status of kloe-2 inner tracker
DESCRIPTION
Status of KLOE-2 Inner Tracker . JOINT-GEM meeting Helsinki 15 July 2010 G.Bencivenni. The Inner Tracker group. G. De Robertis , N. Lacalamita , R. Liuzzi , F. Loddo , M. Mongelli , A. Ranieri , V. Valentino INFN Bari, Bari, Italy G. Morello , M. Schioppa - PowerPoint PPT PresentationTRANSCRIPT
Status of KLOE-2 Inner Tracker
JOINT-GEM meeting
Helsinki
15 July 2010
G.Bencivenni
The Inner Tracker group
G. De Robertis, N. Lacalamita, R. Liuzzi, F. Loddo, M. Mongelli, A. Ranieri, V. Valentino
INFN Bari, Bari, Italy
G. Morello, M. Schioppa INFN Cosenza, gruppo collegato LNF, Cosenza, Italy
A. Balla, G. Bencivenni, S. Cerioni, P. Ciambrone, E. De Lucia,D. Domenici, J.Dong, G. Felici, M. Gatta, M. Jacewicz, S. Lauciani,
V. Patera, M. Pistilli, L. Quintieri, E. Tshadadze Laboratori Nazionali di Frascati - INFN, Frascati, Italy
A. Di Domenico, M. Capodiferro, A. Pelosi INFN Roma, Roma, Italy
Inner Tracker Project
still a factor 2.5÷3 improvement on KS → vertex resolution
• 4 tracking layers with radii from 13 to 23cm (1 layer removed for a safe insertion)• 700 mm active length • XV strips-pads readout (40o stereo angle)
• 1.5% X0 total radiation length in the active region with Carbon Fiber supports
3 mm
2 mm2 mm
2 mm
Cathode
GEM 1GEM 2
GEM 3
Anode
Read-out
Cylindrical Triple GEMCylindrical GEM technology
Cylindrical GEM technology
# layersdx@vtx (mm)
dz@vtx(mm)
5 1.6 1.1
4 1.7 1.18
NO IT 4.2 3.1
R&D step by step
1. 2008. C-GEM prototype using 3 (354x330 mm2) GEM foils spliced together with simplified readout. No final readout. No final GEM
2. 2009. 100x100 mm2 planar chambers with XV readout pattern for study in magnetic field. Final readout. No final GEM
3. 2010. Two large (300x700 mm2) planar chambers with the new single-mask GEM foils and XV readout. Final readout and final GEM
Cylindrical-GEM prototype
352 mm
960 mm
Ø=300mm, L=350mmØ=300mm, L=350mm1538 1538 axial stripsaxial strips 650 650
µm pitchµm pitch
Very light detector: no frames in the
active area
Very light detector: no frames in the
active area
3 spliced foils vacuum bag
GASTONE: the IT FEE chip
• Mixed analog-digital circuit• Low input equivalent noise, low power consumption and high integrated chip;• 4 blocks:
Sensitivity (pF) 20 mV/fC
ZIN 400 Ω (low frequency)
CDET 1 – 50 pF
Peaking time 90 – 200 ns (1-50 pF)
Noise (erms) 800 e- + 40 e-/pF
Channels/chip 64*
Readout LVDS/Serial
Power consum. ≈ 0.6 mA/ch
GASTONE 64 chGASTONE 64 ch
0.35 CMOS - no Radhard0.35 CMOS - no Radhard
charge sensitive preamplifier shaper leading-edge discriminator (prog. thr.) monostable (stretch digital signal for trigger)
C-GEM prototype: test beam
Spatial Resolution (GEM) =(250µm)2 – (140µm)2 200µm
Gas: Ar/CO2 = 70/30Gain: ~2·104
FEE: 16-channels GASTONETracking: 2x8-MDT stations
10 GeV pion beamCERN-PS T9 area
MDTs MDTs
Efficiency ε = 99.6%
XV readout stuides
40° X
pitch 650 µm
V
pitc
h
650
µm
10x10 cm2 planar GEM for readout study in magnetic fieldReadout is a multilayer kapton circuit with XV pattern of copper strips and pads: • X-view will provide r-φ coordinate in CGEM• V-view made of pads connected by internal vias and with ~40°stereo angle• XV crossing will provide z coordinate in CGEM
Garfield simulatio
n of B field
XV
Test beam in magnetic field
Gas: Ar/CO2 = 70/30Gain: ~2·104
FEE: GEMs partially equipped with 22 GASTONE boards
Trigger: 6 scintillators with SiPM (3 upstream, 3 downstream)
External Trackers: 4 planar GEMs w/650 µm pitch XY strips
• H4 beam-line at CERN-SPS: 150 GeV pions• Goliath Magnet: dipole field up to 1.5T in a ~3x3x1m3
• Semi-permanent setup for RD51 users
BEAM
X-Y GEMs
X-V GEM
dipole magnet
Testbeam in magnetic field
KLOE B - field
CGEM r-φ resolution(bending plane)
x = 200 m
working pointIncrease of B field requires a higher
gain
Increase of B field requires a higher
gain
CGEM z resolution
Large area GEM
Very large GEM: 0.21 m2
Very large GEM: 0.21 m2
• GEM foils up to 350x700 mm2 are needed for the IT (3 are spliced together for 1 electrode)
• After a change in the GEM manufacturing technique and >1 year R&D by CERN TS/DEM we received the first large GEM foils in April
• Two planar prototypes built with the final dimensions of IT foil for pre-production test
hole section
Large planar prototype300mm
700m
mGEM are stretched on a custom-made machine with a tension of ~1kg/cm measured by load-cells
FR4 frame is glued on the GEM with a vacuum-bag.The result is a planar foil (20 µm sag) with no need of frames inside the active area.
XV readout• The prototype has been assembled with the final KLOE-2 readout: XV strips with 650 μm pitch (~220k vias)• It will be equipped with GASTONE-64 and tested CERN-T9 in october 2010
first GEM framed and placed on
the readoutXV
Final assembly
Closing of the chamber
A heavy Al plate is placed to distribute the
pressurefinal gluing w/gas vacuum
Preliminary tests
The detector has been flushed with Ar/CO2 (70/30) and tested in current-mode with a 137Cs source (660 keV photons). Cosmic ray test is starting soon.
137Cs gamma source cosmic ray
Optimization of the fields
Only slight difference
between the two GEM (due to different hole
shapes?)
Only slight difference
between the two GEM (due to different hole
shapes?)Final operating fields values:1.0 – 3.0 – 3.5 – 6.5 kV/cm(Drift – Transf1 – Transf2 –
Induction)
Equal charge sharing occurs at higher induction field in the single-mask
4.8 6.5
Gain measurement• The different shape of the hole affects the gain of the GEM
• Gain ~25% lower in single-mask GEM• Only ~20 V increase in the operating voltage of a Triple-GEM to reach
same gain• NO discharge observed up to 40000 gain
Very stable operationVery stable operation
Inner Tracker project
Technical Design Report of the Inner
Tracker for the KLOE-2 experiment
[arXiv:1002.2572]
Technical Design Report of the Inner
Tracker for the KLOE-2 experiment
[arXiv:1002.2572]
KLOE-2 beam pipe with the IT
IT sketch
CF load test
Time ScheduleTooling and Components
• Cylindrical moulds to make electrodes: end of June (L1) – end of July (L2)• Detector mechanics (fiberglass rings): mid of july• Quality control system (microscope + HV test box): nearly ready• GEM foils: G1 (23 July), G2,G3 (20 Aug) • Readout anode circuits: 20 Aug• Vertical assembling machine (mechanics + electronics): mid of September
Production
• July: test of G1 foils and production of a fake layer (w/mylar)• end Aug: test of G2,G3, connector soldering on anode foils• September: start of Layer1 construction• October: Integration and test of vertical assembling machine• November: Layer1 assembling• December: Layer1 test
Conclusion• The Cylindrical-GEM Inner Tracker project has been finalized
• In the last 3 years an extensive R&D program has been accomplished
• full-scale Cylindrical-GEM prototype successfully tested• XV readout designed and characterized in magnetic field• new single-mask GEM tested
• Two planar prototypes with 300x700 mm2 foils (same dimensions for the cylindrical Inner Tracker) have been built
• current mode test showed good stability, uniformity and gain• cosmic ray test with final FEE and DAQ under preparation (oct. 2010)
• The first two Layers of the IT have been funded : • L2 completed by the end Nov. • then L1 production without dead time
Large Area: Gain Uniformity
15500
15600
15800
16300
15700
15700
15000
15200
15500
15000
14800
14800
12 positions scanned with gamma source (~100 mm2 spot)
Maximum difference (~1000) is of the same order of magnitude of the estimated single error (~800)
Further test needed with more collimated source