Tracker Summary
Alan BrossMICE 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%
Frequency
0
50
100
150
200
250
300
0.6
0.62
50.
650.
675
0.7
0.72
50.
750.
775
0.8
0.82
50.
850.
875
0.9
0.92
5M
ore
Frequency
Ribbons
Production Ribbons COMPLETE 48 “good” ribbons
were produced 16 stations wort
Fiber Stations
Build 15 - 16 stations Prepare carbon fibre station frames
All carbon fibre stations ready to be machined Prepare 450 station connectors
169 station connectors made so far
Construct trackers Prepare assembly jig Prepare framing tools
Station Production
Station five built Will be tested @ Fermilab in a few weeks
Full production started on 15 Jan Station six ready for cutting/polishing Station seven underway
- view X/W bundled and connectorised; ready for gluing
- 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: Waveguides and Station 5 will be shipped to Fermilab. 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).
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 Help from FNAL starts mid March
ETA of the first five stations:end of march
Lab Layout at IC7430
pc table 1
work table
He
3500
Rack
CompressorVLPC
Cryostat
pc table 2
ChillerCosmic Setup
xv
wx
v
w
Source Scan
• Co57 (122keV photon, O(102) 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 andhe has also produced a set of production
drawings.
G.Barber Mice Tracker Mechanical Progress Cern February 2007
Waveguides - Internal
Waveguides - External
Cryo
Production cryostats: All parts in house
Except for Oxford controllers– Due Mid-March
First Production Cryostat Complete and under test Uses cassettes 107 and 111
Unfortunately there are some issues with Cryostat #1 More in bit
We are having some “issues” with US vs. UK voltage Cryostat lid heater control circuitry was not UK
compatible We now have the proper electronics in hand for all
Production cryostats #1 already fitted Prototype cryostat will have to be retro-fitted before it is
shipped to IC
Production Cryostat #1
Production Cryostat #1 – Cooldown #2
Second Cooldown Cassettes operating at 7.8K (no left-right asymmetry)
Still a little (0.5K) warm (expected from Prototype performance Temperature control/stability excellent 2mK rms
Production Cryostat #1 – Cooldown #2
However, we are currently operating with US Voltage 60 Hz
In the UK we have to derate the system due to 50 Hz operation (from Sumitomo load curves)
At 50 Hz the cassettes will be running approximately 1K higher – 8.8K
This leaves very little margin This is with a fresh Cold-Head Would have expected from Prototype Cryo -
Options Provide 60 Hz in MICE Hall
Expensive Run hotter (9.5K)
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 Overviewfor 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)
1000 2000 3000 4000
0.2
0
0.4
0.6
0.8
1.0
Fraction of Recorded Muons
Digitization Time (ns)
No Buffering
1-level Buffering2-level Buffering3-level Buffering4-level Buffering
600 kHz Muon Rate
No Buffering
1-level Buffering2-level Buffering3-level Buffering4-level Buffering
Where we are.
1000 2000 3000 4000
0.2
0
0.4
0.6
0.8
1.0
Fraction of Recorded Muons
Digitization Time (ns)
600 kHz Muon Rate
Where we’d like to be.
1000 2000 3000 4000
0.2
0
0.4
0.6
0.8
1.0
Fraction of Recorded Muons
Digitization Time (ns)
No Buffering
1-level Buffering2-level Buffering3-level Buffering4-level Buffering
600 kHz Muon Rate
KEK Test Beam - Track Reconstruction
• Assuming “Uniform B-Field” and “NO scattering”• Chi2 to be minimized
– Input: xi, yi (i=1,4)
– Output: x0, y0, p0, R, L
– Degree of freedom: 8-5=3
2
2fiti
2
2fiti
i
2 )y(y)x(x
]/LRcos[zxx 0ifit 0
/(0.3B)p R T
/(0.3B)p L L
]/L[zRsin yy 0ifit 0
x0, y0
0
#4
#3 #2
#1
R
Summary of Residual for Y
Fitted_Mean
MCDATA
Fitted_Sigma250MeV/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
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