construction and Test of the Cylindrical-GEM detectors for the KLOE-2 Inner Tracker

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)


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


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


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


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


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


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


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


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


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…


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


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


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


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


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


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


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


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


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


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


KLOE2-

ITLayer 1 Cosmics

VCI 2013 – 12/02/2013

Cosmics hits are reconstructed by

requiring a track in the 3 planar GEMs


KLOE2-

ITLayer 2 Cosmics

VCI 2013 – 12/02/2013

Z vs X (Lego View)

noise

cosmic

tracks


KLOE2-

ITLayer 3 Cosmics

VCI 2013 – 12/02/2013


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


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


KLOE2-

IT

SPARES

VCI 2013 – 12/02/2013


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


KLOE2-

ITClosing of the Last Layer

VCI 2013 – 12/02/2013


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


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


KLOE2-

ITIT Layers

VCI 2013 – 12/02/2013

construction and Test of the Cylindrical-GEM detectors for the KLOE-2 Inner Tracker

Documents

Transcript of construction and Test of the Cylindrical-GEM detectors for the KLOE-2 Inner Tracker