1 Status of the MICE SciFi Tracker Malcolm Ellis Imperial College London Tuesday 9 th March 2004

2 Outline MICE and its tracker Sci Fi design Prototype construction Prototype operation Light yield Further work

3 Muon Ionisation Cooling Experiment For a Neutrino Factory or Muon Collider it is necessary to take a large emittance beam and cool it for acceleration before the muons decay. The proposed solution is ionisation cooling. The purpose of the MICE experiment is to measure the cooling achieved by a short section of cooling channel and demonstrate that it is possible to operate such a channel.

4 The MICE Collaboration Approximately 150 Physicists 41 Institutes 3 Continents: –US –UK/Europe –Japan

5 Ionisation Cooling Principle Practice Study II

6 MICE at RAL

7 MICE Tracker Required to measure muon track parameters to enable a measurement of the emittance reduction (~10%) to an absolute precision of 0.1% Tracker must be capable of picking out muons with high purity from the intense background produced by the RF cavities. Baseline solution – Scintillating Fibres, read out with VLPCs (with timing information).

8 Sci Fi Group Japan M. Yoshida, K. Yoshimura KEK Y. Kuno, H. Sakamoto, A. Sato, Osaka US A. Bross, J. Estrada, R. Rucinski, P. Rubinov FNAL D. Kaplan, Y. Torun Illinois Institute of Technology G. Hanson, A. Klier, Riverside X. Yang UCLA UK P. Kyberd, A. Khan Brunel L. Tong Edinburgh G. Barber, M. Ellis, K. Georgiou, R. Goncalo, K. Long, J. Sedgbeer, A. Tapper Imperial College London P. Cooke, R. Gamet Liverpool

9 Sci Fi Design A tracker (there will be two) contains 5 stations. A station measures one 3D space point using 3 views (V,X,W) oriented at 120 degrees. One view is made from a ribbon of micron fibres ganged into 213 groups of 7.

10 A MICE Sci Fi Tracker

11 Prototype Construction Fibre supplied by Kuraray Fibre ribbons assembled at Fermilab Fibres “connectorised” (7 fibres -> 1) and planes aligned and constructed into stations in the UK Stations and support structure shipped to Fermilab – 3 station tracker assembled Tracker prototype installed at D0 – cosmics

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13 Prototype Operation Cosmic ray trigger consists of two 30x30cm scintillators with some lead as a momentum filter. Trigger signal from cosmic rig causes VLPC test- stand read out (if it is in time). Cosmic ray data taken in October 2003 and currently (for next few weeks). Aim to have measurements of light yield, position resolution and dead channels in order to satisfy collaboration that this tracking option will be adequate for MICE.

14 Our First Cosmic Ray Track

15 Light Yield PTP PTP

16 Efficiency Efficiency measured in centre station only: PTP+2500 – 98.6% PTP+3500 – 96.3% PTP+5000 – 94.0%

17 Continuing Work Take more data to determine light yield and efficiency as a function of scintillator type. Results from cosmic ray test need to be fed into G4MICE to predict/confirm performance of tracker in MICE. Update design and construction/QC plans in light of experience with prototype and advice from D0 experts.