Edda Gschwendtner1
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 StenisCERN, Geneva
M.G. Catanesi, E. RadicioniINFN, sezioni di Bari
V. Ableev, U. Gastaldi, M. Lollo, M. Rigato, P. TemnikovINFN-LNL, Legnaro
F. Abrosino, G. Chiefari, M. Napolitano, V. Palladino, L. Roscilli, G. SaracinoUniversita e sezioni INFN, Napoli
M. Apollonio, P. Chimenti, G. GianniniUniversita e sezione INFN, Trieste
Edda Gschwendtner2
TPG project
TPC
GEM
hexaboardelectronics
mechanics
Newly fabricated GEMs Hexaboard Mechanics
Modifications Electronics
Preamps FADCs
HARP TPC Software
Software
Edda Gschwendtner3
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
Edda Gschwendtner4
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
Edda Gschwendtner5
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 photons3. 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.
Edda Gschwendtner6
GEMs
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
Edda Gschwendtner7
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.
Edda Gschwendtner8
GEM HV test
Newly designed probe holder
Edda Gschwendtner9
GEM glued on support
GEM completed with support and resistors for the voltage divider
Edda Gschwendtner10
Hexaboard
First hexaboard is finished. Delivered on time but unusable for full test.
Damaged at last production step (pressing/gluing)
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 One will possibly be finished for test-beam measurements now!
Edda Gschwendtner11
Hexaboard: active surface
Layer M
Layer N
Layer O
Connector
1
1
36 1
36
36
Edda Gschwendtner12
Hexapads & strips•Active surface of a prototype hexaboard
300 m
3 layers of strips running under the pads
Edda Gschwendtner13
Hexaboard back (connectors) side
• Mechanical support structure
• Prototype hexaboard glued to a support and seen from the connectors side.
Edda Gschwendtner14
1st Hexaboard prototype characterization
Layer Mfor shorcut: C==0
-10
0
10
20
30
40
50
60
70
80
90
0 100 200 300 400 500 600
strip number
C [
pF
]
n:n+1
connector
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…
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
Edda Gschwendtner15
TPG head assembly and location of cablesDesign of the complete assembly of the TPG head, with
• HV guard ring: field-defining ring to be matched to the corresponding strip on the field-cage
• 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).
Edda Gschwendtner16
Electronics
16 strips
16 strips
16 strips
flexi-cables
48 channelspreamp board
Pico-coax bundle
2 x 24 channels to FADCPico-coax bundle
Actions: Inverted polarity at FADCs: hardware
modification, simple but lengthy Measure gain curves for preamplifiers
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Software
DAQ HARP, done
Reconstruction geometry and unpacking Modify clustering
First in planes Then in pads
Pattern Recognition & Fit Use same software as for HARP
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Plans: first stage
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 Gschwendtner19
Plans: second stage 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
Winter shutdown of the CERN accelerator complex lasts till next spring. Resuming operation in April. Complete characterization of the detector.