l. tlustos, cernua9 meeting, nov. 2009 overview medipix
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L. Tlustos, CERNUA9 Meeting, Nov. 2009
Overview Medipix
L. Tlustos, CERNUA9 Meeting, Nov. 2009
Medipix ROC’s
• Medipix2 – Single pixel pulse processing
• event counting
• Timepix – Single pixel pulse processing
• Counting
• Time of Arrival
• Time over Treshold
• Medipix3– Distributed pulse processing
• “Spectroscopic“ event counting
L. Tlustos, CERNUA9 Meeting, Nov. 2009
MEDIPIX2 Collaboration
- U INFN Cagliari- CEA-LIST Saclay- CERN Genève- U d'Auvergne Clermont- U Erlangen - ESRF Grenoble - U Freiburg - U Glasgow - IFAE Barcelona - Mitthoegskolan - MRC-LMB Cambridge - U INFN Napoli - NIKHEF Amsterdam - U INFN Pisa - FZU CAS Prague - IEAP CTU in Prague - SSL Berkeley
http://medipix.web.cern.ch/MEDIPIX/
L. Tlustos, CERNUA9 Meeting, Nov. 2009
• University of Canterbury, Christchurch, New Zealand • DRT/LIST/DeTeCS/SSTM, CEA, Paris, France • CERN, Geneva, Switzerland, • DESY-Hamburg, Germany • The Diamond Light Source, Diamond House, Didcot, UK• Freiburger Materialforschungszentrum, Albert-Ludwigs-Universität Freiburg,
Germany, • University of Glasgow, Scotland, UK• Institute for Synchrotron Radiation, ISS, Forschungszentrum Karlsruhe, Germany • Biophysical Structural Chemistry, Leiden Univ., The Netherlands • NIKHEF, Amsterdam, The Netherlands • Mid Sweden University, Sundsvall, Sweden • IEAP, Czech Technical University, Prague, Czech Republic • ESRF, Grenoble, France• Universität Erlangen-Nurnberg, Erlangen, Germany • Space Sciences Laboratory, University of California, Berkeley, USA • Microsystems, VTT Information Technology, Espoo, Finland
MEDIPIX3 Collaboration
L. Tlustos, CERNUA9 Meeting, Nov. 2009
Current Applications• General purpose imaging detector
– Dental radiography– Mammography– Angiography– Dynamic autoradiography– Tomosynthesis– Synchrotron applications– Electron-microscopy– Gamma camera– X-ray diffraction– Neutron detection– Dynamic defectoscopy – Adaptative optics– Radiation monitor– Mass spectrometry
• Sparse data (mostly Timepix)– Tracking– TPC– Velocity map imaging
• > 150 publications in the last 5 years (http://www.cern.ch/Medipix) • Collaboration spokesman Michael Campbell ([email protected])
L. Tlustos, CERNUA9 Meeting, Nov. 2009
Hybrid-Pixel Detektor
p+
n-
ASICn-well
p-substrate
Semiconductor detector
Bump-bond contact
Charged particle
gm
Iin Vout
L. Tlustos, CERNUA9 Meeting, Nov. 2009
Medipix2 bump bonding
p+
n-
ASICn-well
p-substrate
Semiconductor detector
Bump-bond contact
Charged particle
gm
Iin Vout
CMOS ROpitch 55 µm
SENSORpitch 55 µm
L. Tlustos, CERNUA9 Meeting, Nov. 2009
Medipix ROC’s overviewMEDIPIX2 Timepix MPX3 (design)
Technology CMOS 0.25 mm CMOS 0.25 mm CMOS 0.13 mm
Type counting counting Counting , Single pixel/
Time over Threshold Counting, charge summing
Time of arrival
Pixel size [um] 55 55 55/110
Matrix 256 x 256 256x256 256 x 256
Area mm2 196 196 196
Pixel no. 65536 65536 65536
Pixel density [mm-2 ] 330 330 330
Pixel noise ENC 140 e 90 e 75e / 150 e
Threshold dispersion 100 e 60 e 55 / 100 adj.
Read-out scheme synchronous synchronous synchronous
Read-out mode full frame full frame full frame
continuous
Global threshold 1000 e 650 e 1000 e
Read-out time 10 ms, 300 ms 10 ms, 300 ms <10 ms
Counter depth 13 13 1, 4, 12, 24
No threshold 2 1 8/4/1
Radiation hardness ~200 krad ~200 krad ~500 Mrad
References:http://medipix.web.cern.ch/MEDIPIXThesis X. Llopart: Design and characterization of 64K pixels chips working in single photon processing modeThe Medipix3 Prototype, a Pixel Readout Chip Working in Single Photon Counting Mode With Improved Spectrometric Performance
L. Tlustos, CERNUA9 Meeting, Nov. 2009
Medipix2 Pixel
Analog Digital
Preamp
Disc1
Disc2
Double Disc logic
Vth Low
Vth High
13 bits
Shift Register
Input
Ctest
Testbit
Test Input
Maskbit
Maskbit
3 bits
threshold
3 bits threshold
Shutter
Mux
Mux
ClockOut
Previous Pixel
Next Pixel
Conf
8 bits configuration
Polarity
• Positive und negative input signals→ alternative detector materials (GaAs, CdTe …)• Charge sensitive preamplifier with leakage current compensation per pixel• 2 Discriminators with globally adjustable threshold• 3-bit threshold adjustment per pixel• Counter aktiviation via external shutter signal• 1 test-bit and 1 mask-bit per pixel• 13-bit Pseudo-random counter
L. Tlustos, CERNUA9 Meeting, Nov. 2009
Medipix Signal Processing
N+ P+
Si
Counter:
+
AmplifierComparator
000001
Threshold level >> electronic noise Þ No false counting.
Digital integration (counting)Þ No dark current.
Unlimited dynamic range and exposure time.
Detected count obeys poissonian distribution
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Pixel electronics
Thresholdlevel
Particle count
L. Tlustos, CERNUA9 Meeting, Nov. 2009
Energy window Medipix216.1-19.6 keV 21.6-25.1 keV 29-33.5 keV
36.9-40.4 keV 43.1-46.6
W-Röhre 50 kV2.5 mm Al
DE=3.5 keV
L. Tlustos, CERNUA9 Meeting, Nov. 2009
(Random) Application examples
Small animal CTSpectroscopic dataset for material reconstruction,Mars bio imaging., NZ
Mass spectrometry, Kiev, UAMPX in focal plane of spectrometer, ~10keV ions
PANalyticalIndustrial PartnerTechnology Transfer
L. Tlustos, CERNUA9 Meeting, Nov. 2009
(Random) Application examples
Small animal CTUniv. Erlangen
Neutron imagingLeft: Boron doped Micro channel plate, Univ. CaliforniaRight: LiF converter, IEAP Prague
Phase contrast imagingRight: Propagation phase contrast, IEAP PragueRight: Grating interferometer, PSI
L. Tlustos, CERNUA9 Meeting, Nov. 2009
Timepix
• Readout chip fully compatible with Medipix2 electronics/software
• 3 operational modes– Counting ( = Medipix2)
– Time over threshold mode (~ energy deposited)
– Arrival time mode
• Mode can be set in each pixel independently, allowing for concurrent energy and arrival time measurements
L. Tlustos, CERNUA9 Meeting, Nov. 2009
TimePix TOT (ADC) Mode withSilicon Detector Layer
N+ P+
Si
Counter:
+
AmplifierComparator
000001
Threshold level >> electronic noise Þ No false counting.
Digital integration (counting)Þ No dark current.
Unlimited dynamic range and exposure time.
Detected count obeys poissonian distribution
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Co
mm
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Pixel electronics
Thresholdlevel 007003
Particle countEnergy
L. Tlustos, CERNUA9 Meeting, Nov. 2009
Micromegas• A novel approach for the readout of a TPC at the future linear collider
is to use a CMOS pixel detector combined with some kind of gas gain grid
• Using a bare photon counting chip Medipix2 coupled to GEMs (A.Bamberger, M.Titov, Freiburg) or Micromegas (J.Timmermans, NIKHEF) demonstrated the feasibility of such approach
Micromegas
50um
L. Tlustos, CERNUA9 Meeting, Nov. 2009
GEM• A novel approach for the readout of a TPC at the future linear collider
is to use a CMOS pixel detector combined with some kind of gas gain grid
• Using a bare photon counting chip Medipix2 coupled to GEMs (A.Bamberger, M.Titov, Freiburg) or Micromegas (J.Timmermans, NIKHEF) demonstrated the feasibility of such approach
GEM
L. Tlustos, CERNUA9 Meeting, Nov. 2009
Timepix with 3-GEM detector• DESY testbeam in November 2006 (A.Bamberger, M.Titov)
L. Tlustos, CERNUA9 Meeting, Nov. 2009 Bunch period 176ns (~100ps)
L. Tlustos, CERNUA9 Meeting, Nov. 2009
Stopping Heavy Charged ParticlesTotal Energy Resolution
• Am241+ Pu239 combined source
• 5.2 MeV and 5.5 MeV a
• “Heavy” calibration extrapolation
Cluster volume (energy) spectrum (measured in air)
Gaussian fit sigma = 37 keV
0.67%
J. Jakubek et al. / Nuclear Instruments and Methods in Physics Research A 591 (2008) 155–158
Max. spatial resolution ~0.5 μm
L. Tlustos, CERNUA9 Meeting, Nov. 2009
11B HIMAC
@ 0 @ 60 @ ~90
Charge deposition studies with various Isotopes → Space Dosimetry
L. Tlustos, CERNUA9 Meeting, Nov. 2009
→ Quantum Dosimetry• Different particles have different event signatures use cluster
finding algorithms and decoding of event morphology New application: online dosimetry 15 MPX2 installed in ATLAS
241Am alpha source 55Fe X-ray source 90Sr beta source
L. Tlustos, CERNUA9 Meeting, Nov. 2009
Description of the detector
Medipix2 ASIC with 300µm Si sensor + USB interface
Neutron conversion structures:
1) LiF+50µm Al foil area
2) 100µm Al foil area
3) PE area
4) PE+50µm Al foil area
5) Uncovered area
L. Tlustos, CERNUA9 Meeting, Nov. 2009
Neutron efficiency calibrationFixed HIGH threshold (~200keV)
Calibrated efficiency:
Thermal: 1.41E-2 ± 7.11E-4 cm-2s-1
252Cf: 1.19E-3 ± 1.89E-5 cm-2s-1
AmBe: 2.86E-3 ± 5.46E-5 cm-2s-1
VDG: 7.23E-3 ± 5.81E-4 cm-2s-1
Thermal neutrons – 500s, 25meV
252Cf – 2000s, 2MeV (mean) AmBe – 2000s, 4MeV (mean)
PE
PE + Al
Al
Uncovered
LiF
X-ray image of conversion layers
Van de Graaff – 1000s, 14MeV
PE / PE+Al cluster count ratio:
252Cf: 10.70 ± 0.04
AmBe: 5.18 ± 0.03
VDG: 2.51 ± 0.03
L. Tlustos, CERNUA9 Meeting, Nov. 2009
Charge Transport in Planar Detectors
20 keV Photons300 m Si Sensor55 m Pixel Pitch 120 V sensor bias
• Mono-energetic Photon spectrum continuous spectrum with constant background and strong contribution of low pulse heights
• Even when using energy window spectroscopic information degraded
Mono-energetic Photons 20 keV
L. Tlustos, CERNUA9 Meeting, Nov. 2009
Spectral X-ray source
Photon Spectrum Detected spectrum
Simulation of the effective pulse height distribution as seen by pixel electrodes
Summation of signals from 3x3 pixel cluster
Corrected Pixel Spectrum
L. Tlustos, CERNUA9 Meeting, Nov. 2009
Charge Summing Implementation
• Off chip: Timepix like architecture– Digitization of energy deposited in pixel →TOT
– Sparse data, no overlaps → limited photon flux
– Fast readout necessary
• On chip: Medipix3– Communicating pixels
• Dead time/pileup limit given by shaping time
– Summing of 4 adjacent pixels
– 4 (8) Energy bins
L. Tlustos, CERNUA9 Meeting, Nov. 2009
55 m
The winner takes all • Charge is summed in every 4 pixel cluster on an event-by-event basis
Medipix3 - Charge Summing Architecture
• The incoming quantum is assigned as a single hit
L. Tlustos, CERNUA9 Meeting, Nov. 2009
MPX3 first results
• Just back from foundry
• Extensive testing going on
• + HW integration
• + Software
• …..
• Works, only few issues found
L. Tlustos, CERNUA9 Meeting, Nov. 2009
• In the pipeline– Next generation of RO systems
• RelaxD (Nikhef, Panalytical): 4 chip
• Mars (Canterbury): 6 chip
• Ruin (IEAP, Prague): single chip
• PRIAM for MPX3, ESRF
– New sensors • 150, 300 and 1mm thick Si
• GaAs, CdTe
• Amorphous Si, Amorphous CdTe (-> rad hard)
• Next ?– “Timepix2”, in discussion for LHCb velo upgrade: square pix,
fast ToT/ToA tracking
Outlook, in general
framerate ≥100 Hz
framerate ≥1 KHz
L. Tlustos, CERNUA9 Meeting, Nov. 2009
• 2nd Medipix in Roman Pot 1
• 3rd (4th?) Medipix in Roman Pot 2– In coincidence
• Tracking algorithm
• RO upgrade ≥100 Hz framerate
• Alternative sensors– Edgeless sensors (50 m insensitive area)
• Prototypes so far …
– Amorphous Si, amorphous CdTe
– 1 mm Si → solid state TPC
Outlook, in particular