Tracker Summary Alan Bross MICE CM17 CERN February 25, 2007

Scintillating fibre tracker  The scintillating fibre tracker reconstructs muon tracks before and after the MICE cooling section in 4 T magnetic field to measure the relative change in emmitance of the muon beam  The tracker consists of five planar scintillating-fibre stations  Each station is composed of three planes of scintillating fibres laid out with 120 degrees radial spacing  Each fibre plane is comprised of a ‘ doublet-layer ’ in which the fibres in the first layer of the doublet are interleaved with those in the second

Production Status  Fiber Mirroring Is COMPLETE  Mean R = 75% RMS=4%

Ribbons  Production Ribbons u COMPLETE u 48 “good” ribbons were produced s 16 stations wort

Fiber Stations  Build stations u Prepare carbon fibre station frames s All carbon fibre stations ready to be machined u Prepare 450 station connectors s 169 station connectors made so far  Construct trackers u Prepare assembly jig u Prepare framing tools

Station Production  Station five built u Will be Fermilab in a few weeks  Full production started on 15 Jan u Station six ready for cutting/polishing u Station seven underway s - view X/W bundled and connectorised; ready for gluing s - view V bundled

T. Matsushita 7 Station 5 Test with cosmic ray Polish with new diamond fly cutter Measure uniformity of height (z) of station

Station 5 Testing Proposal  Options were discussed at the recent tracker workshop.  Solution chosen is: u Waveguides and Station 5 will be shipped to Fermilab. u Cosmic ray test rig will be setup at Fermilab using D1 and D2 from KEK test (currently being tested with some PMTs from Imperial at RAL). u Once cassette will be used on whatever cryostat is available at the time at D0 to readout and the DAQ spreadsheet already used to start cassette charcaterisation will be used.  Once sufficient hardware exists for operating two parallel systems (including UK vs US power) one system will be sent to Imperial and will be used there (after Station 5 test).

Station Production Schedule  Will parallelize production line after the meeting u Help from FNAL starts mid March ETA of the first five stations: end of march

Lab Layout at IC

Source Scan Co57 (122keV photon, O(10 2 ) events) self-trigger on the front end board micro-positioning XY stages to excite 1 channel at a time (1.5 mm width) relative Light Yield for all channels + fibre uniformity check Cosmic Transportable light tight box (will be shipped for station 5 test at FNAL) External trigger using scintillation counters Absorber to filter out < 200MeV/c  extrapolate LY at MICE Test Methods counter0 cosmic box absorber counter1

G.Barber Mice Tracker Mechanical Progress Cern February 2007 Space Frame The components that are used to construct the space frame are nearly all at Imperial we are just a few pieces missing and Peter has a list of these. Even so we have enough to start production of the space frames. New Foot Design Gluing Fillet Design

G.Barber Mice Tracker Mechanical Progress Cern February 2007 Space Frame Tooling The jigs that align the space frames have been modified/re-designed. This will not only accommodate the new foot design but will also allow us to match the new station to station pitch. This work has been carried out by Peter Ford at RAL and he has also produced a set of production drawings.

G.Barber Mice Tracker Mechanical Progress Cern February 2007 Waveguides - Internal

Waveguides - External

Cryo  Production cryostats: u All parts in house s Except for Oxford controllers –Due Mid-March u First Production Cryostat Complete and under test s Uses cassettes 107 and 111 u Unfortunately there are some issues with Cryostat #1 s More in bit  We are having some “issues” with US vs. UK voltage u Cryostat lid heater control circuitry was not UK compatible u We now have the proper electronics in hand for all Production cryostats s #1 already fitted s Prototype cryostat will have to be retro-fitted before it is shipped to IC

 Production Cryostat #1

Production Cryostat #1 – Cooldown #2  Second Cooldown u Cassettes operating at 7.8K (no left-right asymmetry)  Still a little (  0.5K) warm (expected from Prototype performance u Temperature control/stability excellent 2mK rms

Production Cryostat #1 – Cooldown #2  However, we are currently operating with US Voltage u 60 Hz  In the UK we have to derate the system due to 50 Hz operation (from Sumitomo load curves) u At 50 Hz the cassettes will be running approximately 1K higher – 8.8K s This leaves very little margin s This is with a fresh Cold-Head s Would have expected from Prototype Cryo -  Options u Provide 60 Hz in MICE Hall s Expensive u Run hotter (9.5K) s Will characterize cassettes at both 9 and 9.5K to evaluate this option  We can certainly start at 50 Hz

AFE-IIt Boards for MICE D0 has all necessary boards for upgrade. We need about 1 or 2 new AFE-IIt boards per week for next couple months. –Michael Wojcik is performing these MICE-specific tests. –MICE requires 16 AFE-IIt boards + 9 spares.

Firmware Modification Overview for Increasing Data Rate Enable TriP-t pipeline to collect data during digitization. Reduce digitization time for channels below threshold (zero- suppression) –6 cycles for channels above threshold –1 cycle for channels below threshold Use TriP-t 4-level analog buffer to enable data collection during digitization. Much progress has been made in modifying the firmware to effect these changes, but Key Question: Will the AFE-IIt boards with the TriP-t chips work with these changes? Goal – 600 kHz muon collection rate with low dead-time

Where we were. (Digitization time ~ 5600 ns) Fraction of Recorded Muons Digitization Time (ns) No Buffering 1-level Buffering 2-level Buffering 3-level Buffering 4-level Buffering 600 kHz Muon Rate

No Buffering 1-level Buffering 2-level Buffering 3-level Buffering 4-level Buffering Where we are Fraction of Recorded Muons Digitization Time (ns) 600 kHz Muon Rate

Where we’d like to be Fraction of Recorded Muons Digitization Time (ns) No Buffering 1-level Buffering 2-level Buffering 3-level Buffering 4-level Buffering 600 kHz Muon Rate

KEK Test Beam - Track Reconstruction Assuming “ Uniform B-Field ” and “ NO scattering ” Chi2 to be minimized –Input: x i, y i (i=1,4) –Output: x 0, y 0, p 0, R, L –Degree of freedom: 8-5=3 x 0, y 0 00 #4 #3 #2 #1 R

Summary of Residual for Y Fitted_Mean MC DATA Fitted_Sigma 250MeV/c 325MeV/c 400MeV/c

Conclusions  First Tracker under Test in May/June  Second follows soon after  Ready for Beam in August  See you in Didcot u Don’t get Oprah Angry!

Results of T585 Stability of VLPC –There is no problems. Hit efficiency –This is the same as expected by MC. Tracking efficiency Pz resolution Pt distribution