Transcript (drift) Chamber

GridPix
Een Detector R & D project voor:
- Large TPC for ILC
- GOSSIP & the ATLAS SCT Upgrade
Harry van der Graaf
NIKHEF, Amsterdam
Electronische Afdeling,
Nikhef April 4, 2007
Time Projection Chamber (TPC): 2D/3D Drift Chamber
The Ultimate Wire (drift) Chamber
track of
charged
particle
E-field
(and B-field)
Wire plane
Wire Plane
+
Readout Pads
Pad plane
Problem
With wires: measure charge distribution over cathode pads:
c.o.g. is a good measure for track position;
With GEMs or Micromegas: narrow charge distribution
(only electron movement)
avalanche
wire
GEM
Micromegas
Cathode pads
Solutions:
- cover pads with resisitive layer
- ‘Chevron’ pads
- many small pads: pixels!
The MediPix2 pixel CMOS chip
- 256 x 256 pixels
- pixel pitch: 55 x 55 μm2
- Within each pixel:
- preamp + shaper + discr
- 14-bits counter
- discr. thresholds
- Developed by MediPix
Consortium, CERN
We apply the ‘naked’ MediPix2 chip
without X-ray convertor!
MediPix2 & Micromegas
55Fe
Cathode (drift) plane
Micromegas
Drift space: 15 mm
Baseplate
MediPix2 pixel sensor
Brass spacer block
Printed circuit board
Aluminum base plate
Very strong E-field above (CMOS) MediPix!
He/Isobutane
80/20
Modified MediPix
δ-ray!
Efficiency for
detecting single
electrons:
< 95 %
Integrate GEM/Micromegas and pixel sensor:
InGrid
‘GEM’
‘Micromegas’
By ‘wafer post processing’
InGrid VS Micromegas
Micromegas
Electroforming tech.
– Large areas
– Large pillar Ø (250 µm)
– Hybrid detector
Manual mounting
InGrid
Micro-electronic tech.
– Wafer scale areas
– Minimum pillar Ø (30 µm)
– Integrated detector
Compact / Mass producible
– All geometric parameters
accurately controlled
Gap, Holes, Supporting structures
Processing InGrids
Strips Litho.
50 µm SU8
UV Exposure
0.8 µm Al
Holes Litho.
Suspended
membrane 50 µm
above the wafer
Development
Prototypes
Hex / Pillars
19 different fields of 15 mm Ø
2 bonding pads / fields
Square / Walls
Square / Pillars
Square / Pillars
Experimental Setup
55Fe
collimated
source
Gas sealed
chamber
Grid to HV
Cathode to HV
Anode to ground
Connectors to 10 MΩ
resistors in series with
electrodes
Energy resolution in Argon IsoC4H10 80/20
• Observation of two lines:
Kα @ 5.9 keV
Kβ @ 6.4 keV
• FWHM of the Kα distribution
16.7 %
• Gain fluctuations
< 5%
Very good energy resolution:
Very precise dimensions d < 0.1 μm
Other applications of GridPix:
- μ-TPC
- Transition Radiation Detectors
- GOSSIP: tracker for intense radiation environment
The ATLAS Detector
ATLAS Semiconductor Tracker (SCT)
Inner Tracker: record all tracks
of charged particles
For instance: lifetime measurement
Heavy quark mesons….
D*  D  slow
D   K  K  
Lifetime measured from secondary vertex
ct ~ 100 micron
Take Lorentz boost into account
E
γ
m
ALEPH event display
Vertexing
High spatial resolution
low mass
low power
fast
 Semiconductor pixel detector
Vertex determination
Few points
accuracy O(0.001-0.01 mm)
Semiconductor (pixel, strip)
detectors
Depleted Si, 300 μm
Vbias = 150 V
electron-hole
pairs
(pixel) chip with
preamps, shapers,
discriminators
ATLAS pixel: basic element
Wire-bonding FE’s Wire-bonding MCC MC
Flex Hybrid
C
bumps
sensor
FE
chip
FE chip
C-C support
Flex module 2.x
Side view
not to scale
The ATLAS Vertex Pixel Detector
~2.0 m2 of sensitive
area with 0.8  108
channels
Three
disk
layers
Three barrel layers
50 m  400 m
silicon pixels (50 m
 300 m in the Blayer)
Barrel SCT unit
EndCap SCT unit
barrel SCT
Two of the SCT barrel
support structures
Barrel and EndCap SCT
X-ray quanta
e-
π-
Transition Radiation Tracker
Si (vertex) track detector
GOSSIP
Cathode (drift) plane
Cluster1
Si depletion layer
Vbias
Cluster2
Integrated Grid (InGrid)
CMOS chip
1mm,
100V
Cluster3
50um,
400V
Slimmed Silicon Readout chip
Input pixel
50um
• Si strip detectors
• Si pixel detectors
• MAPs
Gas: 1 mm as detection medium
99 % chance to have at least 1 e-
Gas amplification ~ 1000:
Single electron sensitive
All signals arrive within 16 ns
MIP
MIP
InGrid
Cathode foil
CMOS chip
‘slimmed’ to 30 μm
CMOS pixel array
Drift gap: 1 mm
Max drift time: 16 ns
GOSSIP: Gas On Slimmed SIlicon Pixels
Gas instead of Si
Pro:
-
no radiation damage in sensor: gas is exchanged
modest pixel (analog) input circuitry: low power, little space
no bias current: simple input circuit
CMOS pixel chip main task: data storage & communication (rad hard)
low detector material budget: 0.06 % radiation length/layer
typical: Si foil. New mechanical concepts:
self-supporting pressurized co-centric balloons; ‘laundry line’
low power dissipation : little FE power (2 μW/pixel); no bias dissipation
operates at room temperature (but other temperatures are OK)
less sensitive for neutron and X-ray background
3D track info per layer if drift time is measured
Con:
-
Gaseous chamber: discharges (sparks): destroy CMOS chip
gas-filled proportional chamber: ‘chamber ageing’
Needs gas flow
Parallax error: 1 ns drift time measurement may be required
Discharges
Vonken
CMOS Chip protection against
- discharges
- sparks
- HV breakdowns
- too large signals
Silicon Protection: SiProt
Amorph Si (segmented)
Emperical method:
Try RPC technology
MediPix+SiProt+InGrid
Levensduur: 12 h
He/Isobutane
Met 3 μm SiProt:
- ‘Directe’ schade door heet plasma: afwezig
- te groot ladingssignaal voor pixel electronica

- Dikkere SiProt laag (20, 30 , 40, 50 μm ! )
- Protectie circuit in pixel
- SiProt aan onderkant van InGrid
!!Als dikkere SiProt niet werkt:
- MPW test (Gossipo-3)
- 600 kE nodig voor nieuwe full-scale pixel chip!!
A-Si not adequate? Then TwinGrid
Irradiation with 8 keV X-rays:
No rate effects up to anode current
density of 0.2 μA / mm2
 very fast track counting possible!
After 0.3 Coulomb/mm2:
 (eq. 3.7 x 1016 MIPs/cm2 !!)
Ageing
deposit of carbon polymer on anode
is clearly visible. Micromegas is
clean (!?)
Little deposit on cathode, and……
Chamber still worked!
Nieuwe Pixel Chips voor GridPix/Gossip
GOSSIPO-1:
- test of preamp-shaper-discriminator for GOSSIP
- ‘MultiProjectWafer’ in 0.13 μm technology
GOSSIPO chip
Submitted December 2005.
Input pad
LM
Ground planeM6
Ground
Cpar = 10fF…50fF
M3
Output
M2
Cfb=1fF
M1
Substrate
Parasitic metal-to-metal
fringe capacitances.
Coaxial-like layout of the inputfeedback interconnection.
Very low (parasitic) capacitance
at the input (Cpar → 10 fF) .
GOSSIPO (RO-FE) chip design
-
match extreme small source capacity: 10 fF
peaking time: 40 ns
noise (expected: 60 e- input eq.)
power: 2 μW/pixel (!)
Triple Well technology: separation of analog and digital ground
100 MHz clock close to analog circuit
- Threshold setting (6 x 60 e-) fine!
- Effect of digital switching on pixel
analog signal negligible
Vthreshold = 350 ediscriminator output
Maart – Juni 2006: Gossip-DAQ werkgroep
GOSSIPO-2
test of
preamp-shaper-discriminator
and
700 MHz TDC per pixel
• 0.13 μm technology
• containing 16 x 16 pixels
• Submission Nov 29, 2006
• Can be used for GOSSIP demo!
3 x 2 mm2
Proposed FE architecture for data communication
pixel
start 700 MHz
avalanche
input pad
oscillator
AmpShaDisc
BX clock
stop
40 MHz
BXcounter
memory 1
BX-ID +Tdrift +Ttime-over-threshold
16 bits
memory 2
BX-ID +Tdrift +Ttime-over-threshold
16 bits
DAQ
bus
valid BX
pixel-ID + Tdrift + TtimeOverthreshold
New mechanical concept
(virtual) target: pixel B-layer @ SLHC
1. Inventarisation of all services to detector units
2. Integration of services, detectors and support mechanics
services:
-
cooling
power
data communication
gas
New mechanics + cooling concepts for Gossip
- As little as possible material
- detector consists of foil!
- less power required ( less cooling) w.r.t. Si
‘laundry line’
‘balloon’
string: power, chip support, cooling
in 2030….
Minimum Material Budget
(% rad length)
Z = 0 mm
Z = +/-600 mm
Gossip detector (50 μm Si)
0.06
0.06
Cooling (stainless steel tube)
0.001
0.001
Power (max 0.28 mm aluminium)
0.0
0.3
Data transfer (max 1.7 mm kapton)
0.0
0.6
total
0.06
1
angle correction
x √2
0.09
x 2 x √2
3
New concepts for optical fiber data transfer
FE chip
laser
Interferometer
- rates up to 40 Gb/s
- geen materiaal en dissipatie op chip
- met 240 Gb/s: ‘all data to shore’: trigger possible
Virtual goal: ATLAS pixel vertex
- Ladder strings fixed to end cones
- Integration of beam pipe, end cones & pixel vertex detector
- 5 double layers seems feasible
data lines (Cu/kapton)
ladder cross section
casted aluminium
Stainless steel tube: - string
- power
- CO2 cooling
Gossip chip + InGrid
drift gap
cathode foil
ladder side view
ladder top view
First practical GOSSIP
with
CMS Vertex Pixel FE chip: PSI 46 (+ ATLAS FE pixel chip?)
- apply A-Si protection layer
- apply InGrid
- mount Gossips on pcb: ‘ beam telescope’
- Testbeam end 2006
Nijmegen, NIKHEF (,PSI?)
Gossip projects at NIKHEF/Univ. Twente/Saclay/CERN
-
Discharge protection
InGrid/TwinGrid/TripleGrid
Construction of detector: MediPix2 + SiProt + InGrid NewNext-1!
Construction of detector: TimePix + SiProt + InGrid NewNext-1
Gossipo chip developments
Development of ‘beam telescope’ Gossip demo
Vertex track simulations: signal development, DAQ data streams
Study of ‘services’ required for Gossip/SLHC:
assume dose rate of 12 tracks/(cm2 . 25 ns)
definition of cooling;
definition of data transfer connection;
definition of power lines
- Ladder prototype:
thermal modeling; Design of SS/Alu multifunctional string;
test (mech + thermal) of mechanical model
- CO2 cooling: ATLAS/NIKHEF project
- Ageing studies