1

ALICE: Progress and Plans

Progress on

- Selected Detector Systems

- Infrastructure in Point 2

- CERN Hostlab responsibilities

6th ST Workshop, 1.4.2003 C.W Fabjan

Emphasis on the multifaceted collaboration with many CERN Technical Groups

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ALICE : AIM of RESEARCH

ALICE : A Large Ion Collider Experiment at LHCAim : through collisions very energetic nuclear matter ( Lead nuclei with Lead nuclei )→ compression and heating of nuclear matter→ induce ‘Phase Transition’ to ‘Quark-Gluon Plasma’→ create and study the properties of this new form of matter; thought to have filled all of our Universe 10-5 after Big Bang

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Implantation of ALICE in Point 2

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LAYOUT : 3D VIEW of ALICE

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ALICE Detectors : CERN ALICE Team Responsibilities

Pixels : are very small ( typically 0.05*0.2 mm2 ) silicon detection cells, used for very precise particle tracking

Alice has 10 Million such pixels in its ‘Pixel Detctor’

- Electronics Development with EP/ED

- Novel Connectivity with EST/DEM

- Consulting on metallurgical questions with EST/SM

- Cooling issues with ST/CV

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SCHEMATIC VIEW: PIXEL SENSORS coupled toREADOUT-CHIP with ‘SOLDER BUMPS’

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Pb-Sn Bump Bond

SEM Pictures(CERN, VTT)

Bonding Pad on ALICE Pixel Chip

P. Riedler

Work done in collaboration with EST/SM

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95

13.8

28

11

47

8

LASER DIODE

PILOT MCM (top view)

Laser + 2 pin diodes

DigPILOT

GOLAna

PILOTFlashADC

Space reserved for connectionsbetween mcm and extender

Space reserved for connectionsbetween pixel bus, mcm and extender

M. Morel

Novel connectivity developed by EST/DEM

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READOUT CHIP

PIXELS DETECTOR

CARBON FIBER SUPPORT

150 to 200µm

290µm

50µm

150 to 200µm

Thermal grease

glue

Aluminium

Kapton

Pixel bus connections

COOLING TUBE

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DETECTOR

PIXEL CHIPMCM

PIXEL BUS

COOLING TUBE

PIXEL BUS AND PILOT MCM CONNECTIONS (1)

SDM comp

LASER DIODE

0.28

0.50

Space reserved for connections between Pixel bus & MCM(DATA, CONTROL ,REF,JTAG)

0.430.35

0.10

0.23

PIXEL BUS POWER SUPPLY100 BONDING WIRES

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MODERN MATERIAL SUPPORT STRUCTURES NEAR VACUUM CHAMBER

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ALICE DETECTORS : CERN ALICE TEAM RESPONSIBILITIES

TPC (Time Projection Chamber) : distance of

tracks are ‘projected’ on (drift) ‘Time-Axis’ALICE is building the world’s largest ( 100 m3 ) TPC

‘Field Cage’ : Detector and Track Drift volume with 100 kV electrode

in collaboration with EP/TA2 (‘Technical Assistance)

Readout electronics : > 700,000 channels

complex signal processing detector developed in collaboration with EP/ED

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CONCEP OF THE TPC

E

B

Drahtkammer mit “Padauslese”

N–Messungen

Verbreiterung durch Diffusion

Ionization produced by charged particles is ‘projected’ under the influence of a strong electrical field on Readout planes

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ALICE TPC: Detectorspecifications

• Gas Ne/ CO2 90/10%• Driftfield 400V/cm: • Space resolution: = 0.2mm• Pads(inner): 4x7.5mm• Pads (outer): 6x15mm• Magnetfeld : bis 0.5T

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ALICE TPC:during constructionConstruction accurracy in z =250m

Drahtkammer: 40m

Endplates : 250m

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ALICE TPC READOUT CHIP (ALTRO) in EP/ED

010011010001011101010011010001011110010011010001011010

01001101000110111010110011000111001010011010 010011010001101110010 010011010001101110010 010011010001101110010

BaselineCorrection

I

+

–

TailCancellation

BaselineCorrection

II

ZeroSuppression

010011010001101110010010011010001101110010010011010001101110010

DataFormat

Memory+

Multi-EventBuffer

010011010001011101010011010001011110010011010001011010

01001101000110111010110011000111001010011010 010011010001101110010 010011010001101110010 010011010001101110010

BaselineCorrection

I

+

–

TailCancellation

BaselineCorrection

II

ZeroSuppression

010011010001101110010010011010001101110010010011010001101110010

DataFormat

Memory+

Multi-EventBuffer

MAX SAMPLING CLOCK 40 MHz

MAX READOUT CLOCK 60 MHz

HCMOS7 0.25 mm (ST)

area: 64 mm2

power: 16 mW / ch

prototype delivery: Feb ‘02

300 samples (4800 Ch) tested

delivery of 4x104 chips: Dec ‘02

10- bit20 MSPS

11- bit CA2arithmetic

18- bit CA2arithmetic

11- bitarithmetic

40-bitformat

40-bitformat

10-bitarithmetic

16-CH Signal Digitizer and Processor

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STM PRESS RELEASE

“STMicroelectronics Developes World’s Most Advanced Data Acquisition

System-on-Chip Jointly with the ALICE Experiment at CERN”

“Success in major scientific research project will benefit many aerospace,

Medical and industrial applications”

November 25, 2002

ad ALTRO

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TPC PERFORMANCE : UNDERSTANDING THE THERMAL ENVIRONMENT

• Operation of the TPC requires temperature stability at the 0.1 K level

• Collaboration with ST/CV

• Using the (probably) most advanced, public thermal simulation program to study thermal environment

- Inside L3 Volume

(led e.g. to water cooled bus bars inside L3;

to definition of air flux through L3)

• NEXT

- inside ITS (to be finished)

- inside Muon Spectrometer (also with Orsay

participation)

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Temperature map of the L3 Interior

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ALICE : Simulation of particle tracks

• Simulation of particle tracks

• Collision of Pb-Pb Ions

• Total number of particles:

• approx. 10 000/coll.

• Shown is ‘time slice’ of 1 %

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ALICE DETECTORS : CERN ALICE TEAM RESPONSIBILITIES

HMPID (High Momentum Particle Identification)Velocity measurement of Cherenkov light Cherenkov light emitted by medium, if velocity of particle is faster the

velocity of light in mediumcos θ (Cherenkov light) = c/(v (particle) n (refractive index))

(similar to shock wave of supersonic airplane)And momentum measurement

Allows mass (m) determination, which characterizes (‘identifies’) particle

Novel ‘ Imaging’ Technique developed in collaboration with EP/TA 1 EP/TA 2

2βγc m p

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PRINCIPLE of the ALICE RICH (HMPID) Light detection with CsI-Photocathodes on Pad-Plane

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CsI photocathode quantum efficiency

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

5.5 6 6.5 7 7.5 8photon energy [eV]

CsI

ph

oto

cath

od

e Q

E

PC32 (@STAR)

PC33

PC34

PC35

PC37, PC39

PC38

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The Devil is in the DetailsThe Devil is in the Details

gold front gold front surface (0.4 surface (0.4

m)m)

nickel barrier layer nickel barrier layer (7(7m)m)

multilayer multilayer pcb with pcb with metalized metalized holesholes

CsCsII

Photocathode PCBsPhotocathode PCBssplit into two multilayersplit into two multilayercircuits (SMD connectors for FEE cards)circuits (SMD connectors for FEE cards)

GROUND PLANEGROUND PLANE40 c

m40 c

m

60 cm60 cm

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The HMPID proto-3 ( one sub-module of final detector) fully equipped with the full FEE/RO chain (3840

channels)

FEE (GASSIPLEX) cards

MCM (DILOGIC) card

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ALICE: INFRASTRUCTURE / HOSTLAB RESPONSIBILITIES

Hostlab responsibilities :formal responsibilities, such as providing

correct working environment; safe, useable Experimental Hall…

‘informal’ responsibilities : contribute to the success of visiting groups using CERN as their research facility;

- aim to cover activities, frequently not possible at outside institutes and for which CERN has the appropriate facilities and expertise

Success of CERN depends to a large degree on the perception of our outside colleagues on how well CERN manages their informal, collaborative responsibilities.

•Major engineering tasks

•Special technology groups with their expertise

•Special workshops as incubator for new technologies

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ALICE:PROGRESS ON INFRASTRUCTURE/HOSTLAB RESPONSIBILITIES

Cooling : in collaboration with ST/CV needs understood, workpackages (‘EP

definition’) established construction to start

Gas : in collaboration with EP/TA1 and ST /CV gas pipe routing essentially finished

Electricity : needs understood, workpackages established rack power distribution in collaboration with ST/EL

Cabling : major effort, for which we need to be included in the ST/EL cabling contract Detector Control: In collaboration with AT, IT,STSafety Detectors : in collaboration with ST/MACivil engineering: done by ST/CE

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Services Integration(2)

LV Bus Bars for the TPC, TRD & TOF detectors

Cooling fluid & gas pipes

DDL Fiber optic cables

Cables to CTPRB26 side of Detector

S. Maridor EST/IC & D. Gabriele EST/LEA

EXAMPLE: SERVICES THROUGH RB26 SIDE

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Pre-assembly of dipole magnet

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Muon magnet on special ST/CE base

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ALICE : Infrastructure / Hostlab responsibilities

• Transport and Cranes : collaboration with ST/HM

Transport : requirements for ALICE lees demanding

compared to ATLAS /CMS; but need availability of a 40- ton trailer for efficient

operation at Point 2

Crane operators : we have a highly professional Team at Point 2; Knowledge of experiment, environment and collaborators is essential for continued quality therefore

contracts must guarantee continuity over several years

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INTEGRATION : KEY MILESTONES FOR TECHNICAL COORDINATION IN 2003

April : Tendering of LV Bus Bars;Tendering of Muon Absorber Components

April: Muon Magnet Yoke arrives at CERN

May/June: Space frame and auxiliary Service frames assembled at CERN

July: Start of Bus Bard Installation on RB26 side

August: Muon Magnet Coils arrive at CERN

October:Power Tests of Muon Magnet

4th Q: install big support rails Close L3 RB 26 doorsConstruct Muon Spectrometer foundation

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ALICE :Conclusions

• ALICE, as the other LHC experiments, has progressed through the efficient, fruitful collaboration with ST and other CERN Technical groups

• ALICE, as the other LHC experiments, can only become reality through continued, successful collaboration with a large spectrum of CERN groups

• CERN will be judged by the quality of fulfilling its responsibility towards and expectations as Hostlab for the ~1200 ALICE collaborators

• CERN-ALICE Team is looking forward to a continued fruitful collaboration with ST Division during 2003, which will be a very critical year for ALICE