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