Post on 17-Jan-2016
description
CONSTRUCTION AND TEST OF THE CYLINDRICAL-GEM
DETECTORS FOR THE KLOE-2 INNER TRACKER
Danilo DomeniciOn behalf of the KLOE-2 IT subgroup
Vienna Conference on Instrumentation 2013
D. Domenici – INFN-LNF2
KLOE2-
ITThe KLOE Detector at
Dafne
VCI 2013 – 12/02/2013
Drift Chamber (He/iC4H10 light gas mixture) EM Calorimeter (Pb/SciFi, excellent time resolution) 0.52 T Magnetic Field (Superconductive coil) Dafne factory (e+e- at 1020 MeV and Lint=10fb-1/y)
D. Domenici – INFN-LNF3
KLOE2-
ITKLOE-2 Upgraded
VCI 2013 – 12/02/2013
LET
QCAL
InnerTracker
3 new detectors will be inserted before summer: Photon taggers (HET/LET for γγ interactions) Low angle Calorimeters (CCAL/QCAL to improve solid angle
coverage) Inner Tracker (to improve vertex resulution)
resolution on KS ππ vertex from cS to cS/3
D. Domenici – INFN-LNF4
KLOE2-
ITCylindrical-GEM Inner
Tracker
VCI 2013 – 12/02/2013
4 layers at 13/15.5/18/20.5 cm from IP and 700 mm active length
rφ 250 µm and z 400 µm in 0.42 T magnetic field XV strips-pads readout (20o÷30o stereo angle) 2% X0 total radiation length in the active region
3 mm
2 mm2 mm
2 mm
Cathode
GEM 1GEM 2
GEM 3
Anode
Read-out
Cylindrical Triple GEMFEE
boards
D. Domenici – INFN-LNF5
KLOE2-
ITLayout of the GEM foil
VCI 2013 – 12/02/2013
700 mm
300 ÷ 430 mm
First batch ever produced with a single-mask etching technique developed by CERN-TE-MPE-EM and RD51 to produce large area foils
The top side of the active area is divided in 40 sectors
The HV connections are grouped in 4 tails that are directly connectorized
Each sector can be set to down voltage, ground or float by an external jumper
pinholes
gas holes
D. Domenici – INFN-LNF6
KLOE2-
ITGEM foils Quality Test
VCI 2013 – 12/02/2013
few sectors with current > 1 nA @600
V
GEM is tested in a N2 flushed plexiglass boxto reduce RH below
10%
Each Sector must draw a current < 1nA @
600V
Discharge rate is measured over a
period of ~1h
Discharge rate @600 V
D. Domenici – INFN-LNF7
KLOE2-
ITManufacturing a C-GEM
VCI 2013 – 12/02/2013
Epoxy glue is distributed by hand on a 2 mm wide
line
3 GEM foils are spliced together with a 3 mm overlap and closed in a vacuum bag (0.9 bar)
Alignement pinholes
Vacuum holes
Alignement pinholes
Vacuum holes
D. Domenici – INFN-LNF8
KLOE2-
ITManufacturing a C-GEM
VCI 2013 – 12/02/2013Vacuum bag is closed
GEM is protected with a Mylar sheet and wrapped on the cylindrical mold
Transpirant tissue is placed around to distribute vacuum
Final cylindrical GEM with internal and external rings
D. Domenici – INFN-LNF9
KLOE2-
ITManufacturing the
Cathode
VCI 2013 – 12/02/2013
Inner layer is glues on the mold Nomex honeycomb is glued on the cathode
foil
Cathode is rolled on the mold and glued in a vacuum
bag
Final electrode
D. Domenici – INFN-LNF10
KLOE2-
ITThe Readout Electrode
VCI 2013 – 12/02/2013
X strip
V strip
X pitch 650µm X res 190µm (250µm @ B=0.5T)
V pitch 650µm Y res 350µm
Readout plane is realized at CERN TE-MPE-EM as a kapton/copper multilayer flexible circuit.It provides 2-dimensional readout with XV strips on the same plane X are realized as longitudinal strips V are realized by connection of pad
through conductive holes and a common backplane
Pitch is 650 µm for both
D. Domenici – INFN-LNF11
KLOE2-
ITManufacturing the
Readout
VCI 2013 – 12/02/2013
is rolled over the mold
…and closed in a vacuum bag
1k strips1M pads
Readout circuit obtained by splicing 3 foils
…glued…
D. Domenici – INFN-LNF12
KLOE2-
ITReadout CF Lamination
VCI 2013 – 12/02/2013
first 90µm CF skin
5mm HC second 90µm CF skin
curing 24h in autoclave
final readout electrode
Then the circuit is shielded with with a very ligth Carbon fiber composite structure realized by an external company (RiBa Composites, Faenza, IT)
The shield is composed by a sandwich of two 90 µm thick carbon foils prepreg with epoxy spaced by a 5 mm thick Nomex honeycomb
D. Domenici – INFN-LNF13
KLOE2-
ITFixing of the PEEK Spacing Grid
VCI 2013 – 12/02/2013
To avoid possible relaxation of the gaps due e.g. to thermal expansion of the foils, we fix a spacing grid on the GEMs (only for Layers 3 and 4)
It is realized by assembling 8 rings and 12 rods of 300 µm thick PEEK
PEEK grid assembled
grid fixed on the GEM
D. Domenici – INFN-LNF14
KLOE2-
IT
VCI 2013 – 12/02/2013
The GEM is placed on the
Machine with its mold
Everything is aligned with an axial precision of
≈0.1mm/1.5m
The Readout is moved down
around the GEM
Anode
GEM
Assembling a Triple-GEMA Vertical Insertion Machine is used to assemble the 5 electrodes of a
Cylindrical-GEM
D. Domenici – INFN-LNF15
KLOE2-
ITAssembling Details
VCI 2013 – 12/02/2013
Internal GEM surface with the anular FR4 flange
Detector is sealed by an epoxy flow
Insertion machine is rotated to seal both
sides
Final C-GEM detector
D. Domenici – INFN-LNF16
KLOE2-
IT4 IT Layers Completed
VCI 2013 – 12/02/2013
The 3 innermost Layers have been completed and tested with β source and cosmic rays
The Layer4 has been closed last week
At the end of February the 4 layers will be inserted one into another and mounted on the Dafne beam pipe
Layer 1
Layer 2
Layer 3
Layer 4
FEE boards
with Gastone
chip
D. Domenici – INFN-LNF17
KLOE2-
ITIT FEE: Gastone Chip
VCI 2013 – 12/02/2013
Technology 0.35 CMOS - no radhard
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
128 channels GASTONE Board
Mixed analog-digital circuit Low input equivalent noise, low power
consumption and high integrated chip 4 blocks:
1. charge sensitive preamplifier2. shaper3. leading-edge discriminator4. monostable
Visit the Gastone poster by Flavio
Loddo
D. Domenici – INFN-LNF18
KLOE2-
ITTest Setup
VCI 2013 – 12/02/2013
All the detectors have been tested with a cosmic-ray test-stand equipped with an external Tracking System provided by 3 planar GEMs 10x10 cm2
Final signal and HV cables, FEE and DAQ systems have been used in the tests
The test-stand is also equipped with a 90Sr movable source to perform fast measurements without tracking
D. Domenici – INFN-LNF19
KLOE2-
ITSpace Resolution
VCI 2013 – 12/02/2013
Z resolutionr-φ resolution
(bending plane)
KLOE field 0.52 T
Space resolution has been measured as a function of a transverse Magnetic Field to reproduce the KLOE situation
In the bending plane the electrons are spreaded by the field with a consequent increase of space resolution
At the KLOE field of 0.52 T the resolution rφ 250 µm is still within the experiment requirement
The field effect is not visible in the non-bending plane as expected
D. Domenici – INFN-LNF20
KLOE2-
ITBlocking Capacitor on GEM3 Down
VCI 2013 – 12/02/2013
The capacitive coupling between the GEM3 Down and the Readout plane could result in induced currents causing high-multiplicity «splash events»
The effect is strongly suppressed by coupling the GEM3 Down to Ground through a series RC circuit with large capacitance and small resistance
without BC
C = 2.2 nFR = 10 Ω
D. Domenici – INFN-LNF21
KLOE2-
ITLayer 1 Source Scan
VCI 2013 – 12/02/2013
The profile of the source in 6 different positions
is reconstructed by triggering the DAQ with
a clock signal
This fast test allows to check the cabling and the uniformity of the
detector
D. Domenici – INFN-LNF22
KLOE2-
ITLayer 1 Cosmics
VCI 2013 – 12/02/2013
Cosmics hits are reconstructed by
requiring a track in the 3 planar GEMs
D. Domenici – INFN-LNF23
KLOE2-
ITLayer 2 Cosmics
VCI 2013 – 12/02/2013
Z vs X (Lego View)
noise
cosmic
tracks
D. Domenici – INFN-LNF24
KLOE2-
ITLayer 3 Cosmics
VCI 2013 – 12/02/2013
D. Domenici – INFN-LNF25
KLOE2-
ITLayer 3 Cosmics
VCI 2013 – 12/02/2013
D. Domenici – INFN-LNF26
KLOE2-
ITFirst C-GEM Workshop
VCI 2013 – 12/02/2013
Last October in Frascati we organized a Cylindrical GEM Mini-workshop dedicated to this novel technology
Among the participants there were: Rui de Oliveira from CERN workshop where the GEM foils are
produced Qun Ouyang from IHEP Beijing Lev Shekhtman from INP Novosibirsk
A very strong interest have been shown by our chinese and russian collegues to exploit the Cylindrical GEM technology on the future upgrades of the BESIII and VEPP2000 experiments
D. Domenici – INFN-LNF27
KLOE2-
ITConclusions
VCI 2013 – 12/02/2013
We exploited the intrinsic lightness and flexibility of a GEM detector to build a fully cylindrical Inner Tracker without frames in the active area and an X0 ≈ 2%
After more than one year of construction time we have completed the 4 Layers that will be mounted as upgrade of the KLOE detector
The detectors have been extensively tested showing a good operational stability and the expected performance
We are collaborating with other groups that have expessed interest on Cylindrical GEMs in order to improve such technology and expand its operational field
D. Domenici – INFN-LNF28
KLOE2-
IT
SPARES
VCI 2013 – 12/02/2013
D. Domenici – INFN-LNF29
KLOE2-
ITMaterial Budget
VCI 2013 – 12/02/2013
MaterialRadiation
Length (cm)
Copper 1,43Polyimide - Kapton 28,6Carbon fiber 28Argon 14000Isobuthane 17000Epoxy - Araldite 2011 33,5Honeycomb - Nomex 1250Fiberglass - FR4 16Air 30500Aluminum 8Gold 0,33
Thickness (µm)
Radiation Length (%)
Copper 3 1,68E-04Polyimide 50 1,40E-04Copper 3 1,68E-04GEM foil 56 4,76E-04
Copper 3 2,10E-04Polyimide 50 1,75E-04Honeycomb 3000 2,40E-04Polyimide 50 1,75E-04Copper 3 2,10E-04Cathode foil 3106 1,01E-03
Gold 0,1 3,03E-05Copper 5 2,45E-04Polyimide 50 1,75E-04Copper 5 1,05E-04Epoxy 12,5 3,73E-05Polyimide 125 4,37E-04Epoxy 12,5 3,73E-05Polyimide 50 1,75E-04Copper 3 2,10E-04Gold 0,1 3,03E-05Anode Foil 263 1,48E-03
Carbon fiber 90 3,21E-04Honeycomb 5000 2,40E-04Carbon fiber 90 3,21E-04CF Shield 3200 9,54E-04
Total 1 Layer4,93E-
03
Total 4 Layers1,97E-
02
The KLOE-2 requirement of X0 < 2%
is fulfilled
Gas (90% Ar – 10% iC4H10) 9000 6,29E-05
D. Domenici – INFN-LNF30
KLOE2-
ITClosing of the Last Layer
VCI 2013 – 12/02/2013
D. Domenici – INFN-LNF31
KLOE2-
ITGain and Discharges
VCI 2013 – 12/02/2013
Gas gain measurement performed in current mode using as normalization a refernce detector with known gain
Discharge measurement performed with a 141Am α source KLOE2 chosen mixture Ar/Isobuthane (90/10) is compared
with the standard gas mixture Ar/Co2 (70/30) Our working gain will be 2 x 104
D. Domenici – INFN-LNF32
KLOE2-
ITReadout Quality Control
VCI 2013 – 12/02/2013
V Strip#
Shorts
Made by a 100 ps precision Time Domain Reflectometer
Transmission line length and its damages evaluated by measuring the delay of the reflected signal
D. Domenici – INFN-LNF33
KLOE2-
ITIT Layers
VCI 2013 – 12/02/2013