MICE at STFC-RAL The International M uon I onization C ooling E xperiment

1. 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.

2. MICE Neutrino Factory MICEis one of the critical R&D experiments towards neutrino factories and muon colliders With the growing importance of neutrino physics + the existence of a light Higgs (125 GeV) physicscouldbeturningthiswayveryfast! Cooling and more generally the initial chain capture, buncher, phase rotation and cooling rely on complexbeamdynamics and technology, such as High gradient (~>16 MV/m) RF cavitiesembedded in strong (>2T) solenoidalmagneticfield MANY CHALLENGES! MUON COOLING  HIGH INTENSITY NEUTRINO FACTORY HIGH LUMINOSITY MUON COLLIDER

3. COOLING -- Principleisstraightforward… Transverse: Similar to radiation damping in an electronstorage ring: muon momentumisreduced in all directions by goingthroughliquidhydrogenabsorbers, and restoredlongitudinally by acceleration in RF cavities. Thustransverse emittance isreducedprogressively. Because of a) the production of muons by pion decay and b) the short muon lifetime, ionizationcoolingisonlypractical solution to producehighbrilliance muon beams

4. COOLING -- Principleisstraightforward… Longitudinal: Emittance exchange involvesionization varying in spacewhich cancels the dispersion of energies in the beam. This canbeused to reduce the energyspreadand is of particularinterest for + -  H (125) sincethe Higgsisverynarrow(~4.2 MeV)

5. COOLING -- Principleisstraightforward… Longitudinal: Transverse: Similar to radiation damping in an electronstorage ring: muon momentumisreduced in all directions by goingthroughliquidhydrogenabsorbers, and restoredlongitudinally by acceleration in RF cavities. Thus transverse emittance isreducedprogressively. Because of a) the production of muons by pion decay and b) the short muon lifetime, ionizationcoolingisonlypractical solution to producehighbrilliance muon beams Emittance exchange involvesionization varying in spacewhich cancels the dispersion of energies in the beam. This canbeused to reduce the energy spread and is of particularinterest for + -  H (125) since the Higgsisverynarrow (~5MeV) Practicalrealizationis not! MICE coolingchannel (4D cooling) 6D candidate coolinglattices

6. MICE the Muon IonizationCoolingExperiment 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 Particleby particlemeasurement, thenaccumulate few 105 muons  [ (in- out)/in ]= 10-3

7. Progress success scope for MICE Facilitiesbased on muon storage rings have been advocated for severalphysics applications of greatinterestwithdiscoverypotential A. nuSTORM: 1011/sstorage ring: (<1%) e e x-sections and sterilesearch B.neutrino factory:1014/sstorage ring precisionstudy of CPviolation, unitarity C.Precision muon colliderHiggsfactorystudies of X(125.5), H/A system (if there) ultra-precisemeasurements of any new particles in 50-1000 GeV range D.High energy muon collider: the mostpowerfulenvisaged machine to search the highenergyfrontier For B C D the highintensity muons beams are generated and prepared in a powerfulmagnetic ‘bottle’, from the targetsolenoid all the way to the last stages of cooling. This magnetic ‘bottle’ consists of continuousmagneticfieldlines generated by a string of axial coils and solenoids. This is the key to highintensity muon beams MICE issuch a magnetic ‘bottle’,from the diffuser to the end of the experiment. Coolingis the aim of the experiment but the lessonslearnedextendbeyondthat. (all the front end of the neutrino factory and muon collider) MICE wasdesigned to test the concept in stages with important resultsateachstep

8. MICE STEPS COMPLETED, EMR run in Q2 2013 Both for funding and science reasons MICE isexecuted in Steps …. Originallywehad 6 Steps Wewillprobablyonly have 3 steps step I, step IV, step VI Q2 2014 till Q4 2015 Possible stop-over Q3 2017 STEP VI Aim: Q3 2018

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

10. MICE Collaboration across the planet Coupling Coils 1&2 Focus coils Spectrometer solenoid 2 Spectrometer solenoid 1 MICE isnowcompletelyengineered ! RF cavities RF power Beam PID TOF 0, TOF 1 Cherenkovs Downstream particle ID: TOF 2, KL EMR VariableDiffuser Liquid Hydrogen absorbers 1,2,3 Incoming muon beam Trackers 1 & 2

11. Completed and published! Main results: -- It all works! (target, magnets, PPS, DAQ, det..) -- TOF resolution s: 50 ps and 1cm -- ~100 muons per second Beamcommissionning 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:1203.4089 [physics.acc-ph]].

12. Paper in editorialprocess Main results: cangenerateemittance vs momentummatrix canreconstructmomentumwith TOF canmeasureemittanceusingspace points Beamcommissionning y (mm) vs x (mm) x (mrad) vs x (mm) y (mrad) vs y (mm) Data -- first measts of emittanceparticle by particlewiththe TOFs MC

13. Paper in editorialprocess Main results: -- beam composition canbemeasuredusing TOF + KL+CKOV -- intensive use of pion + muon beam tunes » 99% m » 1% p beam composition pion tune PD2 = PD1 muon tune PD2 = 0.5 PD1   e  e 1. Template of KL pulse height in pion beam  

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  10-3 -- 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.

15. STEP IV EXPERIMENTS (2014-2015) NB timing of Liq H2willdepend on timing w.r.t. 6 month ISIS shut-down Aug’14 to Feb’15 No absorber Alignment Opticsstudies Liq H2 absorber (full/empty) Multiple scattering Energyloss  Cooling Solid absorber(s) LiH Plastic C, Al, Cu LiHWedge absorber Emittance exchange

16. STEP IV SpectrometerSolenoid 1 FOCUS COIL SpectrometerSolenoid 2 diffuser Tracker 2 Tracker 1 EMR LH2 system Makethis a photograph by the end of 2013!

17. 2. 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)

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

19. STEP VI -- operation of channelwith all magneticcouplings in place. -- full coolingcellallowing all optics configurations: flip, non-flip etc… -- exact replenishment of energy possible -- significant and measurable longitudinal heating -- precisemeasurement of equilibriumemittance of variousconfigurations -- detailed and preciseverification of simulation codes The relative risks (and associatedexpenses) of step VI wrtStep V have been consideredminorwrt to the extra time needed (18 monthsdelay to step VI) and we have agreed (with MPB support) thatthe baseline option is to skip step V

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

21. MICE legacy MICE will have achieved the first demonstration of ionizationcooling and tested essential concepts for production of intense muon beams It will have generatedexperience and know-how, bridgingsometimespainfully a significant gap between the neutrino factory and muon colliderdreams … and reality. This « acid test » willset future developments on firmerground Once step VI iscomplete a powerfulCooling Test Facilityis in place with -- a quality muon beam -- 8MW of 200 MHz RF power -- 23MV of acceleration -- infrastructure for 70 litres of liquidHydrogenabsorbers -- instrumentation for precision 6D emittancemeasurements -- a number of availablemagnets and associated infrastructure -- and… a number of people who have made (most of) the mistakesalready a formidable assetthatcouldbeused for e.g. a 6D coolingexperiment

22. Concluding notes on schedule (as introduction to afternoon discussions) 1. There isgreatprogress all over MICE (LH2, DAQ, FC, publications) 2. We have hadprogress+setbackin the schedulewith the Spectrometersolenoid –SS1 has reached full field-- but is not operationalyet! 3. MICE (UK+US) have produced a resourceloadedschedule to step VI. This isbigprogress! Weunderstandscheduleslippage. 4. This places Step VI at the limit of timeliness in 2018 Stillstep VI and itsexperimentalrichness and thouroughtestingabilitiesis the goal of the experiment. Wecouldconsiderhaving a stop-over atstepV – but only if weabsolutely have to – nowis *not* the moment to decide. 5. There are a few ideas on how to improve the schedulewithin the envelope. 6. There are manyrisks to the schedulemost of whichrelated to the scarcemanpowerand resources. Anyglitchleads to delays. 7. The most efficient solution remainsapplication 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.