International Muon Ionization Cooling Experiment (MICE)

1. International Muon Ionization Cooling Experiment (MICE) Motivations: --Ionization cooling is an important ingredient in performance and cost of a neutrino factory --It has never been observed experimentally --It is a delicate design and engineering problem Goal --design, engineer, build a section of cooling channel that is part of a high performance neutrino factory design --put it in a beam and show that it works as expected (if not, understand why!) The beam never lies. This is a somewhat larger project that can be afforded by anyone of the worlds regions => International collaboration

2. n p m MICE An International Muon Ionization Cooling Experiment

3. 10% cooling of 200 MeV muons requires ~ 20 MV of RF single particle measurements => measurement precision can be as good as D ( e out/e in ) = 10-3 SC Solenoids; Spectrometer, focus pair, compensation coil Liquid H2 absorbers 201 MHz RFcavities Tracking devices: Measurement of momentum angles and position Tracking devices T.O.F. III Precise timing T.O.F. I & II Pion /muon ID and precise timing Electron ID Eliminate muons that decay

4. 10% cooling of 200 MeV muons requires ~ 20 MV of RF single particle measurements => measurement precision can be as good as D ( e out/e in ) = 10-3 Need same drawing for 200 MHz scenario!

6. MICE: what will it measure? Equilibrium emittance = 4200 mm. mrad(here) Cooling Performance = 16% Figure V.4: Cooling channel efficiency, measured as the increase of the number of muons inside an acceptance of 0.1 eV.s and 1.5 p cm rad (normalized), corresponding to that of the Neutrino Factory muon accelerator, as a function of the input emittance [31]. 28 MeV cooling experiment (kinetic energy Ei=200 MeV)

7. Steering committee: Europe: A. Blondel*1 , H. Haseroth, R. Edgecock Japan : Y. Kuno US: S. Geer, D. Kaplan2, M. Zisman *convener for coming year, 1 EU spokesperson, 2 US spokesperson charge: assemble « technical team » representing two regions in each of the following aspects. Web site: http://hep04.phys.iit.edu/cooldemo/ thanks to Yagmur Torun - torun@iit.edu

8. Participating institutes (In parentheses: contact person in each institute) Louvain La Neuve (G. Grégoire) CERN** (H. Haseroth) NESTOR Institute (L. Resvanis) University of Athens (L. Resvanis) Hellenic Open University (S. Tzamarias) INFN Bari (G. Catanesi) INFN LNF Frascati (M. Castellano, L. Palumbo) INFN Legnaro (U. Gastaldi) INFN Milano (M. Bonesini) INFN Padova (M. Mezzetto) INFN Napoli (G. Osteria) INFN Roma I (L. Ludovici) INFN Roma II (L. Catani) INFN Roma III (L. Tortora) INFN Trieste (M. Apollonio) ** pending the review of CERN activities in accelerator R&D which will take place in the framework of the LHC cost-to-completion analysis. KEK (S. Ishimoto) Osaka University (Y. Kuno) ETH Zurich (A. Rubbia) Paut Scherrer Institute (C. Petitjean) University of Geneva (A. Blondel) University of Zurich (A. Van der Schaaf) Imperial College London (K. Long) Rutherford Appleton Laboratory (R. Edgecock) University of Birmingham (J. Wilson) University of Oxford (G. Barr)

9. Participating institutes (ctd) (In parentheses: contact person in each institute) Argonne National Laboratory (J. Norem) Brookhaven National Laboratory (R. Palmer) Columbia University (A. Caldwell) Fairfield University (D.Winn) Fermi National Accelerator Laboratory (S. Geer) Illinois Institute of Technology (D. Kaplan) Lawrence Berkeley National Laboratory (M. Zisman) Michigan State University (M. Berz) Northern Illinois University (M. A. Cummings) Princeton University (K. McDonald) University of California Los Angeles (D. Cline) University of California, Riverside/Indiana University (G. Hanson) University of Chicago – Enrico Fermi Institute (K.-J. Kim) University of Illinois at Urbana-Champaign (D. Errede) University of Iowa (Y.Onel) University of Mississippi (D. Summers)

10. Technical Team leaders for the ionization cooling experiment ================================================ These nominees in charge of task forces have the following responsabilities: a) assemble the necessary team b) if possible recommend a technical solution c) foresee a description of the design/performance/cost estimate of their part.

11. a) concept development and simulations: Alessandra Lombardi (CERN)(Alessandra.Lombardi@cern.ch) Panagiotis Spentzouris (FNAL) (spentz@fnal.gov) Robert B Palmer (BNL) (palmer@bnl.gov) b) Hydrogen absorbers: Shigeru Ishimoto (KEK) (shigeru.ishimoto@kek.jp) Mary-Anne Cummings (Northern Illinois)( macc@fnal.gov ) c) RF cavities and power supplies Bob Rimmer (LBNL) (rarimmer@lbl.gov) Roland Garoby (CERN) (Roland.garoby@cern.ch) d) magnets Mike Green (LBNL) magreen@lbl.gov Jean-Michel Rey (CEA Saclay) e) particle detectors Vittorio Palladino (INFN Napoli) vittorio.palladino@na.infn.it Alan Bross (FNAL) bross@fnal.gov f) beam lines Rob Edgecock (RAL) edgecock@mail.cern.ch Claude Petitjean (PSI) claude.petitjean@psi.ch g) RF radiation Jim Norem (Argonne)norem@anl.gov Ed McKigney (IC London) e.mckigney@ic.ac.uk

12. Proposed agenda: 2001 Expose detectors to RF radiation (potential show stopper) write first description of experiment with two options US design (200 MHz) or CERN design (88 MHz) US simulate CERN scheme [and vice versa if possible] Evaluate availability and cost of main cost drivers: RF cavities / amplifiers/ power supplies/solenoids for each scheme evaluate beams + host labs 1st workshop 25-27 October 2001, CERN ! 16 Nov. 2001 ! Chose technology + host lab, write + submit LETTER OF INTENT 2002 Technical proposal summer 2004 1st beam (debugging of spectrometers)

13. MICE Item BASELINE SCENARIO ALTERNATIVE(s) COMMENTS 200 MHz 88 MHz .. Difficult to present 88 MHz in present CERN financial situation. 88 MHz Nufact study should continue! RF frequency SFOFO with focus pairs One 4-cell cavity first then 2 4-cell cavities Single flip solenoid Question: can same set of magnets be used with/without flip? Should we foresee stronger than minimum mag field to explore stronger focusing? Sealed with He cooling circuit (KEK design) Tunable thickness? L-H2 absorbers With recirculating H2 circuit Experimental solenoid 60 cm(?) diameter, 3 T 120 cm long, DB/B=1% active shield 30 cm diameter active area .. 40 cm diameter with slits for detectors .. iron shield B field should be matched to that of cooling cell

14. MICE Item BASELINE SCENARIO ALTERNATIVE(s) COMMENTS PSI Beam line exists, can be used for particles, with P < 250 MeV/c without delay. New collaborator! RAL quite motivated. Host lab RAL PSI mE1 with energy 100-300 MeV can begin with 100-200 MeV Requirements well defined Beam beam preparation: 10 meters after last collimator Experimental area > 15 X 4 m2 Lateral space needed has not been investigated carefully!, foresee some margin. Space required Will request interaction with host labto prepare proposal Safety Liquid Hydrogen + Magnetic field spectrometers In vacuum/helium with double window Loss of resolution in air to be evaluated In air with triple window around hydrogen Noise issue must be solved before final design. Interest in thin pixel detectors for LHC upgrades Silicon pixel may be needed if noise level too high TPC- G ? Scintillating fiber planes > 4 planes with 3 coord each side Trackers PSI beam very clean at low energy PID upstream TOF with scintillators Fast cerenkov Requirement not entirely clear Downstream PID Active absorber Threshold Cerenkov

16. PSI The MICE Letter of Intent (LOI) was presented to the Research committee for the Ring Cyclotron of the Paul Scherrer Institute (PSI) on Tuesday 8 January 2002; public presentations were made to the users meeting. (I was told by the chair of the committee that the talks of Dan Kaplan and Klaus Hanke were excellent and answered many of the questions the committee and referees had, such as why is this experiment important for the Neutrino Factory R&D.) The Committee acknowledged the receipt of the LOI. On request by the PSI management it did discuss the matter. (conclusions given orally by the chair; from my notes… no written statement yet) 1. The Neutrino Factory project offers exciting physics and the proposed experiment fits well within the project. The strategic goal of the experiment, which is to test a crucial part of the Neutrino Factory design, was recognized. 2. The committee supports the aim of the experiment but expressed questions to the PSI management as to whether it is appropriate for PSI to embark in it. The concerns expressed by the committee were as follows a) No formal organization (I.e. laboratory) is behind the project. b) Hosting MICE will be a non-negligible investment for PSI; it is not realistic to believe that PSI would not have to provide day-to-day support for the experiment, c) the requested technical help to prepare a proposal and in particular the overview of safety aspects, which need to be taken *very* seriously by the host lab, constitute already an important commitment. d) PSI should consider the impact that this experiment might have on the ongoing research program e) It is not clear to which extent this R&D is important for the future of the laboratory (does PSI want to play a major role in the Neutrino Factory? This is a management decision!) f) PSI is probably the best place to host the experiment, but not the only one.

17. PSI Next steps: PSI management will meet and evaluate if there are sufficient interest and resources in the LAB to host and support the experiment. Discussions are taking place with the management of RAL to which the LOI was also sent, with the aim of finding a solution by which the experiment can take place. A formal answer to our requests will be given in about a month.

18. From Ralph Eichler (PSI director), 23 january 2002, 7:27:55 Subject: MICE Dear Alain, Here is the status of decision making on the muon cooling: 1. Muon cooling is essential for muon collider (no way out). A muon collider is very far in the future and most likely the radiation protection against neutrinos is a show stopper. 2. Three ideas for a neutrino factory exist (Japan, RAL, yours). Two of them need little or no cooling. Your Proposal need the largest cooling. 3. I called John Wood director of RAL. We agreed, the RAL and PSI should collaborate in a muon cooling experiment. RAL will discuss internally if they want to have the experiment at RAL or PSI (time frame 2 weeks). In case the cooling is at RAL, I offered to provide next year our superconducting muon channel n° 2 (5m 5T field presently in muE4). I have the impression that RAL is willing to inject much more manpower into the project than PSI is able to provide. I keep you informed of the next steps With best regards, Ralph

19. Answers (A.B.) 1. Muon cooling is essential for muon collider (no way out). A muon collider is very far in the future and most likely the radiation protection against neutrinos is a show stopper. The neutrino radiation issue for muon cooliders comes up at 3-4 TeV E.c.m. At lower energies, relevant to the machines that have the unique capability of s-channel studies of Higgs bosons (SM and SUSY Higgses) the neutrino radiation is not an issue. 2. Three ideas for a neutrino factory exist (Japan, RAL, yours). Two of them need little or no cooling. Your proposal need the largest cooling. There are scenarios for neutrino factories in US, Japan and CERN. The only project that has been fully evaluated and costed is the US one, and it uses cooling. The CERN scheme relies even more on cooling. The Japanes scheme is based on a series of several FFAGs which have not been costed and in which, in a way similar to the “ring coolers”, it is an unsolved problem how to inject or extract the beam. Having no cooling implies very large FFAG magnets – the horizontal aperture is large by construction, but not the vertical one – which could raise the cost considerably. In fact there are studies on how to implement cooling in an FFAG scheme, very similar to ring coolers; the hardware needed for such cooling is very similar to that discussed for MICE. 3. I called John Wood director of RAL. We agreed, the RAL and PSI should collaborate in a muon cooling experiment. RAL will discuss internally if they want to have the experiment at RAL or PSI (time frame 2 weeks). In case the cooling is at RAL, I offered to provide next year our superconducting muon channel n° 2 (5m 5T field presently in muE4). I have the impression that RAL is willing to inject much more manpower into the project than PSI is able to provide. Great! Thank you very much for handling this so seriously!

21. This is the beam line E4 which will be dismantled at the end of 2002 This is the beam line E1 where MICE could be installed 2002

22. RAL… • In order to satisfy the requirements of the cooling experiment the following upgrades to the beam are required: • ·      The pion peak must be moved up to at least 450 MeV/c; • ·      The background to the muons must be reduced by a large factor; • ·      The rate of muons must be increased by increasing the length of the pion decay channel. • Proposed upgrade • The beam required by the cooling experiment can be provided if the HEP Test Beam is upgraded by: Decreasing the angle at which particles are captured into the beam line: This will increase the rate of particles entering the beam line as well as moving the peak of the captured momentum to higher values; Implementation of a solenoid pion decay channel: The length of the solenoid, typically 5-6m, allows a significant fraction of the input pions to decay therein, and the high longitudinal magnetic field (~5T) captures the decay muons with high efficiency thereby increasing the muon intensity. Simulations of these changes in the layout of the beam are in hand.

23. MICE and the LHC cost to completion crisis It was anticipated that CERN would have very little resources to devote to the cooling expt., the LOI only ascribed the value of a refurbished RF power source (4 MW, essential), which was assumed to come in a couple years (2004 or so) CERN now has to concentrate on the completion of LHC, and the material budget for Neutrino Factory has been radically cut (despite your protests, thanks!). The R&D is assumed to be focused on the proton driver SPL, and possibly the target and horn(?). At the same time, the director of accelerators (Carlo Wyss) has proceeded to convene a European Muon Coordination and Oversight Committee (EU-MCOG) that will be composed of leading personalities in Europe. CEA- Saclay 2 members (Mosnier, Pierre) IN2P3 2 members (Lieuvain, Katzanevas) INFN 2 members (Napolitano, Pisent) RAL 2 members (Peach, NN) GSI Darmstadt 2 members (Hofmann, NN) Julich, PSI, Novosibirsk, to be decided, DESY declined This committee will review the R&D towards future neutrino beams and define a first set of goals. It will also coordinate a fund request from the European Union. Maybe this not all so bad after all. Lets go on.

24. 2002 The schedule of activities can be envisaged as follows, assuming all milestones are passed successfully. 2002: Preparation of proposal and fund raising ·IIntegrated simulation of experiment including beam, detectors and cooling cells CRITICAL ·Evaluation of possible sources of systematic errors ·Investigation of low equilibrium emittance lattice and of the compatibility with ring coolers ·Continuous comparison of the 200 MHz and 88 MHz scenarios ·Test of detectors in X ray environment (already underway) CRITICAL and choice of tracking devices ·Operation of 88 MHz cavity at CERN and of the test facilities at Fermilab ·Continued development of liquid hydrogen absorbers Development of alternative schemes for absorbers ·Competitive design and cost estimates for the solenoids ·Constitution of a collaboration structure and more detailed distribution of tasks and financial responsibilities ·Evaluation with the host laboratory of the requirements on space, facilities, safety and radiation issues, and infrastructure Submission of proposal in the course of 2002.

25. . Observed dark currents in 800MHz cavity in lab G. The cavity could not be run at a gradient higher than 5 MV/m without emitting one electron or more within a time window of 20 ns. (i.e. 10-8 mA) Q. Is this the right figure of merit? Better probably: observed noise rate in actual detector near the cavity.

26. => 6.70 MV/m => 4.65 MV/m .43 X 4 cells = 1.7 m  11.5 MV for 1X 4 = 6.70 MV/m 16 MV for 2X4 = 4.65 MV/m Is this correct?

27. Simulations Needed now: understand what is the noise level that affects the performance of each particular proposed detector scheme. Understand tolerances on spectrometer solenoid Needs simulation and reconstruction including noise and inefficiencies. We have now DWARF (Patrick Janot) rather fast fortran code that contains a rudimantary helix fitting code. Not impossible to implement Exact field map (Bx,y,z of x,y,z) Noise hits Pattern recognition? GEANT4 (Yagmur Torun) Multipurpose tracking code. Noise hits and pattern recognition and fitting code need to be added by hand too. Will allow detailed detector response (for Cerenkov and e/mu absorber study)

28. PRIORITIES • Find a home for the experiment • Understand the X ray issue and quantify it in terms of • particle detector performance • 2.’ Develop reconstruction with noise and efficiencies • 3. Chose detectors and finalize magnet parameters • 4. Establish technical specs and cost estimates • 4’ Distribute contributions and begin fund hunt mission • 5. write proposal