Status of the MICE Sci Fi Simulation Edward

Status of the MICE Sci. Fi Simulation Edward Mc. Kigney Imperial College London

• General Status Outline – Description of current reconstruction scheme – Additional modifications required • Review Panel Questions and Responses • Current Results – Multiplexing – Inefficiency from dead fibers not completed • • Cross Talk for MICE Sci. Fi A brief summary of Mu. Scat Tracking A brief summary of D 0 Tracking Conclusions

Track Parameters y (x 0, y 0) 0 r B x z

Space Point Reconstruction 1. For each tracker station, all fibers above the 2. 0 PE threshold are selected for processing 2. Doublet Clusters of adjacent fibers are formed 3. Space points are formed from the intersection of doublet clusters 4. Space points with at least one doublet cluster in each view are passed to the pattern recognition Space Points Accepted Space Points

Seed Helix and Road Definition 5. Sets of space points from three stations are used to define a helix, and if the momentum found is compatible with the beam, a search of the other stations is performed 6. Any points with a 2 below the threshold (100) are passed to the track fit

Energy Loss Correction in the fit • For a given set of track parameters, the track is propagated from the origin to the first plane, and the intersection of the track and plane is calculated, for comparison with the measured values • Mean energy loss through the detector plane is calculated • A new set of track parameters is calculated, based on the energy loss • The process is repeated

Helix Fit 7. A helix fit is performed using one space point from at least four stations 8. The track with the best track probability is kept

Additional Modifications to Tracking • Reconstruction of tracks with three triplet hits and two doublet hits

Questions from Review Panel • Fibre tracker • It seems essential to perform a full simulation of a tracker with five planes, including nominal inefficiency and assessment of the redundancy by simulation of the loss of readout— dead fibres. The impact of noise and misalignment should also be assessed. What is the status of this simulation? • Because of the cost saving by multiplexing, it is important to repeat the simulation in a realistically multiplexed arrangement. • Will the main alignment be derived from “straight through” muons? • Some documented information on the performance of the fibre tracker in the MUSCAT experiment would be useful.

Response • The following functionality has been implemented and tested – Simulation of a five station tracker – Reconstruction of tracks in five station tracker with 4/5 and 5/5 stations hit, including energy loss correction – Multiplexing of fibers per VLPC, up to 7 – VLPC noise • Implemented, testing in progress – Dead VLPCs and/or fibers – Misalignment of stations (displacements implemented, no rotations yet)

Alignment Scheme • Alignment comes in four parts – Good mechanical alignment and repeatability engineered in from the beginning – Survey for initial alignment – Cosmics for final alignment (E > 1 Ge. V) – Cross check using straight through muons • Final test is measurement of residuals from five point tracks

Performance Study List • Comparison case – No MUX, Dead Channels (beam and cosmics) – Nominal MUX, Dead Channels(beam and cosmics) • • • RF Background series (beam, nominal tracker) MUX series (beam, nominal tracker*, RF Bkg) Dead Channel series (beam, nominal tracker*, RF Bkg) Alignment series (cosmics, nominal tracker) Two parameter series as appropriate Alex Tapper(IC), Julia Sedgbeer(IC), Akram Kahn (Edinburgh) * All nominal except parameter varied for the series

Resolution for Transverse Momentum (pt) Distributions from the Berkeley meeting

Multiplexed pt Resolution multiplexing 7 fibers together reduces pt resolution by a factor of about 1. 5 compared to the value presented at Berkeley Thanks to Dave Colling at IC for generating these samples on the Grid

Cross Talk for MICE Sci. Fi • Use 3 HF scintillator at high concentration (5000 ppm) – 3 HF as primary fluor gives 95% of light and no cross-talk • Cross Talk in optical system zero by engineering design – No open paths for light to get from one fiber to another

Summary of Mu. Scat Tracking • Mu. Scat is now set up at TRIUMF, and the detector has been calibrated • Full reconstruction, run control, data acqusition and data quality monitoring is in place and has been tested • Data taking starts in the middle of April and continues into may • Results are expected for Nu. Fact 03

Mu. Scat Calibration All channels have been calibrated using photo-tube noise events in a self triggering configuration Calibrated Single PE Peak

Cosmic Ray Angular Distributions

Mu. Scat Cosmic Ray Events An Air Shower? A Muon?

Summary of D 0 Tracking • Tracking Performance – Doublet layer hit efficiency is 98 -99% – Position resolution is 96 microns (preliminary) • Dead Channels – <200 out of 77, 000 compromised fibers (~0. 25%) – ~190 out 77, 000 compromised VLPCs (~0. 25%) • Noise – Intrinsic VLPC noise << X-ray background (see next slide)

VLPC Performance (A. Bross) VLPC (Visible Light Photon Counter) – Cryogenic APD @ 9 K VLPC ® HISTE VI – High QE » 80% – Low noise <5 X 104 Hz (@» 1. 0 pe) – High Rate capability >40 MHz – High production yield » 70% (vs. 27% projected)

Conclusions • Most of the functionality to answer the Review Committee’s questions has been implemented • Submitting jobs to the Grid is now possible, and the process is being automated • Sci. Fi performance studies are underway