Transcript Slides - indico in2p3

GEM , Resistive M-Bulk , ThGEM detector production.
Rui De Oliveira, Cosimo Cantini, Antonio Teixeira, Olivier Pizzirusso, Julien Burnens
Annecy 26/04/2012
26/04/12
Rui De Oliveira
1
CERN PCB Workshop
18 persons
Building :1000 sqr meters
Making PCBs since 1960
-PCB
-Rigid
-Flex
-Flex-rigid
-Micovias
-fine line (15um)
-large size (up to 2m)
-Thick film Hybrids
-Thin film Hybrids
Activities
PCB
MPGD
C-milling
-Chemical milling
-Cu, Fe, Al, Au, Ag, W, Mb, Ti, Cr, Ni
Low-mass
-MPGD
embedded
-GEM/thinGEM/THGEM/RETHGEM
-MSHP/Cobra
-MICROMEGA/ Bulk/ Micro-BULK
-RES BULK
-Resistive MSGC
-Low mass circuits
-Multilayer flexes with aluminum strips
-embedded heat sinks (carbon, graphite,
metals, diamon)
-Embedded components
-passive
-Active
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Rui De Oliveira
2
OUTLINE
•GEM
•Large size situation
•Detector without spacers
•Micromegas
•Large size situation
•X/Y and U/V/W readout
•Thick GEM
•Large size situation
•Protection
26/04/12
Rui De Oliveira
3
GEM Foil
Present size 1.2m x 0.6m
Future max size 2m x 0.6m
Std pattern 140um pitch/70um holes
26/04/12
Rui De Oliveira
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GEM double mask Vs GEM single Mask
•Base material : Polyimide 50um + 5um on both sides
•Polyimide : Apical NP from company Kaneka (Japan)
•Supplier of the copper clad material : Nippon Mining (Japan)
•Double mask
•Single mask
•Same base material
•Hole patterning in Cu
•Polyimide etch
•Bottom electro etch
•Second Polyimide Etch
•Limited to 40cm x 40cm due to
•Mask precision and
alignment
26/04/12
•Limited to 2m x 60cm due to
•Base material
•Equipment
Rui De Oliveira
5
GEM Double mask Vs GEM
single Mask
•Similar patterns , similar behavior, same material.
•Angles can be adjusted in both structure (Typ value : 70um copper hole , 50um polyimide hole)
Steeper angles gives lower gain but also lower charging up
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Rui De Oliveira
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GEM double mask examples
COMPASS (CERN)
TOTEM (CERN)
LHCb-Muon trigger (CERN)
Support Front-End
Pad Plane SupportCooling
Window
GEM stack
& LV- Distribution
Electronic
&
Shielding Cover
Drift electrode
Media-Distribution
&
Read-out Plane
STAR experiment (US)
26/04/12
•Present double mask
production quantities :
around 500 GEMs/ year in
average
•Max size: 40cm x 40cm
Rui De Oliveira
7
GEM Single mask examples
•CMS RPC possible upgrade
•GEM 1.1m x 500mm
•KLOE – Cylindrical 3 GEM Detector
•GEM 800mm x 500mm
•Read-out 2D : 800mmx 500mm
•Present production rate : 100 Gem /year (1.2mx0.6m)
•Expected rate for 2012 : 250 GEM/Year/technician
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Rui De Oliveira
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•GEM
•Large size situation
•Detector without spacers
•Micromegas
•Large size situation
•X/Y and U/V/W readout
•Thick GEM
•Large size situation
•Protection
26/04/12
Rui De Oliveira
9
No spacer No stretching structure: NS2
10 to 15mm
Readout connector
O-ring
GND
Free to slide
GND
External screws to adjust
stretching
26/04/12
Drift electrode
gluing
Rui De Oliveira
GEM attaching structure
(4 pieces defining gaps)
10
GEM
FRAME
CLOSED
DETECTOR
30 x 30 cm
DRIFT BOARD
26/04/12
1m x 0.5m under production
Rui De Oliveira
Screws
O-ring
HV BNC Connector
Gas connectors
Read-out connectors
HV DIVIDER
11
New GEM stretching method (NS2) advantages:
•No spacers in active area
•Assembly time
• ½ hour for 10cm x 10cm detector (1 technician)
•2 hours for 1m x 0.6m detector (1 technician)
•No gluing , no soldering
•Re opening possible
•GEM exchange possible
•Full detector Re-cleaning possible
• No intermediate test
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Rui De Oliveira
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•GEM
•Large size situation
•Detector without spacers
•Micromegas
•Large size situation
•X/Y and U/V/W readout
•Thick GEM
•Large size situation
•Protection
26/04/12
Rui De Oliveira
13
Large Micromegas
BULK Technology
DUPONT PC 1025 coverlay
BOPP Meshes
SERITEC stretching
Largest size produced:
1.5m x 0.6m
Limited by equipment
PCB
lamination
Mesh deposit
lamination
development
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Rui De Oliveira
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•
•
•
Pad read-out large TPC
Neutrino detector
10 sqr meter in service
T2K experiment
Japan
26/04/12
•
•
Fine segmentation 1cm²,
thickness 8mm for ILC
Hadronic calorimetry
Tested in the RD51 1 kHz
beam
Bulk Micromegas ILC DHCAL first m2
LAPP Annecy
Rui De Oliveira
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15
Atlas CSC replacement project
MPGD Vs Wire chambers
-Faster
-no need for fancy gases
-lower cost
-robust
26/04/12
1.2m x 0.6m
Rui De Oliveira
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Resistive Bulk MicroMegas structure
26/04/12
Rui De Oliveira
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Resistive strip process
PCB
Read-out strips or pads
PCB
Copper lamination layer
PCB
PCB
PCB
Resistive inverse patterning
Resistive layer deposition
Copper stripping
-Good resistor uniformity
-Easy to clean
-Thermally robust
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Rui De Oliveira
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Atlas CSC replacement project
Double sided Board
Resistive strip deposit
Closing
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Bulking
Test before closing
Rui De Oliveira
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Situation and on going productions
• Situation on large STD BULK
– Up to 5 detectors (1.5m x 0.6m max) produced all good
• Situation on large resistive detector production
– 4 CSC type (1.2m x 0.6m) 1D produced 1 good
• Physical parameters OK , leakage current out of tolerance
– 4 MSW type (1.2m x 0.6m) 2D produced 1 good
• Physical parameters OK , leakage current out of tolerance
– Yield 25% due to dust contamination (solution found recently)
– Ionic contamination and pillar shape are not the cause of leakage
currents
• Next production with corrections
– 1 detector 1 m x 1m end of June
26/04/12
Rui De Oliveira
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•GEM
•Large size situation
•Detector without spacers
•Compact HV divider
•Micromegas
•Large size situation
•X/Y and U/V/W readout
•Thick GEM
•Large size situation
•Protection
26/04/12
Rui De Oliveira
21
Bulk MicroMegas resistive anode and 2D readout
We have produced :
X/Y read-out
U/V/W read-out
Grounded mesh detectors
Resistive strips
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Rui De Oliveira
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X/Y read-out
26/04/12
U/V/W read-out
Rui De Oliveira
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•GEM
•Large size situation
•Detector without spacers
•Compact HV divider
•Micromegas
•Large size situation
•X/Y and U/V/W readout
•Thick GEM
•Large size situation
•Protection
26/04/12
Rui De Oliveira
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THGEM and read-out for Double phase pure argon
LEM-TPC with 2D anode
THGEM description:
-800mm x 400mm Halogen Free
-1mm & 2mm thick
-RIM 40um (differential etching)
-0.8mm pitch
-0.5mm hole diameter
@ ELTOS:
-Drilling
-Photolithography
-Differential etching
@ CERN:
-Thermal treatment
-Passivation
-Cleaning
-Electrical Test
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Rui De Oliveira
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•GEM
•Large size situation
•Detector without spacers
•Compact HV divider
•Micromegas
•Large size situation
•X/Y and U/V/W readout
•Thick GEM
•Large size situation
•Protection
26/04/12
Rui De Oliveira
26
THGEM: limitations
Strong ionizing particles produce sparks.
Sparks damage the electrodes and are responsible of a low degradation of the gain.
The active element then drains steadily a DC current from the power supply.
Ideas to cancel the phenomenum :
-increase the number of TH GEM (we want to avoid)
- Reduce the capacity by segmenting the THGEM
- Decouple sectors with resistors
- Resistive electrodes
- Change metal
- Rim , no rim
-Change dielectrics
After long sparking period they all failed but some structures are 1000 time better than others
We went back to theory to understand the problem
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Rui De Oliveira
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Voltage-Current Characteristic of the DC Electrical Discharges
C :negligible
triggered
Self maintained
Corona
avalanche
Breakdown
Glow discharge
Spark
- Gas Discharge Physics, Yuri P. Raizer
26/04/12
Rui De Oliveira
- DC pulse-powered
micro-discharges on planar
electrodes, Yogesh B. Gianchandani
28
I
V
V: supply voltage (2KV)
R: limiting resistor (1Mohms)
C: THGEM capacity (1nF)
R’: spark local surface resistor (10 Ohms)
: spark
I : charge current
I’: discharge current inside capacitor
C
Vc
I’
Charge  T = RC (1us)I max =V/R= 2mA (limited to 10uA)
Spark discharge T = R’C (10ns) I’ max = (200 A)
That’s consistent with measurements
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Rui De Oliveira
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R’ increase
Due to spark damage ex:1 MOhms
R’ is low
Clean metal ex: 10 Ohms
End working point
R’ value > R
DC current
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Rui De Oliveira
Initial Working point
R’ low value
Repetitive sparks
30
?
High energy Sparks
Low energy sparks?
Glow discharge
Perfect Hole ?
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Rui De Oliveira
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Thank you
Questions?
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Rui De Oliveira
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