattices

6 MICE the Muon Ionization Cooling Experiment Particle by particle measurement, then accumulate few 10 5 muons   [ (  in -  out )/  in ] = Measure input particle x,x’,y,y’, t, t’=E/Pz  input emittance  in Measure output particle x,x’,y,y’, t, t’=E/Pz  output emittance  out COOLING CHANNEL

MICE Project Board IV Alain Blondel 7 Progress success scope for MICE Facilities based on muon storage rings have been advocated for several physics applications of great interest with discovery potential A. nuSTORM:  /s storage ring: (<1%) e   e   x-sections and sterile search B. neutrino factory:  /s storage ring precision study of CPviolation, unitarity C. Precision muon collider Higgs factory studies of X(125.5), H/A system (if there) ultra-precise measurements of any new particles in GeV range D. High energy muon collider: the most powerful envisaged machine to search the high energy frontier For B C D the high intensity muons beams are generated and prepared in a powerful magnetic ‘bottle’, from the target solenoid all the way to the last stages of cooling. This magnetic ‘bottle’ consists of continuous magnetic field lines generated by a string of axial coils and solenoids. This is the key to high intensity muon beams MICE is such a magnetic ‘bottle’, from the diffuser to the end of the experiment. Cooling is the aim of the experiment but the lessons learned extend beyond that. (all the front end of the neutrino factory and muon collider) MICE was designed to test the concept in stages with important results at each step

8 STEP VI MICE STEPS Both for funding and science reasons MICE is executed in Steps …. Originally we had 6 Steps We will probably only have 3 steps step I, step IV, step VI COMPLETED, EMR run in Q Q till Q Aim: Q Possible stop-over Q3 2017

9 Incoming muon beam Variable Diffuser Beam PID TOF 0, TOF 1 Cherenkovs Trackers 1 & 2 Liquid Hydrogen absorbers 1,2,3 Downstream particle ID: TOF 2, KL EMR RF cavitiesRF power Spectrometer solenoid 1 Spectrometer solenoid 2 Coupling Coils 1&2 Focus coils MICE Collaboration across the planet

10 Incoming muon beam Variable Diffuser Beam PID TOF 0, TOF 1 Cherenkovs Trackers 1 & 2 Liquid Hydrogen absorbers 1,2,3 Downstream particle ID: TOF 2, KL EMR RF cavitiesRF power Spectrometer solenoid 1 Spectrometer solenoid 2 Coupling Coils 1&2 Focus coils MICE Collaboration across the planet MICE is now completely engineered !

Completed and published! Main results: -- It all works! (target, magnets, PPS, DAQ, det..) -- TOF resolution s: 50 ps and 1cm -- ~100 muons per second Beam commissionning M.Bogomilov et al. [MICE Collaboration], The MICE Muon Beam on ISIS and the beam-line instrumentation of the Muon Ionization Cooling Experiment, JINST 7, P05009 (2012) [arXiv: [physics.acc-ph]].

Paper in editorial process Main results: can generate emittance vs momentum matrix can reconstruct momentum with TOF can measure emittance using space points Data MC y (mm) vs x (mm) x (mrad) vs x (mm)y (mrad) vs y (mm) -- first measts of emittance particle by particle with the TOFs Beam commissionning

Paper in editorial process Main results: -- beam composition can be measured using TOF + KL+CKOV -- intensive use of pion + muon beam tunes e   muon tune P D2 = 0.5 P D1 pion tune P D2 = P D1 1. Template of KL pulse height in pion beam   beam composition e   99%   1% 

MICE Project Board IV Alain Blondel 14 Step IV 1. The MICE step IV program will provide a number of important physics and methodological results: -- Liquid hydrogen absorber realisation and safe routine operation -- engineering test of beamline made of several magnetically connected components -- understanding of propagation of (imperfect) beam through the magnetic bottle -- complete particle detector system; calibrations of emittance measurement to  measurement of 6D emittance change (observation of normalized emittance cooling) -- validation of simulation codes -- limited possibility to test the longitudinal cooling with the wedge absorbers -- correlated precision measurements of multiple scattering and energy loss straggling. These measurements will constitute a textbook contribution to experimental particle physics, and will be essential for reliable simulation of the performance of neutrino factory and muon collider.

No absorber Alignment Optics studies Solid absorber(s) LiH Plastic C, Al, Cu LiH Wedge absorber Emittance exchange Liq H 2 absorber (full/empty) Multiple scattering Energy loss  Cooling STEP IV EXPERIMENTS ( ) NB timing of Liq H 2 will depend on timing w.r.t. 6 month ISIS shut-down Aug’14 to Feb’15

16 Make this a photograph by the end of 2013! LH2 system diffuser FOCUS COIL EMR Tracker 2 STEP IV Tracker 1 Spectrometer Solenoid 2 Spectrometer Solenoid 1

MICE Project Board IV Alain Blondel The MUCOOL program at Fermilab RF in magnetic field -- will provide demonstration of the combined magnet and RF hardware that are required for a realistic cooling channel. -- can operate up to 21MV/m -- The U.S. effort presently has a major emphasis on preparing a prototype coupling coil magnet which can be tested with a 201 MHz RF cavity in the MuCool Test Area at Fermilab. -- Upon successful completion of that test, it is anticipated that production hardware can be completed for the MICE beamline. (modified if necessary)

MICE Project Board IV Alain Blondel 18 Step V -- More difficult magnetic situation with one large ‘coupling’ coil -- operation in magnetic field of 4-cavity RF module (normally up to 8MV/m, on special arrangement up to 12 or 16) -- verification of understanding of energy loss and RF acceleration for particles up to large amplitudes and over all phases -- First measurement of usable ionization cooling

MICE Project Board IV Alain Blondel 19 STEP VI -- operation of channel with all magnetic couplings in place. -- full cooling cell allowing all optics configurations: flip, non-flip etc… -- exact replenishment of energy possible -- significant and measurable longitudinal heating -- precise measurement of equilibrium emittance of various configurations -- detailed and precise verification of simulation codes The relative risks (and associated expenses) of step VI wrt Step V have been considered minor wrt to the extra time needed (18 months delay to step VI) and we have agreed (with MPB support) that the baseline option is to skip step V

20 STEP VI Aim: 2018 STEP VI Coupling coil (Harbin China) 20 RF cavities (Berkeley) absorber windows (Mississippi) Liq H2 absorber (KEK) AFC Magnet (RAL/Oxford) RF Amplifier (Daresbury) RF Couplers (Berkeley) Berylium Windows (Berkeley) MICE construction: world-wide team effort! Aim: MICE step VI in 2018

MICE Project Board IV Alain Blondel 21 It will have generated experience and know-how, bridging sometimes painfully a significant gap between the neutrino factory and muon collider dreams … and reality. This « acid test » will set future developments on firmer ground MICE legacy MICE will have achieved the first demonstration of ionization cooling and tested essential concepts for production of intense muon beams Once step VI is complete a powerful Cooling Test Facility is in place with -- a quality muon beam -- 8MW of 200 MHz RF power -- 23MV of acceleration -- infrastructure for 70 litres of liquid Hydrogen absorbers -- instrumentation for precision 6D emittance measurements -- a number of available magnets and associated infrastructure -- and… a number of people who have made (most of) the mistakes already a formidable asset that could be used for e.g. a 6D cooling experiment

MICE Project Board IV Alain Blondel 22 Concluding notes on schedule (as introduction to afternoon discussions) 1. There is great progress all over MICE (LH2, DAQ, FC, publications) 2. We have had progress+setback in the schedule with the Spectrometer solenoid – SS1 has reached full field -- but is not operational yet! 3. MICE (UK+US) have produced a resource loaded schedule to step VI. This is big progress! We understand schedule slippage. 4. This places Step VI at the limit of timeliness in 2018 Still step VI and its experimental richness and thourough testing abilities is the goal of the experiment. We could consider having a stop-over at stepV – but only if we absolutely have to – now is *not* the moment to decide. 5. There are a few ideas on how to improve the schedule within the envelope. 6. There are many risks to the schedule most of which related to the scarce manpower and resources. Any glitch leads to delays. 7. The most efficient solution remains application of appropriate and well targeted influx of manpower: highly beneficial and we believe economical in the long run. 8. The MICE team remains proudly dedicated to achieving the first demonstration of ionization cooling.