Gianluigi Casse Michael - PowerPoint Presentation

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Gianluigi Casse Michael Moll University of Liverpool, UK CERN, Geneva, Switzerland

LHCC – 13.June 2012, CERN

RD50 Status Report 2012

OUTLINE:

RD50 Collaboration

Scientific resultsDefect and Material CharacterizationDetector CharacterizationNew Detector StructuresFull Detector SystemsRD50 Common ProjectsRD50 Work ProgramSummary

RD50

Slide2

The RD50 CollaborationRD50: 48 institutes and 261 members

38 European and Asian institutes

Belarus (Minsk), Belgium (Louvain),

Czech Republic (Prague (3x)), Finland

(Helsinki, Lappeenranta ),

Germany (Dortmund, Erfurt, Freiburg, Hamburg, Karlsruhe, Munich), Italy (Bari, Florence, Padova, Perugia, Pisa, Trento), Lithuania (Vilnius), Netherlands (NIKHEF), Norway (Oslo)), Poland (Krakow, Warsaw(2x)), Romania (Bucharest (2x)), Russia (Moscow, St.Petersburg), Slovenia (Ljubljana),

Spain

(

Barcelona(2x), Santander, Valencia

), Switzerland (CERN, PSI), Ukraine (Kiev), United Kingdom (Glasgow, Liverpool)

8 North-American institutesCanada (Montreal), USA (BNL, Fermilab, New Mexico, Purdue, Santa Cruz, Syracuse)1 Middle East instituteIsrael (Tel Aviv)1 Asian institute India (Delhi)

Detailed member list: http://cern.ch/rd50

M.Moll

06/2012

G.Casse and M.Moll, RD50 Status Report, June 2012

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2

-

Joined 2011/12

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RD50 Organizational Structure Co-Spokespersons

Gianluigi Casse and

Michael Moll

(Liverpool University) (CERN PH-DT)

Defect / Material

CharacterizationMara Bruzzi(INFN & Uni Florence)

Detector

Characterization

Eckhart

Fretwurst(Hamburg University)

Full Detector Systems Gregor Kramberger (Ljubljana University) Characterization ofmicroscopic properties of standard-, defect engineered and new materials pre- and post- irradiation

WODEAN:

Workshop on Defect Analysis in

Silicon Detectors (G.Lindstroem & M.Bruzzi

) Characterization of test structures (IV, CV, CCE, TCT,.)

Development and testing of defect engineered silicon devicesEPI, MCZ and other materialsNIELDevice modelingOperational conditions

Common irradiations

New Materials (E.Verbitskaya)

Wafer procurement (

M.Moll)

Simulations (V.Eremin)

3D

detectors Thin detectors

Cost effective solutions

Other

new structures

3D (

R.Bates

)

Semi

3D

(

Z.Li

)

Thinned

detectors

Slim Edges (H.Sadrozinski)

LHC-like tests Test beams Links to HEP Links electronics R&D Comparison:- pad-mini-full detectors- different producers Pixel Europe (T.Rohe) Pixel US (D.Bortoletto) Test beams (G.Casse)

New StructuresRichard Bates (Glasgow Uni) Giulio Pellegrini (CNM Barcelona)

Collaboration Board Chair & Deputy: E.Fretwurst (Hamburg) & J.Vaitkus (Vilnius), Conference committee: U.Parzefall (Freiburg)CERN contact: M.Moll (PH-DT), Secretary: V.Wedlake (PH-DT), Budget holder & GLIMOS: M.Glaser (PH-DT)

G.Casse and M.Moll, RD50 Status Report, June 2012

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WODEAN project (since 2005; 10 RD50 institutes, guided by G.Lindstroem and M.Bruzzi)

Aim: Identify defects responsible for Trapping, Leakage Current, Change of Neff

Method: Defect Analysis on identical samples performed with the various tools available inside the RD50 network:

C-DLTS (Capacitance Deep Level Transient Spectroscopy)I-DLTS

(Current Deep Level Transient Spectroscopy)TSC (Thermally Stimulated Currents)

PITS (Photo Induced Transient Spectroscopy)FTIR (Fourier Transform Infrared Spectroscopy)RL (Recombination Lifetime Measurements)PC (Photo Conductivity Measurements)EPR (Electron Paramagnetic Resonance)TCT (Transient Charge Technique)CV/IV> 240 samples irradiated with protons, neutrons and electronsmost important results published in Applied Physics Letters

… significant impact of RD50 results on

silicon solid state physics – defect identification

Defect Characterization - WODEAN

Example: TSC measurement on defects (acceptors) responsible for the reverse annealing

G.Casse and M.Moll, RD50 Status Report, June 2012-4-

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Summary – defects with strong impact on the device properties at operating temperaturePoint defects

EiBD = E

c – 0.225 eV 

nBD =2.3

10-14 cm2

EiI = Ec – 0.545 eVnI =2.310-14 cm2pI =2.310-14

cm

2

Cluster related centers

E

i116K = Ev + 0.33eV p116K =410-14 cm2Ei140K = E

v + 0.36eV

p140K

=2.510-15 cm2

Ei152K = Ev + 0.42eV

p152K =2.310-14

cm2

E

i

30K = Ec

- 0.1eV n30

K =2.310-14

cm2

V

2

-/

0

VO

-/

0

P

0/

+

H152K

0

/

-

H140K 0/-H116K 0/-Ci

Oi+/0BD 0/++

I

p

0

/

-

E30K

0

/

+

B

0/

-

0

charged at RT

+/-

charged at RT

Point defects

extended defects

Reverse annealing

(neg. charge)

leakage current

+ neg. charge

(current after



irradiation)

positive charge

(higher introduction after proton irradiation than after neutron irradiation)

positive charge

(high concentration in oxygen rich material)

Measured defect parameters serve as input for simulations

G.Casse and M.Moll, RD50 Status Report, June 2012

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Microscopic Defects

Challenge: Characterize defects responsible for trapping and leakage current

New approach

: Characterize defects responsible for trapping by their de-trapping behavior.

Method: Standard Transient Charge Technique (660 nm); recording & analysis of transient after current pulseG.Casse and M.Moll, RD50 Status Report, June 2012-6-

De-trapping time constants

Electrons:

t

e

= 2-40 ms (for 10-50°C)Holes: th= 1-10 ms (for 10-50°C) (two levels observed)[

G.Kramberger et al., 2012 JINST 7

P04006; 18th RD50 Workshop, Liverpool ][

M.Gabrysch, 20th RD50 Workshop 2012, Bari]

Defect parameters

2

µs illumination

de-trapping

i

ntegrate over

pulse

Arrhenius plot

for time constants

e

xtract defect parameters

Slide7

Edge-TCT to Study FieldsStudy of Electric field inside silicon sensor very challenging problemNew tool (2010): Edge-TCT (Transient Charge Technique)

Illuminate segmented sensor from the side with

sub-ns infrared laser pulsesScan across the detector thicknessRecord current pulses

as function of depthExtract rise time and collected total charge

Reconstruct the electric fieldExpectations

Significant electric field only in depleted volumeCharge generated in ‘undepleted’ part of detector is lost[Edge-TCT, G. Kramberger, IEEE TNS, VOL. 57, NO. 4, AUGUST 2010, 2294][N.Pacifico, 20th RD50 Workshop, Bari, 2012]G.Casse and M.Moll, RD50 Status Report, June 2012

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Slide8

Edge-TCT – Example – Drift velocitySensors: MCZ and FZ p-type ministrip sensors

(pitch: 80mm, width 20m

m)Irradiation: 1016 p/cm

2 with 24 GeV/c protons (6.1×10

15 neq/cm

2)Annealing: Isothermal at 60°C (results after 560 min shown below)Presence of electric field throughout sensor (although depletion voltage expected to be > 6000 V)MCZ: High electric field at back electrode (but not ‘useful’ for this p-type sensor) At this annealing stage both sensors give the same signal (as measured with beta particles on Alibava CCE system)~7400 electrons (most probable) at 1000 V[

N.Pacifico

, 20

th

RD50 Workshop, Bari, 2012]

FZMCZFront electrode (n-p junction)Back electrode (p+ contact)

Front electrode

(n-p junction)

Back electrode (p+ contact)

G.Casse and M.Moll, RD50 Status Report, June 2012

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Slide9

Charge Multiplication9

Ref: Diode:

J.Lange et al, 16

th RD50 Workshop, Barcelona Strip: G.

Casse et al., NIMA 624, 2010, Pages 401-404 3D: M.Koehler

et al., 16thRD50 Workshop, Barcelona

Charge Multiplication

observed and characterized after high levels of irradiation

with different techniques and in several different types of devices

Diodes

(

F

eq

=1016 cm-2)Leakage Current & Charge Collection

Strip sensors

(

F

eq

=5×1015 cm-2, 26 MeV p)Charge Collection (Beta source,

Alibava)

3D sensors

(

F

eq

=1-2×10

15

cm

-2

)

Charge Collection (test beam)

140

m

m thick device

300

m

m thick device

Questions:Can we simulate and predict charge multiplication ?Can we better exploit charge multiplication?G.Casse and M.Moll, RD50 Status Report, June 2012

Slide10

Characterizing Charge Multiplication10

Long term annealing

of strip

sensors

(HPK, 320

mm thick, 75mm pitch, FZ, n-in-p) CCE with SCT 128A (40MHz) Collected Charge from edge-TCT

Charge

multiplication observed

after long

annealing times for high voltagesEdge-TCT

Shows CM and gives indicationfrom which depthregion charge iscollected andmultiplied [I.Mandic, 17th RD50 Workshop, CERN, Nov. 2010]

[

M.

Milovanović

, 19th RD50 Workshop, Nov.2011]

G.Casse and M.Moll, RD50 Status Report, June 2012

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Understanding Charge Multiplication11

Exploring the effect of implant geometries

ratio

of strip implant to

pitch

effect of intermediate stripseffect of deeper junction

Status: Detectors produced, irradiated, measurements about to start.

Label

Strip pitch

(

mm)Implant width (mm)Intermediate strip width (mm)I8N802510I8W

80

2535I10N

1003333I10W100

3315I5N501515

I5W50156

Label

Strip pitch (mm)

Implant width

(mm)

NI8W8060

NI8M80

25NI8N80

6

NI10W

100

70

NI10M

100

33

NI10N

100

10

NI4W

40

27

NI4M4015NI4N406

G.Casse and M.Moll, RD50 Status Report, June 2012

Slide12

Strip detector Design with trenches

5, 10, 50

m

m deep trenches

5

mm wide in center of n+ electrode

Poly trench

Enhancing Charge Multiplication

Sizeable effect on

Charge Multiplication

Significant difference in CCE between standard and trenched detectors

Irradiation: 5×10

15

n

eq

cm

-2

(neutrons)

Implant

standard

[

D.Forshaw

, 19

th

RD50 Workshop, Nov.2011]

5

m

m trench

50

m

m trench

10

m

m trench

[

G.Casse

, Trento Workshop, Feb.2012]

G.Casse and M.Moll, RD50 Status Report, June 2012

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Slide13

RD50 Simulation Working GroupNew working group on simulations formed (Leader: V.Eremin, Ioffe)Using commercial TCAD and custom made software for simulationsFirst step: All participating groups performing device simulation using

identical geometry, defect parameters and defect concentrations.Simulations can predict double junction and avalanche effectsCompetition of charge trapping and avalanche processes

Focusing of the electric field and current near the collecting strips Leakage Current: plays important role in charging defects

Two effective defect levels (DA and DD) are sufficient to reproduce formation of

Double Peak electric field profile E(x)Examplen-on-p strip detector

d = 300 mm; pitch/strip width 80/20 (mm) G.Casse and M.Moll, RD50 Status Report, June 2012-13-[E.Verbitskaya, 20th RD50 Workshop, Bari, May 2012]

Slide14

Thin strip sensorsMeasurement of thin p-type strip sensors: 100, 140 and 300

mmAlibava, CCE with beta source

Thin (100 and 140

mm) devices give higher signal than 300 mm device for fluences

> 5×1015 n/cm2

G.Casse and M.Moll, RD50 Status Report, June 2012-14-[G.Casse, 20th RD50 Workshop, Bari, May 2012]1000 V

Simulation of sensors including avalanche and trapping

Competition of trapping and avalanche leads to a bump in this modeling

Modeling needs further tuning

… but is able to reproduce observed

double junction and avalanche effects

[

E.Verbitskaya, 20th RD50 Workshop, Bari, May 2012]

300

mm

140

mm

Slide15

Thin pixel sensorsThin pixel sensors produced: 75 and 150 mm thickness [MPI Munich]G.Casse and M.Moll, RD50 Status Report, June 2012

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n-in-p pixel sensors

Interconnect: Bump bonding and SLID tested

[

A.Macchiolo

, 20

th

RD50 Workshop, Bari, May 2012]

Slide16

New structures: 3D sensors3D sensors: Mastering the technology (CNM-Barcelona, FBK-Trento)Reproducible, reliable results

before and after irradiation

G.Casse and M.Moll, RD50 Status Report, June 2012-

16-

Double sided 3D

[A.Harb (IFAE Barcelona), 19th RD50 Workshop, Nov. 2011]

Slide17

Examples: New structures & technologies

RD50 slim edges project (reduce dead space around the active sensor)

G.Casse and M.Moll, RD50 Status Report, June 2012

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3D

stripixel

sensors

3D sensors connected on one side using double metal layer routing to columns

RD50 low resistance strip project

Improve punch through protection

(problematic of resistance to far end of strip)

“standard”

metal

a

dditional metal layer between implant and oxide

reduces resistivity

[

M.Ullan

, 20

th

RD50 Workshop, Bari, May 2012]

inactive area

slim edge

active area

guard rings

[V

. Fadeyev,

20

th

RD50 Workshop, Bari, May 2012]

Scribe

present: XeF

2

etch)

Cleave

present

: automated)

Passivate

oxide (n-type)

alumina ALD (p-type)

p-type

strip

(

1

st

metal layer)

n-type

strip

(2

nd

metal

layer)

3D electrodes

[

D.Bassignana

, 19

th

RD50 Workshop, Nov. 2011]

Slide18

RD50 – ALIBAVA Telescope (AT)

RD50 telescope

Alibava

based test beam telescope

Optimised for easy set-up

Fully integrated Alibava readout telescope and DUT have same readout Alignment, tracking and analysis to bestandardised. Characteristics of detectors before and after irradiation, as a function of bias voltage or other variables (temperature, influence of magnetic field, etc.) can be studied in real operation conditions. Preliminary results from DESY test beam availableNote: RD50 has access to other test beams performed in collaboration with e.g. CMS (HIP group)G.Casse and M.Moll, RD50 Status Report, June 2012-18-

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Recent RD50 WorkshopsRD50 Workshops: 2 per year1st : May/June outside CERN2nd: November at CERN

2.5 days19th : 21- 23 Nov. 2011 CERN

79 participants40 presentations20th

: 30 May – 1 June Bari56 participants42 presentations

Still very high interest in RD50 activities !

Last 2 workshops contained sessions dedicated to radiation damage in LHC detectorsorganized together with “Radiation Damage Inter-Experiment Working Group” (S.Gibson, ATLAS)Very fruitful exchange of information and knowledgeBenchmarking of the predictive power of radiation damage models developed within RD48/RD50Several questions addressed to RD50: e.g. What is the correct temperature scaling of leakage current?

G.Casse and M.Moll, RD50 Status Report, June 2012

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Radiation Damage in LHC ExperimentsSignificant radiation damage observed in the LHC ExperimentsTwo examples; see Radiation damage Inter-Experiment Working Group for more detailsG.Casse and M.Moll, RD50 Status Report, June 2012

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ATLAS Tracker: leakage current increase

Excellent agreement between model predictions and data (better than 20%)

[Taka Kondo (KEK, ATLAS), 20

th

RD50 Workshop, Bari]

[Dermot Moran (

LHCb

, Manchester), 20

th RD50 Workshop, Bari]

LHCb

–

Velo

: Depletion Voltage

Type inversion already observedGood agreement with “Hamburg Model”

Slide21

Ongoing common projectsRD50 common projects are reviewed by the RD50 management and receive (partly) funds from the RD50 common fund.Most recent projects:Low resistance strip sensors

(Lead: Miguel Ullan, IMB-CNM Barcelona)Production of thin Planar Pixel Sensors with n-in-p technology at CIS (Lead:Anna

Macchiolo MPI, Munich, Germany)Development of “slim edges” using cleaving and ALD processing methods (Hartmut Sadrozinski, SCIPP, USA)

Bump-bonding of ATLAS FE-I4 chips to silicon sensors (Daniel Muenstermann, CERN)Fabrication of new p-type strip detectors with trench at CNM to enhance the charge multiplication effect in the n-type electrodes.

(Lead: Giulio Pellegrini, CNM-Barcelona)Production of 4 inch wafers at Micron on existing mask set (

n,p MCZ and FZ) (Lead: Gianluigi Casse, Liverpool)Common purchase of MCz wafers (Okmetic) and FZ wafers (Topsil) (Michael Moll, CERN)Production of silicon sensors with modified junction (Lead: Gianluigi Casse, Liverpool) Support of production and distribution of Alibava systems (contact: M.Moll)Production of Planar Pixel Sensors with n-in-n and n-in-p technology at CiS (Lead: Anna Macchiolo MPI, Munich, Germany)G.Casse and M.Moll, RD50 Status Report, June 2012-21-

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Workplan for 2012/2013 (1/2)Defect and Material Characterization (Convener M.Bruzzi, INFN and University of Florence, Italy)Continue WODEAN program

Extend work on p-type siliconNew RD50 common project: Production of test structures on p-type siliconIntensify search for defects responsible for trapping

Modeling and understanding role of clustersDetector Characterization (Convener: E.Fretwurst

, University of Hamburg, Germany)Start-up of newly formed RD50 Simulation Working Group

(Leader: V.Eremin, Ioffe, St.Petersburg

, Russia)Comparison of results from different simulation tools (ongoing)Understand how to best implement the leakage current into the modelingExtend modeling on charge multiplication processesExtend experimental capacities on edge-TCT (implement set-up at more RD50 institutions)Parameterization of electric field (fluence, annealing time, etc.)Studies on charge multiplication processesCold irradiations and irradiations under biasContinue study on “mixed” irradiations Extend irradiation program using charged hadrons of different energyG.Casse and M.Moll, RD50 Status Report, June 2012-22-

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Workplan for 2012/2013 (2/2)New structures (Conveners: R.Bates, University of Glasgow, UK & Giulio Pellegrini, CNM Barcelona, Spain)

Continue edge-TCT studies on 3D sensorsEvaluate Stripixel sensors

Full detector systems (Convener: G.Kramberger

, Ljubljana University, Slovenia)Long term annealing of segmented sensors (parameterize temperature scaling)

Characterization of dedicated avalanche test structures (devices have been produced)Understand impact of implant shape and other geometrical parameters on avalanche processes

Combine results with edge-TCT data and simulations to get deeper understandingContinue RD50 test beam program and RD50 beam telescopeCold irradiations and irradiations under bias (segmented detectors)Continue study on “mixed” irradiations (segmented detectors)Continue RD50 program on slim edges and edge passivationStart program on fast sensors exploiting the avalanche processes in highly irradiated sensorsNew RD50 common project: Production and test of very thin segmented p-type sensorsEvaluate ‘low resistance strip’ sensorsLinks with LHC experimentsContinue collaboration on evaluation of radiation damage in LHC detectorsContinue common projects with LHC experiments on detector developmentsG.Casse and M.Moll, RD50 Status Report, June 2012-23-

Slide24

Some key results (in 2011/2012)Progress in understanding microscopic defectsDefects responsible for positive charge build up in DOFZ, MCZ and EPI and defects responsible for reverse annealing further characterized

First results on defects responsible for charge trappingSystematic analysis of the Charge multiplication mechanism.

Noise issue particularly important for exploitation of this feature in the Experiments

New dedicated sensors produced to test avalanche effects Simulation Working Group formed

Intensive simulation efforts started to understand charge multiplication mechanismsand progress towards comprehensive simulation tool

Consolidation of data obtained on p-type silicon strip sensorsFurther results on radiation tolerance and further results on long term annealingReverse annealing: Important results for controlling the reverse current and improving the signal by means of annealing. The accelerated studies of the CC(V) need accurate investigation of the acceleration factor at different temperatures before being used for predictions in the experiments Use of tools developed in framework of RD50: ALIBAVA & Edge-TCTEdge-TCT: Charge carrier velocity profile; Electric field profile; Charge collection profile, …Edge-TCT and TCT systems are now produced centrally and can be procured by interested groupsUse of the ALIBAVA readout system in many RD50 institutionsG.Casse and M.Moll, RD50 Status Report, June 2012-24-

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RD50 main achievements & links to LHC ExperimentsSome important contributions of RD50 towards the LHC upgrade detectors:

p-type silicon (brought forward by RD50 community) is now considered to be the base line option for the ATLAS Strip Tracker upgraden- MCZ

(introduced by RD50 community) might improve performance in mixed fields due to compensation of neutron and proton damage: MCZ is under investigation in ATLAS, CMS and LHCb

RD50 results on very highly irradiated planar segmented sensors

have shown that these devices are a feasible option for the LHC upgrade

Charge multiplication effect observed for heavily irradiated sensors (diodes, 3D, pixels and strips). Dedicated R&D launched in RD50 to understand underlying multiplication mechanisms, simulate them and optimize the CCE performances.Close links to the LHC Experiments:Many RD50 groups are involved in ATLAS, CMS and LHCb upgrade activities (natural close contact).Common projects with Experiments: Irradiation campaigns, test beams, wafer procurement and common sensor projects.Close collaboration with LHC Experiments on radiation damage issues of present detectors.G.Casse and M.Moll, RD50 Status Report, June 2012-25-

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Spare SlidesSome spare slides More details on http://www.cern.ch/rd50/Most results presented here have been shown on the 19

th or 20th RD50 Workshop

G.Casse and M.Moll, RD50 Status Report, June 2012

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Slide27

Edge-TCT – Data Analysis

V

fd

~16 V

v

e

+v

h

[

arb

.]

VELOCITY PROFILE

CHARGE COLLECTION PROFILE

RD50 Micron p-type sensor

[G.

Kramberger, 17

th

RD50 Workshop, Nov. 2010]

G.Casse and M.Moll, RD50 Status Report, June 2012

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Slide28

Long term annealing at RTStudy of annealing behavior of segmented sensors at room temperatureNeutron irradiated sensors: 2×1015 n/cm2 and 1×10

16n/cm2CCE: Alibava system

G.Casse and M.Moll, RD50 Status Report, June 2012

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[

G.Casse, 19th RD50 Workshop, Nov. 2011]

Slide29

SLID: Solid Liquid Inter-DiffusionG.Casse and M.Moll, RD50 Status Report, June 2012-29-

Slide30

Low resistance strip sensorsG.Casse and M.Moll, RD50 Status Report, June 2012-30-

Slide31

Slim edges projectG.Casse and M.Moll, RD50 Status Report, June 2012-31-

Slide32

Slim edges projectG.Casse and M.Moll, RD50 Status Report, June 2012-32-

Slide33

3D - StripixelG.Casse and M.Moll, RD50 Status Report, June 2012-33-