Transcript TPG status

Status of the TPG
B. Bene, A. Blondel, E. Gschwendtner, J.-P. Richeux, R. Sandstrom, O. Voloshyn
Universite de Geneve
S. Giani, J.-C. Legrand, R. de Oliveira, L. Ropelewski, F. Sauli, M. Van Stenis
CERN, Geneva
M.G. Catanesi, E. Radicioni
INFN, sezioni di Bari
V. Ableev, U. Gastaldi, M. Lollo, M. Rigato, P. Temnikov
INFN-LNL, Legnaro
F. Abrosino, G. Chiefari, M. Napolitano, V. Palladino, L. Roscilli, G. Saracino
Universita e sezioni INFN, Napoli
M. Apollonio, P. Chimenti, G. Giannini
Universita e sezione INFN, Trieste
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Edda Gschwendtner
TPG project
mechanics
GEM
TPC
Modifications
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Electronics
Preamps
 FADCs
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HARP TPC
Software
Software
electronics
hexaboard
Newly fabricated
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GEMs
Hexaboard
Mechanics
Edda Gschwendtner
TPC
The test-bed: available
infrastructure from the
HARP experiment
 Beam area
 Solenoid
 Field-cage
 Gas
 Electronics
 DAQ
2.2m long solenoid, 0.7T
field.
 <1% disuniformity over
1.5m
80cm diameter field-cage,
1.5m long
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Edda Gschwendtner
Modifications from HARP TPC to MICE TPC
• removal of the inner field cage
• installation of an adapter flange
for hosting the TPG head
• modified end-plate with holders
of X-ray sources
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Edda Gschwendtner
In the end, the test should provide simultaneously
1. Many longitudinal tracks (as in MICE)
2. With Kr in the gas, a flow of low energy photons
3. With calibration sources in the end-plates a first example of
the calibration system for MICE and flows of photons of
various energies (from few KeV to MeV)
Altogether a demonstration very near the MICE conditions.
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Edda Gschwendtner
GEMs
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6 GEM foils
6 support rings
Assembly and certifying procedure:
HV tests both on raw GEMs and supports
 Glue 1 GEM to 1 support
 HV test on glued GEMs
 Solder resistors
 HV test again
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Edda Gschwendtner
GEMs and supports
3 circular GEM supports, with spacers and
space provided for resistor chains
GEM being stretched before gluing
on support. Following previous
experiences (i.e. COMPASS), the
GEMs are divided in 8 sectors,
powered independently.
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Edda Gschwendtner
GEM HV test
Newly
designed
probe
holder
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Edda Gschwendtner
GEM glued on support
GEM
completed
with
support
and
resistors
for the
voltage
divider
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Edda Gschwendtner
Hexaboard
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First hexaboard is finished.
Delivered on time but unusable for full test.
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The hexaboard has been characterized with measurements of
strip capacitance
Maybe usable for minor measurements, to be verified within
a few days.
3 hexaboards are ordered
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Damaged at last production step (pressing/gluing)
One will possibly be finished for test-beam measurements now!
Edda Gschwendtner
Hexaboard: active surface
Layer N
36
1
1
36
Connector
36
Layer O
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1
Layer M
Edda Gschwendtner
Hexapads & strips
•Active surface of a prototype
hexaboard
300 mm
3 layers of strips
running under the pads
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Edda Gschwendtner
Hexaboard back (connectors) side
•
Mechanical support
structure
•
Prototype hexaboard glued
to a support and seen from
the connectors side.
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Edda Gschwendtner
1st Hexaboard prototype characterization
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Capacitance between neighbouring strips are measured for
the 3 layers.
Typically good values are in the 10pF range.
A short-circuit was verified with an ohmmeter…
Layer M
for shorcut: C==0
90
n:n+1
connector
80
70
60
C [pF]
50
40
Extended areas in short and
some strips with capacitance
higher than normal, but overall
shape of the plot is right 
connections inside the Hexa are
not just random
30
20
10
0
0
100
200
300
400
500
600
-10
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strip number
Edda Gschwendtner
TPG head assembly and location of cables
Design of the complete assembly of the TPG
head, with
• HV guard ring: field-defining ring to be
matched to the corresponding strip on the fieldcage
• 3 GEM supports
• Hexaboard and its support
• Main flange with feeds for HV and gas
Study of signal routing from the
hexaboard to the preamplifier boards via
flat cables. Similar to final MICE setup
(RF shielding is here missing, not
necessary for test beam).
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Edda Gschwendtner
Electronics
16 strips
flexi-cables
Pico-coax bundle
16 strips
2 x 24 channels
to FADC
16 strips
Pico-coax bundle
48 channels
preamp board
Actions:
 Inverted polarity at FADCs: hardware
modification, simple but lengthy
 Measure gain curves for preamplifiers
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Edda Gschwendtner
Software
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DAQ
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HARP, done
Reconstruction
geometry and unpacking
 Modify clustering
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Pattern Recognition & Fit
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First in planes
Then in pads
Use same software as for HARP
Edda Gschwendtner
Plans: first stage
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All components are ready.
NOW detector is being assembled.
Test of TPG head in small volume
 Assemble hexaboard, 3 GEMs
 Gas-piping... Ar/CO2 80/20
 Assemble TPG head and close with 5cm field-cage
 Instrument detector
 X-ray measurements
 Possibly tracks, but no magnetic field.
TPG head can be tested without waiting 2 days for gas
flushing or purging in the big field cage
Good test already for many parameters relevant to MICE
Edda Gschwendtner
Plans: second stage
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Mount into HARP TPC only after TPG head
fully commissioned
First gas: Ar/CH4 91/9
 Present time window for measurements with
magnetic field (X-rays, cosmics, parasitic beam), is
until 15.11
 Longer period maybe possible, to be seen with PS
coordination
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Winter shutdown of the CERN accelerator
complex lasts till next spring.
Resuming operation in April.
 Complete characterization of the detector.
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Edda Gschwendtner