MICE

1. n International Muon Ionization Cooling Experiment p m MICE • Why MICE? • 2. Measurement • 3. Prototyping • 4. MICE at RAL • 5. schedule

2. Why MICE? Based on Muon collider ideas and development (Palmer et al, 92->), the Neutrino Factory concept (Geer, 1998) resonated in 1998 with the final demonstration of Atmospheric Neutrino Oscillations by the SuperK Collaboration. International workshops: NUFACT 99 (Lyon, France) NUFACT 00 (Montery, California) NUFACT 01 (Tsukuba, Japan) NUFACT 02 (London, UK) NUFACT 03 (Columbia,NY,USA) NUFACT 04 (Osaka, Japan) NUFACT 05 (italy?)  Neutrino Factory is the ultimate tool for study of Neutrino Oscillations -- unique source of high energy ne --reach/sensitivity better by order(s) of magnitude wrt other techniques (e.g. super-beams) for _ m+ e+ne nm * q13* ** matter effects ** *** leptonic CP violation *** ****ne  nm andnt**** NB : leptonic CP violation is a key ingredient in the leading explanations for the mystery of the baryon-antibaryon asymmetry in our universe

3. Where will this get us… X 5 0.10 130 2.50 50 10 Mezzetto comparison of reach in the oscillations; right to left: present limit from the CHOOZ experiment, expected sensitivity from the MINOS experiment,CNGS (OPERA+ICARUS) 0.75 MW JHF to super Kamiokande with an off-axis narrow-band beam, Superbeam: 4 MW CERN-SPL to a 400 kt water Cerenkov@ Fréjus (J-PARC phase II similar) Neutrino Factory with 40 kton large magnetic detector.

4. 3 sigma sensitivity of various options NUFACT Superbeam only Beta-beam only Betabeam + superbeam Upgrade 400kton-> 1 Mton J-PARC HK 540 kton?

5. Neutrino Factory studies and R&D USA, Europe, Japan have each their scheme. Only one has been costed, US study II: + detector: MINOS * 10 = about 300 M€ or M$ Neutrino Factory CAN be done…..but it is too expensive as is. Aim: ascertain challenges can be met + cut cost in half.

6. Particle physicist: • Q: Can a Neutrino Factory be built? • Accelerator physisicst: • A: YES! (US study II, CERN) • but… it is expensive, • and many ingredients • have never been demonstrated! •  R&D is needed. (est. 5yrs) • to • reduce cost and • ascertain performance • among critical items: • *** COOLING *** Cooling component development programme: MUCOOL collabration (US-Japan-UK)

7. IONIZATION COOLING principle: reality (simplified) this will surely work..! ….maybe… • A delicate technology and integration problem Need to build a realistic prototype and verify that it works (i.e. cools a beam) Difficulties lay in particular in • operating RF cavities in Mag. Field, • interface with SC magnets and LH2 absorbers What performance can one get? Difficulty:affordable prototype of cooling section only cools beam by 10%, while standard emittance measurements barely achieve this precision. Solution: measure the beam particle-by-particle RF Noise!! state-of-the-art particle physics instrumentation will test state-of-the-art accelerator technology.

8. ECFA recommendations (September 2001:) MUTAC ( 14-15 jan 2003)(US) The committee remains convinced that this experiment, which is absolutely required to validate the concept of ionization cooling, and the R&D leading to it should be the highest priority of the muon collaboration. Planning and design for the experiment have advanced dramatically(…) EMCOG: (6 feb 2003) (Europe) (…)EMCOG was impressed by the quality of the experiment, which has been well studied, is well organized and well structured. The issue of ionization cooling is critical and this justifies the important effort that the experiment represents. EMCOG recommends very strongly a timely realization of MICE. MUTAC: Muon Technical Advisory Committee (Helen Edwards, et al) (US) EMCOG: European Muon Coordination and Oversight Group (C. Wyss et al)

9. MICE is part of a international concerted effort of R&D towards a Neutrino Factory. It is one of the four priorities set up by EMCOG European Muon Coordination and Oversight Group -- High intensity proton driver -- High power target -- high rep rate collection system (horns, solenoid) -- Ionization coolng demonstration These will correspond to the workpackages of the ECFA/ESGARD superbeam/neutrino factory feasibility study *  (package for detector R&D will be added!) The contribution of experimenters in MICE is justified and necessary given the difficulty of the measurement. In addition it fulfills the ECFA recommendation to increase education in accelerator physics, and builds a community of people who would be able to understand and operate the real system

10. Superbeam/neutrino Factory design study (sub 2004) Neutrino factory The ultimate tool for neutrino oscillations SPL HIPPI Superbeam EURISOL design study (sub 2004) APEC design study (sub 2005) Very large underground lab Water Cerenkov, Liq.Arg Beta beam EURISOL SPL physics workshop: 25-26 May 2004 at CERN  CERN SPSC Cogne meeting sept. 2004

11. An International Muon Ionization Cooling Experiment (MICE) Summary The aims of the international Muon Ionization Cooling Experiment are: To show that it is possible to design, engineer and build a section of cooling channel capable of giving the desired performance for a Neutrino Factory; To place it in a muon beam and measure its performance in a variety of modes of operation and beam conditions. The MICE collaboration has designed an experiment where a section of an ionisation cooling channel is exposed to a muon beam and reduces its transverse emittance by 10% for muon momenta between 140 and 240 MeV/c. The beam never lies The experiment has been called for, recommended and APPROVED…. … conditional to proper funding and support. Under these same assumptions, ionization cooling of muons will be demonstrated by 2008

12. 10% cooling of 200 MeV/c muons requires ~ 20 MV of RF single particle measurements => measurement precision can be as good as D ( e out/e in ) = 10-3 never done before either…. Coupling Coils 1&2 Spectrometer solenoid 1 Matching coils 1&2 Matching coils 1&2 Spectrometer solenoid 2 Focus coils 1 Focus coils 2 Focus coils 3 m Beam PID TOF 0 Cherenkov TOF 1 RF cavities 1 RF cavities 2 Downstream particle ID: TOF 2 Cherenkov Calorimeter Diffusers 1&2 Liquid Hydrogen absorbers 1,2,3 Incoming muon beam Trackers 1 & 2 measurement of emittance in and out

13. Responsibilities as stated in proposal (Hardware)

14. Quantities to be measured in a cooling experiment cooling effect at nominal input emittance ~10% Acceptance: beam of 5cm and 120 mrad rms equilibrium emittance = 2.5 mm.radian curves for 23 MV, 3 full absorbers, particles on crest

15. Emittance measurement Each spectrometer measures 6 parameters per particle x y t x’ = dx/dz = Px/Pz y’ = dy/dz = Py/Pz t’ = dt/dz =E/Pz Determines, for an ensemble (sample) of N particles, the moments: Averages <x> <y> etc… Second moments: variance(x) sx2 = < x2 - <x>2 > etc… covariance(x) sxy = < x.y - <x><y> > Covariance matrix M = Getting at e.g. sx’t’ is essentially impossible with multiparticle bunch measurements Compare ein with eout Evaluate emittance with:

16. G4MICE simulation of Muon traversing MICE

17. requirements on spectrometer system: • must be sure particles considered are muons throughout • 1.a reject incoming e, p, p • => TOF 2 stations 10 m flight with 70 ps resolution • 1.b reject outgoing e => Cerenkov + Calorimeter • 2. measure 6 particle parameters • i.e. x,y,t, px/pz , py/pz ,E/pz • 3. measure widths and correlations … • resolution in all parameters must be better than 10% of width • at equilibrium emittance (correction less than 1%) • s2meas = s2true+ s2res = s2true [ 1+ (sres/ strue)2 ] (n.b. these are r.m.s.!) • 4. robust against noise from RF cavities => Statistical precision 105 muons  D( e out/ ein )= 10-3 in ~ 1 hour Systematics!!!!

18. tracking in a solenoid: B • Baseline tracker • 5 planes of scintillating fiber tracker • with 3 double layers. • passive detector + fast • good for RF noise Very small fibers needed to reduce MS Little light  VLPC readout (D0 experience)

19. TRANSVERSE MOMENTUM RESOLUTION OK RESULTS Pz resolution degrades at low pt : resolution in E/Pz is much better behaved measurement rms is 4% of beam rms

20. Tracker R&D The prototype Sci-fi: a prototype of 3 out of 5 stations (3 double planes each) Was bulit and tested at D0 test stand Analysis in progress. A ‘typical’ cosmic ray track Fiber feed-throughs

21. MICE tracker back-up option: TPC with GEM readout. 250 microns pads connected in 3 sets of strips 1st Prototype being built difficulties: Long time constant RF photons on the GEMs? RF noise?

22. RF test setup – TPG in LinacIII at CERN detector to RF tanks ~30cm Detector back to RF power supply ~1m L.V. power supply H.V. power supply GEM DETECTOR

23. Noise with RF: no sign of effect on GEMS Fe55 55Fe pulse height: ~300mV Noise: ~40mV! Zoomed signal signal

24. Backgrounds real background reduced by factor L/X0(H2) . L/X0(det) 0.07 0.0026 measured dark currents • Extrapolation to MICE (201 MHz): • scale rates as (area.energy) X 100 • and apply above reduction factor 2 10-4 • 4 104 Hz/cm2 @ 8 MV/m @805 MHz • 0.8 kHz/cm2 per sci-fi • 500 kHz/plane (gate is 20ns) ! within  one order of magnitude ! Dark current backgrounds measured on a 805 MHz cavity in magnetic field! with a 1mm scintillating fiber at d=O(1m)

25. RF cavity (800 MHz) at Fermilab being pushed to its limits (35 MV/m) to study dark current emission in magnetic field. Sees clear enhancement due to B field. Various diagnostics methods photographic paper, scintillating fibers Microscope ------ BCT and solid state counters have demonstrated this and allowed precise measurements Real cavities will be equipped with Be windows Which do not show sign of being pitted contrary to Cu

26. Absorber/Coil Assembly Absorber is interchangeable, can be repaired or changed to solid absorber.

27. LH2 Window R & D (IIT, NIU, ICAR) Various shapes have been studied to --reduce thickness -- increase strength -- Breaking point was measured! Strain gages ~ 20 “points” Shape measurement at FNAL Pressure tests at NIU Photogrammetry ~1000 points

28. Absorber II Absorber body will be built at KEK 2 prototypes have been built Third one according to Safety-compliant design safety review 9-10 dec. 2003

29. RF module MICE is foresen with 8 RF cavities Closed with Be windows (increase gradient / MW RF power) 201 MHz First cavity prototyped Completion in 2004 RF power sources : Will be assembled from equipement refurbished from Berkeley, Los Alamos, CERN, RAL. Needed 8 MW peak power  23 MV acceleration Operation at LN2 foreseen to increase Volts / MW

30. First cavity shells  have been produced Similarly to LiH2 absorber windows, the RF windows will be bell shaped to minimize thickness (800 MHz prototype -

31. INSTALLATION OF MICE at RAL

32. Beam line will include a 5m long 5T solenoid from PSI (CH)

33. H2 absorber Hall has been emptied and preparations to host the experiment begun Large amount of LiH2 from absorbers requires efficient storage Suggested solution: metallic hydride Ventilation duct Radiation shielding wall H2 Buffer Tank (1m3 approx) Vacuum jacket H2 Storage unit

34. m - STEP I: spring 2006 STEP II: summer 2006 STEP III: winter 2007 STEP IV: spring 2007 STEP V: fall 2007 STEP VI: 2008

35. November 2001: Letter of Intent (LOI) submitted to PSI and RAL January 2002 Positive statements from PSI: cannot host experiment, will collaborate (beam solenoid) March 2002: LOI reviewed at RAL June 2002: Review panel encouraged submission of a proposal. January 2003: Proposal submitted to RAL February 2003: EMCOG recommends timely realization of MICE May 2003: International Peer review Panel strongly recommends October 2003: Director(CE) of RAL approves experiment conditional to ‘gateways’… UK funding in the range of >~10 M£ December 9-10 Safety review to clear hydrogen safety design principle … … All seems very well! -- MICE found a home -- Host lab ans UK community enthusiastic Next important steps: Funding has to be secured from the international partners: -- Japan ~OK -- US request to NSF -> decision early 2004 -- request have or will be posted to CH, B, NL, Italy, CEA New collaborators (esp. Accelerator physicists) welcome! NEUTRINO COMMUNITY SHOULD SUPPORT THIS LONG TERM EFFORT!

36. Time Line If all goes well and funding is adequate, Muon Ionization cooling will have been demonstrated and measured precisely by 2008 LHC/J-PARC start-up At that time: MINOS and CNGS will have started and mesured Dm132 more precisely J-Parc-SK will be about to start (Q13 measurement) LHC will be about to give results as well It will be timely (…and not too soon!) to have by then a design for a neutrino factory *), knowing the practical feasibility of ionization cooling *) plans: proposal of a Neutrino factory feasibility study to EU (2004-2007) US Study III (2005 onwards)

38. ECFA recommendations (September 2001:) MUTAC ( 14-15 jan 2003)(US) The committee remains convinced that this experiment, which is absolutely required to validate the concept of ionization cooling, and the R&D leading to it should be the highest priority of the muon collaboration. Planning and design for the experiment have advanced dramatically(…) EMCOG: (6 feb 2003) (Europe) (…)EMCOG was impressed by the quality of the experiment, which has been well studied, is well organized and well structured. The issue of ionization cooling is critical and this justifies the important effort that the experiment represents. EMCOG recommends very strongly a timely realization of MICE. MUTAC: Muon Technical Advisory Committee (Helen Edwards, et al) (US) EMCOG: European Muon Coordination and Oversight Group (C. Wyss et al)

39. High intensity proton driver. Activities on the front end are ongoing in many laboratories in Europe, in particular at CERN, CEA, IN2P3, INFN and GSI. Progressive installation of a high intensity injector and of a linear accelerator up to 120 MeV at CERN (R. Garoby et al) would have immediate rewards in the increase of intensity for the CERN fixed target program and for LHC operation. This (HIPPI) has received funding from EU! • 2.Target studiesproblem at 4 MW!! • . This experimental program is underway with liquid metal jet studies. Goal: explore synergies among the following parties involved: CERN, Lausanne, Megapie at PSI, EURISOL, etc… • Experiment at CERN under consideration by the collaboration. (H. Kirk et al) • 3.Horn studies.Problem at 50 Hz and 4 MW • A first horn prototype has been built and pulsed at low intensity. Mechanical properties measured (S. Gilardoni’s thesis, GVA) • 5 year program to reach high intensity, high rep rate pulsing, and study the radiation resistance of horns. Optimisation of horn shape. IN2P3 Orsay has become leading house for this. Collaborations to be sought with Saclay, PSI (for material research and fatigue under high stress in radiation environment) • Muon Ionization CoolingNever done! • A collaboration towards and International cooling experiment MICE has been established with the muon collaboration in United States and Japanese groups. There is a large interest from European groups in this experiment. Following the submission of a letter of Intent to PSI and RAL, the collaboration has prepared a full proposal at RAL. • Proposal has been strongly encouraged and large UK funding of 10M£ should be available. • PSI offers a solenoid for the muon beam line • CERN, which as already made large initial contributions in the concept of the experiment, • has earmarked some very precious hardware that could be recuperated. (RF! Cryo?) • More collaboration needed from European institutes outside UK.

40. Participating institutes: (142 authors) • Belgium: Louvain La Neuve (Ghislain Gregoire) • Netherlands: NIKHEF amsterdam (Frank Linde) • INFN: Bari (Gabriella Catanesi) Frascati (Michele Castellano) Genova (Pasquale Fabbricatore) • Legnaro (Ugo Gastaldi) Milano (Maurizio Bonesini) Napoli (Giuseppe Osteria) , • Padova (Mauro Mezetto) , Roma(Ludovico Tortora), Trieste (Marco Apollonio) • France DAPNIA, CEA Saclay (Jean-Michel Rey) • Switzerland: Geneva (Alain Blondel), ETH Zürich (André Rubbia), PSI (Claude Petitjean) • UK: Brunel (Paul Keyberd), Edimburg(Akram Khan, Glasgow (Paul Soler), • Rutherford Appleton Laboratory (Rob Edgecock), University of Oxford (Giles Barr), • Imperial College London (Ken Long), Liverpool (John Fry), Sheffield (Chris Booth) • CERN (Helmut Haseroth) • Russia Budker Institute Novosibirsk (Sasha Skrinsky) (+ Dubna, Lebedev under discussions) • Japan KEK (Shigeru Ishimoto), Osaka University(Yoshitaka Kuno) • USA Argonne National Laboratory (Jim Norem) • Brookhaven National Laboratory (Bob Palmer) • Fermi National Accelerator Laboratory (Steve Geer, Alan Bross) • Lawrence Berkeley National Laboratory (Michael Zisman) • University of Iowa (Yasar Onel), Fairfield University (David Winn) • University of California Los Angeles (David Cline) • University of Mississippi (Don Summers) • U.C. Riverside, (Gail Hanson) • University of Chicago – Enrico Fermi Institute(Marco Oreglia) • Northern Illinois University (Mary Anne Cummings) • Illinois Institute of Technology (Danial Kaplan) • Jefferson Lab (Bob Rimmer)

41. International Muon Ionization Cooling Experiment • Organization: • Executive Board • A. Blondel1 (University of Geneva) P. Drumm5 (RAL), R. Edgecock (RAL), V. Palladino • H. Haseroth (CERN), K. Long (ICL, London) I. Ivaniouchenkov2 (RAL) • Y. Kuno (Osaka University) • S. Geer (FNAL), D. Kaplan 3(Illinois Institute of Technology) M. Zisman (Lawrence Berkeley Laboratory) • Y. Torun4 (Illinois Institute of Technology) • 1 spokesperson, 2 project engineer, 3deputy spokesperson, 4secretary, 5Technical coordinator • Technical Board.. Collaboration meetings 3 times a year: US,UK,EU, etc… S.G. phone conf. every 2 weeks Video Conferences every 2 weeks (not easy!) Web site, copies of transparencies, MICE-Notes, common software, speakers bureau, collaboration board (1/institute)

42. COST TABLE and RESPONSIBILITIES warning: assignment of tasks will be revised when cost savings are understood (decision on tracker) rebaselining of the experiment in march 2004. possible cost savings -- use refurbished RF from CERN: - 2500.- k€ -- use TPG or multiplex sci-fi tracker - 3000.- k€ -- use HARP electronics - 500.- k€ net cost if all savings apply: 19.2- M€(Re: LOI 17.8 M$)

43. Time Lines Time lines for the various items of MICE have been explored – procurement delays and installation – the critical items are solenoids and RF cavities. (R&D being pursued on smaller and cheaper 805 MHz RF cavities) This is consistent with the logistics of the beam line upgrade at RAL and of the various shut downs. UK: funding has been prepared since a year US: Proposal has been submitted to NSF Italy: review of funding request on 15 March Belgium and NL: request submitted Switzerland: discussions in progress CERN, PSI: hardware earmarked etc…

44. Time Lines Time lines for the various items of MICE have been explored – procurement delays and installation – the critical items are solenoids and RF cavities. Tracher decision

45. Conclusions There is no doubt that a Neutrino Factory is the ultimate tool to study neutrino oscillations and leptonic CP violation, and a first step towards muon colliders. Can it be done? Paper studies say Yes, but these are only paper studies… involving several new concepts, the newest being ionization cooling. MICE aims at turning this new concept into an apparatus that works, with a community of people able to operate it, maintain it, improve it. The MICE collaboration, supported by the enthusastic UK community, has designed an experiment based on a full cell of US studyII and a set of spectrometers to measure the emittance reduction of 10% with a precision of 10-3. It will also be capable of exploring a number of beam and optics conditions beyond the baseline. The collaboration has organised responsibilities, and determined the costs and time line of the experiment. The crucial safety issues have been addressed and a solution is proposed that should be adequate. The large players have gone -- or are ready to go -- ask for funds. If all goes well ionization cooling will have been demonstrated in 2008. This is very timely and …… not too soon!

49. Further Explorations We have defined a baseline MICE, which will measure the basic cooling properties of the StudyII cooling channel with high precision, for a moderate gradient of ~8 MV/m, with Liquid Hydrogen absorbers. Many variants of the experiment can be tested. 1. other absorbers: Various fillings and thicknesses of LH2 can be envisaged The bolted windows design allows different absorbers to be mounted. 2. other optics and momentum: nominal is 200 MeV/c and b = 42 cm. Exploration of low b (down to a few cm at 140 MeV/c) Exploration of momentum up to 240 MeV/c will be possible by varying the currents. 3. the focus pairs provide a field reversal in the baseline configuration, but they have been designed to operate also in no-flip mode which could have larger acceptance both transversally and in momentum (Fanchetti et al) (We are not sure this can be done because of stray fields…) 4. Higher gradients can be achieved on the cavities, either by running them at liquid nitrogen temperature (the vessel is adequate for this) (gain 1.5-1.7) or by connecting to the 8 MW RF only one of the two 4-cavity units (gain 1.4)