MICE

1. n m p MICE The International Muon Ionization Cooling Experiment

2. 1998: neutrino disappearance is established by SuperKamiokaNDE experiment 1998: first design ideas for muon collider and Neutrino Factory Everything was innovative! Perhaps the most esoteric part was Muon Ionization Cooling. How can one believe this will work? Optics is “different” and poorly understood Never been built No experience in such a thing: How much would it cost? What could go wrong? What is the performance of a real system? Bob Palmer NUFACT 1999

3. Neutrino Factory has gone a way…. 1998

4. Intense K physics Intense Low-E muons Neutrino Factory Higgs(es) Factory(ies) Energy Frontier -> 5 TeV circa 1997-1999 US, Europe, Japan Possible layout of a muon complex on the CERN site.

5. ISS Baseline to scale… still fits within e.g. CERN, FNAL

6. Major challenges tackled by R&D expts High-power target . 4MW . good transmission MERIT experiment (CERN) Fast muon cooling MICE experiment (RAL) } Fast, large aperture accelerator (FFAG) EMMA (Daresbury)

7. IONIZATION COOLING reality (simplified) principle: ….maybe… this will surely work..! Cooling is necessary for Neutrino Factory and crucial for Muon Collider. Delicate technology and integration problem Need to build a realistic prototype and verify that it works (i.e. cools a beam) Can it be built? Operate reliably? 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 state-of-the-art particle physics instrumentation will test state-of-the-art accelerator technology.

8. 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 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 Cherenkovs TOF 1 RF cavities 1 RF cavities 2 Downstream TOF 2 particle ID: KL and EMR Calorimeter VariableDiffuser Liquid Hydrogen absorbers 1,2,3 Incoming muon beam Trackers 1 & 2 measurement of emittance in and out

9. ISIS MICE Hall R5.2 9

10. THE MICE COLLABORATION -130 collaborators- • University of Sofia, Bulgaria • The Harbin Institute for Super Conducting Technologies PR China • INFN Milano, INFN Napoli,INFN Pavia, INFN Roma III,INFN Trieste,Italy • KEK, Kyoto University, Osaka University, Japan • NIKHEF, The Netherlands • CERN • Geneva University, Paul Scherrer InstitutSwitzerland • Brunel,Cockcroft/Lancaster, Glasgow, Liverpool, ICL London, Oxford, Darsbury, RAL, Sheffield, Warwick UK • Argonne National Laboratory, Brookhaven National Laboratory, University of ChicagoEnrico Fermi Institute, Fermilab, Illinois Institute of Technology, • Jefferson Lab, Lawrence Berkeley National Laboratory, UCLA, Northern Illinois University, University of Iowa, University of Mississippi, UC Riverside, Muons Inc.USA new: Y. K. Kim and coll.

11. MICE Collaboration across the planet Coupling Coils 1&2 Focus coils Spectrometer solenoid 2 Spectrometer solenoid 1 m 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

13. Status of MICE Steps

14. m STEP I data taking Apr09|Jun10

15. STEP III/III.1 Q3-Q4 2011 Apr09|Jun10

16. MICE beam line hardware is complete and MICE hall ready for next steps!

17. Recent news Many achievements during the last 6 months: -- completed beam line and -- running routinely with excellent collaboration with ISIS. -- completed most of detector systems (EMR remains) -- observed muon beam routinely -- online reconstruction and first measurement of emittance -- intensity of beam getting close to required for steps I-IV -- published first paper using MICE beam (TOF paper) -- Published tracker paper -- preparing Beamline paper -- welcomed new collaborators -- devised new absorbers -- construction of RF cavities -- BUT…. difficulties with spectrometer solenoid magnets   schedule slip. MUON BEAM!

18. STEP II Q2 2011 Apr09|Jun10

19. Spectrometer Solenoids The MICE guiding magnetic field is provided by superconducting coils. These magnets are all made following the same model, with the cold mass situated in a vacuum vessel and cooled to Liq. He temperature by cryo-coolers. The spectrometer solenoids are responsibility of LBNL Berkeley. Construction of the spectrometer solenoid for step II was complete one year ago. Magnet reached design temperature and (almost) design current (270A). However (July09) we burned out a High Temperature Superconducting (HTS) lead when trying to power at 238 A, indicating lack of cooling in this area. Magnet review took place in Nov 2009. Design was upgraded with an additional one-stage cooler and instrumented further. Much improvement was observed in the region of the HTS leads and thermal shield. Measurements were made to establish the heat loads and the Helium consumption – they are found higher than anticipated.With all 5 coils connected in series, the following current levels were reached during training: 165 A, 219 A, 238 A, 253 A and 257 A. After the 257A run it was found that the matching coil 2 was an open circuit..Presumably one of the cold leads is broken. The magnet is now being disassembled to examine the area where the failure is assumed to be.

20. Spectrometer Solenoid Configuration (June 2009) Cold head 1st stage HTS leads Fill & vent lines Radiation shield Cold mass Original version 5 coils! 4T, 40cm 

21. Spectrometer Solenoid Configuration (Mar2010) Single-stage cooler Thermal link Outfitted with new single-stage cooler HTS leads Matchingcoil 2

22. Status of spectrometer solenoid Mike Zisman Magnet 2 disassembly is continuing Tower has been completely removed

23. Status of spectrometer solenoid Mike Zisman Welds on vacuum vessel at AFC end have been cut and plate removed; weld on the other side also ground away at the end of last week • After cold mass removed, will be leak-checked • Thereafter, cold mass will be (carefully!) cut open in area of lead • feed-throughs towards quench protection system •  care will be taken to preserve condition of leads for inspection

24. It is becoming clear that the technological choice of cooling these rather large magnets with cryocoolers (cheaper and less space-consuming than a large fridge) requires near perfection in both design and execution. A number of steps are being taken -- To increase/stabilize personnel working on the magnets at both LBNL and RAL. New cryogenic engineer being hired at LBNL, expected on site in July. -- Estimating cost of large fridge (ongoing) -- A working plan will be drawn in consultation with the solenoid review panel who met by video in the week of May 2-5 and will meet again when more is known. -- a team from Fermilab Cryo+Magnets experts visited LBNL and vendor 13-14May. Full report being produced.

25. Status of spectrometer solenoid– next steps Mike Zisman First steps (1-2 months) examine thermal model in comparison with measurements to look for significant discrepancies Examine failure when cold mass is open Review magnet design and implementation Evaluate possible changes/improvements in terms of risk/benefit Then make recommendations on what changes to implement and finalize in consultation with review committeeand MICE TB – and go do it. This will take several months  new estimate will be made at the CM27 7-10 July 2010

26. See M. Zisman’s talk after step III (>Q3 2011) STEP IV Apr09|Jun10

27. See M. Zisman’s talk STEP V 2012-2013 Apr09|Jun10

28. See M. Zisman’s talk STEP VI >2013

29. OUTLOOK MICE is an important step in making a Neutrino Factory or a Muon Collider an option for the future of particle physics. The MICE collaboration is pursuing the goal of demonstrating that the technique of Ionization Cooling can be realized in practice, by constructing a cell of ionization cooling and measuring its performance in a variety of configurations. We have had a number of difficulties and so far have surmounted them all. At the moment: the spectrometer solenoids. We are taking data for step I, establishing that we have both intensity and beam quality to realize the measurements. The performance of the detectors and the beam is as good as in the proposal – so we believe that the goals of MICE will be achieved!