Transcript First Results from Tracker 1  Cryostat Commissioning  AFE/VLSB Firmware and Readout  Cosmic Ray Setup  Tracker Readout  Software  Trigger Timing Scan  Alignment 

First Results from Tracker 1
 Cryostat Commissioning
 AFE/VLSB Firmware and
Readout
 Cosmic Ray Setup
 Tracker Readout
 Software
 Trigger Timing Scan
 Alignment
 Light Yield
 Next Steps
M.Ellis - VC113 - 17th July 2008
1
Cryostat Commissioning
 Both cryostats cooled down very well and
reached a temperature that allows all 4
cassettes to operate at 9.0 Kelvin.
 The lid heater alarms and VESDA smoke
detection system have been hooked up to a
relay that will kill the AFE power if any of
the three alarm.
 An auto-dialler will call an expert (or the
MOM) if any of the above alarms occur, or
if either of the insulating vacua start to
degrade.
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2
AFE / VLSB Firmware
 New AFE and VLSB firmware
from Fermilab is being used
for the readout.
 An additional VLSB is providing
an encoded clock signal that is
fanned out to all 8 AFE
boards.
 The readout is operating
asynchronously, with the
trigger coincidence signal being
vetoed by the master VLSB to
only allow a trigger to be
produced in the correct live
M.Ellis - VC113 - 17th July 2008
windows.
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Cosmic Ray Setup
 The 25 waveguides were connected
and the cassettes made light tight.
 At the moment there is a 2 inch
layer of lead under the tracker to
act as a momentum filter.
 The coincidence of two trigger
scintillators (one above the tracker,
one underneath the tracker and a
layer of lead) provides the external
trigger (which is a bit noisy).
 Some new trigger scintillators are
being prepared at Fermilab which
should increase the trigger rate and
the trigger efficiency.
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4
Tracker Readout
 At the moment we are using the
Excel/Visual Basic DAQ developed at
Fermilab.
 Hideyuki is working on a Linux based
AFE initialisation code.
 Once that is working, we will check
that the data taken looks the same
and start to move to a Linux based
AFE initialisation and DATE DAQ for
readout. M.Ellis - VC113 - 17th July 2008
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Software
 The decoding and calibration files have been
committed to G4MICE and the necessary
unpacking code for the current data format.
 A new application – “R8CosmicTest” has been
added which reconstructs the data and
creates ROOT histograms and event display
files for viewing using HepRApp.
 All plots in this talk can be reproduced by
checking out the most recent version.
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Trigger Timing Scan
 Need to get the delay between cosmic ray passage
and AFE trigger signal correct at the level of 1020 ns.
 Scan over a range of delays, take data for a day
and find delay with maximum light yield.
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Trigger Timing Scan - Results
Light Yield for each Station
Average Light Yield for All 5 Stations
Delay chosen: 862 ns
Filled square – station 1
Triangle up – station 2
Triangle down – station 3
Open circle – station 4
Open square – station 5
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Alignment
 The alignment started with the nominal
values from the tracker design for the
station spacing, central fibres, etc.
 These were fed into G4MICE and
triplet residuals and tracking residuals
used to spot any misalignments or
inconsistencies.
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Triplet Internal Residuals
Stations 1 – 4 have residuals centred
near 0 with no need for any alignment
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Triplet Residuals – Station 5
Station 5 before adjusting the nominal values
Station 5 after adjusting plane X
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Station Alignment
 Will check station spacing with Coordinate
Measuring Machine (CMM) data, but for
now assume the spacing is exactly as
designed.
 At high momentum (i.e. no MCS), expect
residuals to have an RMS of ~ 430 mm in
X and ~ 497 mm in Y.
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Track Residuals
X – expect 430 mm, see 466 mm RMS
Y – expect ,497 mm, see 549 mm RMS
Implies misalignments of order 100 mm
TRD Spec for Tracker alignment: 70 mm
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Light Yield
 Light yield determined by plotting the
distribution for each plane and each station
(integrating over planes in a station) for
clusters that were included in a good track.
 Some features (narrow peaks) in the plots
for individual planes/stations are due to
overflow of the ADC.
 Due to variations in the gain of the
cassettes, these peaks move around as a
function of plane/station.
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Light Yield – All Stations
Light Yield: ~ 11 PE
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Next Steps
 Add another layer of lead and continue
data taking at the optimum trigger
delay.
 Use CMM data to update station
spacing and possibly transverse
positions.
 Study light yield and efficiency for
each station and each plane, and if
sufficient statistics, as a function of
position on the plane.
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Finally – 100 Events with 5 point Tracks:
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