Alain Blondel MICE: Constraints on the solenoids 2.Field Homogeneity: or ? this will be dictated by the detector requirements. TPG will be more demanding (uses the field actively as guide for drift) => STUDY to be made! 1.Dimensions: we decided in Chicago in February that the useful spectrometer field region should be 100 cm long and 30 cm diameter. the inner bore should be 40 cm 4. WHICH CONFIGURATIONS? Personal thoughts……..for discussion: 3. Matching: MICE should be magnetically transparent. This requires a matched magnetic system for a certain number of configurations  availability of the corresponding KNOBS  Movable elements

Alain Blondel T.O.F. III Precise timing Electron ID Eliminate muons that decay Tracking devices: He filled TPC-GEM (similar to TSLA R&D) and/or sci-fi Measurement of momentum, angles and position T.O.F. I & II Pion /muon ID precise timing 10% cooling of 200 MeV muons requires ~ 20 MV of RF single particle measurements => measurement precision can be as good as  out /  in ) = MHz RF cavities Liquid H2 absorbers or LiH ? SC Solenoids; Spectrometer, focus pair, compensation coil

Alain Blondel STEP I: we get the muon beam In this first phase we define the beam tunings, composition, settings for both mu+ and mu- as a function of momentum. needed: beam (!) TOF, trigger some DAQ two SCI FI arrays or beam chambers PID 10 m

Alain Blondel In this step we 1. turn on and map the first solenoid 2. study the acceptance and the required thickness of the diffusers 3. debug the Tracker 4. verify the matching of TPG with Sci-fi or beam chamber 5. debug track identification devices 6. (MEASURE BEAM EMITTANCE IN SOLENOID!) Step II: the first solenoid arrives, the tracker arrives a few weeks later. needed: solenoid and all services magnetic measurement system tracking devices + - and

Alain Blondel Step III: TWO spectrometers At this step we: -- Turn on and map the second solenoid -- Debug Spectrometer # 2 -- Measure  in  out and the ratio -- Field reversal is important for E ^ B effects THIS IS A VERY IMPORTANT STEP : THESE RESULTS WILL BE PART OF THE FINAL ONES (Systematics on  in  out ) + + and - - do we need + - ? -- can insert a number of materials to measure e.g. dE/dx vs scattering angle correlation

Alain Blondel Step III- B: TWO spectrometers -- can insert a number of materials to measure e.g. dE/dx vs scattering angle correlation At this point we might want to bring in an absorber and measure its properties in this simpler configuration + +

Alain Blondel Step IV: TWO spectrometers and the LH2 absorber At this step we: -- Turn on and map the flip pair -- Match the system -- Measure  in  out and the ratio -- for full AND empty absorber. -- for ++ AND +- configuration -+ or + +

Alain Blondel Step V: first cooling cell At this step we: -- Turn on and map the flip pair -- Match the system -- Measure  in  out and the ratio -- for full AND empty absorber. -- for ++ AND +- configuration + or with flips without flips

Alain Blondel Step VI: low beta study See; Palmer – Fernow Note – or talk at the October 2001 Workshop at CERN. Limit is: current X 2 in flip coils and zero in coupling coil.

Alain Blondel Step VI: low beta study + + with flips this has to be completely re-matched…. and re-mapped! Quite an operation…

Alain Blondel Other momenta? MICE could certainly map the acceptance as a function of beam momentum for a given magnetic setting. Off-nominal-momentum performance may be sub-optimal (?). Should we try MICE matched for lower/higher momentum as well? more/less cooling!

Alain Blondel Step VII The full two-cell MICE ibid. sensitivity will be better since volts will be higher. can try various settings of polarities and absorbers (full / empty) and of absorber thicknesses (to match available RF or beam momentum)

Alain Blondel Preliminary conclusions for discussion 1.It will be necessary to have enough knobs to vary the magnetic configuration to adapt to the various avatars of MICE 2.The various components of the magnetic channel will have to move along the experiment 3. There will be a lot of magnetic measurements to do! (I must have been a mice (sorry, mouse) in one of my previous lives)