GARGAMELLE

Jean-Claude BRIENT LLR-IN2P3

The beginning of the experimental studiesof the electroweak theory

Now, we are talking about Now, we are talking about experimental studies experimental studies to understand the processes of the EW to understand the processes of the EW symmetry breaking symmetry breaking


What was our view at the beginning of the 4th ECFA workshop

What is the paradigm today

What has been achieved in the R&D

What remains to do in the short-mid termin the longer studies

What could be the future goal for the 5th ECFA studies

44thth ECFA/DESY workshop ECFA/DESY workshop Summary of theSummary of the Calorimeter studiesCalorimeter studies



Start from the PHYSIC program change with time (i.e. recent interest for the capability to measure the tau polarization)

Identify the need and how to fulfil it Make a list of requirements, like ∆Ejet, ∆Mdi-jet, photon IP, etc…

Look for pseudo-realistic deviceWhat is pseudo-realistic/not realistic is relatively elastic

Establish the distance between pseudo-realistic to realistic devicePrototype and test beam are clearly the best way to do it

The main principlesThe main principles (can be seen as obvious today, but …)


Our view at the beginning of the 4th ECFA

SHASHLIK

TILE for US-LCD-LD and ACFA

W-Si for TDR and US-LCD-SD

SHASHLIK

TILE for US-LCD-LD and ACFA

W-Si for TDR and US-LCD-SD

ECALECAL

TILE for TDR, US-LD, ACFA optimal size of tilephotodetectorsS/N at mip

Digital for TDRis it real effect ?shower size ? energy resolution ?

TILE for TDR, US-LD, ACFA optimal size of tilephotodetectorsS/N at mip

Digital for TDRis it real effect ?shower size ? energy resolution ?

HCALHCAL

Energy resolution single particle(10%/E was a “good’’ argument)

Pion/electron separation

Importance of performancein multi-jet events (not quantified)

Energy resolution single particle(40%/E was a “good’’ argument)

Importance of performancein multi-jet events (not quantified)


The Graal is the jet businessDi-jet mass resolution, lepton tagging in jet environment,etc…

Shower to shower separability separation charged hadrons/photon and charged hadrons/neutral hadrons Give access to the best possible Ejet and di-jet mass resolution

Lepton identification in jet electron, mu and tau tagging in jet Identification of jet flavor, W vs Z, etc…

Needed to see a signal at 5 Higgs self-coupling and ?? ttH ,…??

Dependence on the measurement precision Higgs BR in WW

WL coupling (W+W– versus ZZ)

e+e– W+W–,ZZ à s=800 GeV=0.6 =0.3

Mass

e j

3j 4

G

eV

Masse j1j2 GeV

Divergence on the realization Divergence on the realization ……

Admitted by the community, we want to be as close as

possible from a ”bubble chamber” picture

for each event


Totally segmented with fine granularityTotally segmented with fine granularitybest choice would be silicon-tungsten,

CALICECALICE collaboration US-SD detector US-SD detector



Tungsten-silicon sampling calorimeterTungsten-silicon sampling calorimeter (20 to 40 layers) Corresponding to about 10001000 to 3000 m3000 m2 2 of silicon detectorof silicon detector

The pad sizepad size would be from 0.5 to 1 cm0.5 to 1 cm22

(in the region of the Molière radius )Overall it means about 30 Million channels !!!!30 Million channels !!!!

Tungsten-silicon sampling calorimeterTungsten-silicon sampling calorimeter (20 to 40 layers) Corresponding to about 10001000 to 3000 m3000 m2 2 of silicon detectorof silicon detector

The pad sizepad size would be from 0.5 to 1 cm0.5 to 1 cm22

(in the region of the Molière radius )Overall it means about 30 Million channels !!!!30 Million channels !!!!


Silicon detector for HEP - Cost evolution

Used in the TDR

cos

t/are

a (

$/cm

²)

Moore's Law for Silicon Strip Detectors

10

2

1

4”6”

Blank wafer price 6'' 2$/cm2

Wafer sizeNumber of masks (x 0.5 )Industrial Yield (x 2 )Use of 8'' wafers ?

For a W-Si calorimeterFor a W-Si calorimeter

Com

pila

tion

fro

m H

.Sad

rozi

nski

(U

CS

C)

The goal is << 2 $/cm2

ATLAS

CMS

▶ About 1.5 $/cm2 following Korean estimation ▶ About 1.0 $/cm2 following Russian estimation

Silicon mini-workshop –Silicon mini-workshop –EWHA Univ.- Seoul August 2002EWHA Univ.- Seoul August 2002

YEAR


TPCTPC

ECALECALHCALHCAL

MODULEMODULE

Detector slab

tungsten


ECAL general view

3rd structure (3×1.4mm of W plates)

370 mm

180 mm

Silicon wafer

2nd structure (2×1.4mm of W plates)

VME/…

HCAL

VFE

Movable table

ECALBeam

monitoring

Global view of the test beam setup

BEAM

1st structure (1.4mm of W plates)

Detector slab

370 mm

Prototype overview


PCBPCB

ECAL W-Si. prototype in test beam in 2004 ? 2005 , Where ?? ECAL W-Si. prototype in test beam in 2004 ? 2005 , Where ??

WaferWaferWaferWafer VFE chipVFE chipVFE chipVFE chip

PadPadPadPad

Al. ShieldingPCB (multi-layers)( 2.4 mm)

Silicon wafer(0.525 mm)

Tungsten(1.4 mm, 2×1.4 or 3×1.4 mm)

8.5

m

m

Composite structure (0.15 mm / layer)

Transverse view






Reality of the cost evolution ?However, remember that it is possible to go down

by factor 2 on the Si. AreaIs it enough ??

Partially segmented with fine granularityPartially segmented with fine granularity Italian choice , LCCAL LCCAL

3 silicon layers + scintillator tiles

ACFA choice,ACFA choice, 3 fiber devices + scintillator tiles

Partially segmented with fine granularityPartially segmented with fine granularity Italian choice , LCCAL LCCAL

3 silicon layers + scintillator tiles

ACFA choice,ACFA choice, 3 fiber devices + scintillator tiles

If not enough on the cost reduction


LCCAL prototypePM’s

TilesSi planes

Tiles surrounded by holder structure for PM

LCCAL under test @ BTF in Frascati

Fibers inside collectorIn front of PMs


• 6 sensors /motherboard with serial readout.

• Status of production: – 16 sensors available– 2 motherboards fully and 1 partially

equipped (252 pads/board)

Si Pads inserted in proto 28-3-03

7 cm

6 cm

~1 c

m

~1 cm

Lccal: Si Pads design & production OK Mar 03 Sensors from

IET (Warsaw)


Calibration applied

3 e- 2 e- 1 e- E

E

Ebeam (MeV)

11.5%E

Nphe>5.1 /layer →Cal(45 layers) ~

250 MeV/Mip ~ 800Npe/GeVLight uniformity better than 20% OK also @ BTF (E ~500 MeV)

From Cern

TB

1. Photoelectron stat. Negligible

2. Sampling term 11.5% as in MC

3. Uniformity of light collection still at a level < 10% using all layers. Effect on resolution to be evaluated at next Cern TB (Aug 2003)

Good linearity vs particle multiplicity

Lccal: energy resolution and linearity for Tiles

From BTF te

st


ACFA ECALACFA ECALKEK, Kobe, Konan, Niigata, Shinshu and Tsukuba

Tile/Fiber Sampling Calorimeter• Hardware Compensation• Design Flexibility• Reasonable cost• Well-established thechnology• Sufficient granularity for EMCAL ?

Scintillator tile of 4 x 4 cm

EMCAL design1) Tile of 4cm x 4cm (7.1Xo)2) Strip Arrays (x,y) of1cm-widthSub-system R&Da) SHmax:direct-attached APD and WLS-readout.b) Super-multi-channel photo -detectors.Present status and future plans1st exp. just finished on Nov.14 for 1(partial), 2, and a.

2nd exp in November 2003November 2003 with 1(full) and b. Note the date


Shower width(due to density)

A.Sokolov (IHEP)

Totally segmented with fine granularityTotally segmented with fine granularitybest choice would be gas detector + radiator

CALICECALICE collaboration

Famous Digital HCAL



Famous Digital HCAL

Slope = 23 hits/GeVDigital Analog

Energy resolution(due to trunc. Landau)

S.Magill (ANL)


Resistive Plate: Glass or Bakelite

HV

Gas

Pick-up pad(s)

Graphite

Mylar

RPC’s design in US groups

№ Item avalanche streamer 1 2 3 4 5 6 7 8 9

10

Working mixture HV working point, kV Induced charge, pC Threshold on 50, mV Efficiency, %

Q / Q Pad multiplicity Noise, Hz/сm2 Rate capability, Hz/сm2 Ageing effects

TFE/Iso/SF6=93/5/2 8.4 3.4 1-2 >99 ~ 1 1.5

~ 0.5 300 no

TFE/Iso/Ar=85/10/5 7.0 300

50 - 200 ~95

~ 0.6 1.4 - 1.5

~ 0.1 4 - 5

observed

Results

from Russian groups


The key point of the costing is the readout electronics

Readout Board proposedBy JINR-DUBNA

The number of channels is VERY LARGEi.e. just for the prototype, it is about 200 000 to 400 000 channels

Readout Board proposedby LLR (TDR 01)


IV. Design work on the electronic readout

System overview

I RPC ASIC located on the chambers

II Data concentrators funnels data from several FE chips

III VME data collector funnels data from several data concentrators

IV External timing and trigger system




Famous Digital HCAL



Famous Digital HCAL

Partially segmented with medium granularityPartially segmented with medium granularity CALICE collaboration

9 layers of projective scintillator tiles(from 5x5cm to 20x20cm)

ACFA choice,ACFA choice, 4x4 cm projective scintillator tiles

Partially segmented with medium granularityPartially segmented with medium granularity CALICE collaboration

9 layers of projective scintillator tiles(from 5x5cm to 20x20cm)

ACFA choice,ACFA choice, 4x4 cm projective scintillator tiles

If real data largely downgraded

Reality of the simulationEnergy Resolution as well as shower width

Are better in GEANT4 Is it true in real world ??


Details of TFS Optimisation Studies

Centre/straight WLS-fibre Diagonal/bent WLS-fibre

No stress on fibre,fibre refl. =tile reflector

Double looped fibre •strong fibre bend,•most stress on fibre,•probably ageing damages,•fibre end fibre reflector inside tile >>> special reflective coating needed ?

L=7,85cmL=5cm

L=31,4cm 1.1 mm hole in center •drilled and polished? •could it be made during tile moulding?

more stress on fibre,fibre refl. =tile reflector

clear RO fibre to couple:1-3.5m in detector,light attenuation <18%

L=7.85cm


The actual achieved LY for the TFS, Kuraray, WLS-fibre

3M-Super Radiant Reflector

Scintillator BC-408,

All together: 100% reflectivity at fibre end

Treatment direction

22+/-1.5 pe (BC-408, Aug. 2002)

>> 26 (new results from ITEP)•both Russian scintillators have ~ 2/3 of BC-408 LY•~20% more LY can be expected by improving polishing of WLF-fibre end,•no gluing needed anymore

Light yield/tile


test of the W-Si ECAL (CALICE)

ACHIEVED by the calorimeter ACHIEVED by the calorimeter studies studies

in thein the 4 4thth ECFA workshop ECFA workshop

homogeneity of response how to do the tile ? fiber shape, choice of the fiberWhat is the smallest size with a good S/N at MIP ?

5x5cm (CALICE AHCAL) , 4x4cm (ACFA) , 9cm2 (CALICE NIU) Where to do the readout ? - close (Si-pm) - far (APD multi-anode)

test of the W-Si + tiles (LCCAL)

test/validation of the technical problem of integration (30 layers in 18cm)mechanical assembly , mechanical tolerance,…VFE seems in good shape, use of amorphous silicon for AC coupling, …

test of the technical feasibility…mechanical assembly , mechanical tolerance,… First results in beam test of the digital HCAL (CALICE)

Energy measurement wit digital device (GEANT4) test with pad size, …can we do it with RPC (GEM), Geiger Chamber,…. RPC’s design, Simulation studies (energy resolution, shower width), test of the tile HCAL (CALICE) DESY,ITEP,JINR,LPI,MEPhI,Prague…, KEK,… NIU

ANL, IHEP, JINR, NIU, SNU , UTA, …

Como, LNF,Padova,Trieste

France, U.Kingdom, MSU, Prague,….


AND NOWAND NOW

Prototype in construction / test validation of technical aspect well advanced and will continue

Prototype in test beam (2004 – 2006)physics results (specially the hadronic shower pattern in GEANT4)

Diversity of approach interesting at this level

LEVEL of SEGMENTATION for ECALfor HCAL

LEVEL of SEGMENTATION for ECALfor HCAL

The road for the 5th ECFA , (2 next years) is relatively clear

TECHNICAL WAY to do it for ECALfor HCAL

TECHNICAL WAY to do it for ECALfor HCAL

Documents

GARGAMELLE