Report from the

the CALICE Collaboration

164 Physicists 26 Institutes 9 Countries 3 Regions

José RepondArgonne National Laboratory

CAlorimeter for the LInear Collider with Electrons

A calorimeter optimized for the Energy Flow measurement of multi-jet final states at the Future Linear Collider running at a center-of-mass energy 90 GeV and 1 TeV

Hadronic Calorimeter

• Analog readout – ‘Tile HCAL’

Germany, Czech, Russia…

• Digital readout – ‘DHCAL’

I Gas Electron Multipliers (GEMs)

Texas at Arlington

II Resistive Plate Chambers (RPCs)

Russia, USA (ANL, Boston, Chicago, FNAL)

III Scintillator

Northern Illinois

IV Short Drift Tubes (SDTs)

Protvino

Electromagnetic Calorimeter

• Silicon – Tungsten

France, UK + friends

• Silicon – Scintillator ‘LCCAL’

Italy Not part of CALICE

Will report on these

Others covered by individual talks at this workshop

CALICE ECAL

Fine granularity tracking calorimeter

Silicon – Tungsten sandwich

1 x 1 cm2 pads 40 layers

Simulated energy resolution

Prototype for test beams

30 layers Active area 18 x 18 cm2 9720 channels

Goal: first tests in 2004

)(/%11/ GeVEEE

Structure 1.4(1.4mm of W plates)

Structure 2.8 (2×1.4mm of W plates)

Structure 4.6(3×1.4mm of W plates)

ACTIVE ZONE

Metal insert

Detector slabs

60 mm

60 mm

Si Wafer with 6×6 pads

10×10 mm2

Front End electronics

(Cfi / W) structure type H

Silicon wafer

Shielding

PCB

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

mm

Composite structure (0.15 mm / layer)

Transverse view

Detector slab

PCB

14 layers Thickness 2.4 mm

ChipsChipsChipsChips

WaferWaferWaferWafer

PCB boardPCB boardPCB boardPCB board

PCB, Wafers, Chips…

Front-end electronics: ASIC

Second version being developed….

FLC_PHY1 FLC_PHY2• Preamp 16 gains (0.2, 0.4, 0.8, 1.6pF switchable)• Lower noise (input transimproved)• Shaper bigain differential• track & hold differential

• Preamp 1 gain (1.5pF)• Low noise (2200e-)• Shaper Mono gainunipolar• track & hold Unipolar

Pin-Pincompatibility

AmpOPA

OPA

MUX out Gain=1

MUX out Gain=10

1 channel

Measurements on FLC_PHY1

Linearity 0.3% Dynamic range 3.5 pC Noise 2200 e-

Pedestal dispersion σ=5mV

Satisfactory

Rear-end electronics

Developed in the UK

Use of CMS Back end

Schedule

Mechanical structure

Tungsten plates by end of 2003 Assembly in early 2004

FE ASICs

FLC_PHY2 tested by September Choice of ASIC Production completed by end of 2003

FE PCB boards

Built by February 2004

RE boards

Fabrication and assembly in Mar’03

Prototype in beam

Cosmic rays first half of 2004 Electrons by mid 2004 Hadrons in 2005

LCCAL

45 layers

25 x 25 x 0.3 cm3 Lead 5 x 5 x 0.3 cm3 Scintillator

3 layers of Silicon

1 x 1 cm2 pads at 2, 6, 12 X0

Not part of CALICE

Collaboration

Como, LN Frascati, Padova, Trieste

Concept

Lead/scintillator plus silicon

EE

Extensive Tests in Frascati Test Beam

Electrons and positrons

50 – 850 MeV Energy selection 1 % Up to 103 electrons/s

Energy resolution as expected Npe > 5.1/layer → p.e. statistics negligible Uniformity of light collection at 10 – 20 % level

Recently inserted Silicon pads

E (MeV)

)(/%5.11/ GeVEEE

Conclusions and Perspectives

LCCAL prototype

Almost fully working More Silicon pads are being constructed Third Silicon layer will be fully equipped

Test run at Frascati

Underway Energy response and resolution as expected Merging Silicon and Energy information: understand multiple hits (>1 e-)

Two test beams at Higher Energy in preparation

PS and SPS (in 2003)

Monte Carlo Simulation

Studies of hybrid technique to be initiated

Hadron Calorimeter

HCAL located inside 4T coil

Thickness

4.5 λ … Barrel 6.2 λ … Endcap

Cell structure

Iron 20 mm Active medium 6.5 – 10.0 mm

TESLA TDR

Two options

a) Analog hadron calorimeter with scintillator

b) Digital hadron calorimeter with …

Analog HCAL

Scintillator tiles

Area 5 x 5 → 25 x 25 cm2

Thickness 5 mm

Longitudinal segmentation

9 … Barrel 12 … Endcap

Strong R&D program

Tests of different plastic scintillator

Fiber routing optimization

Selection of wavelength-shifting fibers

Coupling of WLS-fibres to scintillator

Clear fiber selection

Connection of WLS and clear fibres

Photodetectors

A few examples…

Scintillator

PolyVinylToluene based → more expensive

BC-408, BC-404…

PolyStyrene based → less light

SCSN-81, Kuraray, BASF-143…

WLS Fiber Routing

Stress on fiber → ageing?

WLS Fiber

Diameter 1 mm, double clad

BC-91A BC-92 Y11(500ppm) …

Treatment of fiber end

Polishing End reflector

Treatment directionFiner sandpaper

Silicon – Photomultipliers SiPMsR&D at MEPHI (Moscow) together with PULSAR (Russian Industry)

R 50

h

pixel

Ubias

Al

substrate

ResistorRn=400 k

20m

42m

2 ns

2 mV

Overall size 1.5 x 1.5 mm2

Sensitive area 1 x 1 mm2

Gain 2∙106 at Ubias ~ 50 V

Number of pixels 576 → 1000

Recovery time ~100ns

4 – 8 photo-electrons576 pixelsUbias = 53 – 55 V

10 photo-electrons576 pixelsUbias = 54 V

15 photo-electrons1000 pixelsSiPM mounted on tile

0 5 10 15 20 25 30 35 400,0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

1,0

10-2

10-1

100

101

102

103

104

105

106

107

108

MIP Detection by one cell ( 3 Tiles + 3 SiPMs)

98% efficiency

Da

rk r

ate

, H

zThreshold, phe

MIP

de

tect

ion

eff

icie

ncy

With threshold at ~ 20 photo-electrons

Dark rate ~ 2 Hz MIP detection efficiency ~ 97.5%

Minical Array

Purpose

Cosmic rays starting in August

Light Yield Uniformity of response Calibration with MIPs Test of different photo-detectors Long term ageing effects

LED monitoring

Stability Dynamic range

Electron beam

Energy resolution Constant term Linearity

Stack

27 layers of 9 tiles 5 x 5 x 0.5 cm3 scintillator

APDs3 tiles/APD

MA-PMs3 tiles/pixel

SiPMs1 tile/SiPM

beam

beam

1. Enough LY from TFS (~200 photons at photodetector)2. APD’s and SI-PMs are the photodetectors which do the task3. Preamplifiers with low noise are essential (MIP-noise separation,calibration)4. Minical test to establish calibration precision in summer5. Now design of prototype boards for APD and Si-PMs (DUBNA)6. Photodetectors, large quantity to order in summer:

• 1000 APDs or• ~ 5000 Si-PMs or • both types in relevant quantities e.g. ~250/3500

7. Prototype stack (1m3) will be build in summer8. Assembly of PT-stack with TFS starts in Jan. 20049. Spring 2004 is used to set up and calibrate all channels with cosmics.

Slide by V Korbel shown at Amsterdam MeetingOutlook

DHCAL: Resistive Plate Chambers - RPCsOnly Russian effort (Protvino) for US effort see separate talk

Developed RPCs

Single gap of 1.2, 1.6 or 2.0 mm 1013 Ω∙cm window glass as resistive plates Tests with 16 pads of 1 x 1 cm2

Thickness 4.4 mm (without FEE)

Gas mixtures

Avalanche mode: TetraFluoroEthane : IB : SF6 = 95 – 98 : 5 : 5 – 2 % Streamer mode : TetraFluoroEthane : IB : Ar/N2 = 80 : 10 : 10 %

Tests with

Protvino test beam

Tests in avalanche mode

Efficiency and pad multiplicity versus High Voltage

To give a few examples…

Tests with different gases and thresholds

Best results for

HV = 8.2 kV Threshold = 2.2 mV

Efficiency ~ 99% Multiplicity ~ 1.4

Efficiency versus rate for avalanche and streamer mode

Pad multiplicity versus charge for different anode thicknesses

Noise rate versus High Voltage

Maximum rate

Streamer mode 4 - 5 Hz/cm2

Avalanche mode ~ 300 Hz/cm2

The thinner the anode

the smaller the multiplicity

At optimal operating point

~0.5 Hz/cm2

Comparison of operation modes

As an example for 1.2 mm gas gap…

Favored

Avalanche Streamer

Gas mixture TFE:IB:SF6 = 93:5:2 TFE:IB:Ar = 85:10:5

HV working point 8.4 kV 7.0 kV

Induced charge 3.4 pC 300 pC

Threshold on 50 Ω 1 – 2 mV 50 – 200 mV

Efficiency > 99 % ~ 95 %

σq/Q ~ 1 ~ 0.6

Pad multiplicity 1.5 1.4 – 1.5

Noise ~0.5 Hz/cm2 ~0.1 Hz/cm2

Rate capability 300 Hz/cm2 4 – 5 Hz/cm2

Ageing effects None Observed

Plans

December 2003

Beam tests with 20 layer ‘electromagnetic’ calorimeter 64 pads per layer

June 2004

Ready for production and assembly of 1 m3 prototype

DHCAL: Short Drift Tubes - STDs

Cell size 1 cm2 x 3 mm

Gas IB : Ar : TFE = 80 : 10 : 10

Efficiency and Multiplicity

as function of High Voltage

Currently using flammable gas exploring performance with other mixtures

Being developed in Protvino…

DHCAL: Readout schemes

Real challenge…. 1 m3 prototype: 400,000 channels!

IHEP Protvino Conditioning + FPGA + Serialiser

JINR Dubna Comparators + FPGA + VME

US groups Custom FE ASIC + concentrator + collector

Korea Testing entire chain of comparators and digital processing

Imperial College London

Adapting ECAL readout scheme to A/DHCAL

Readout at Protvino

Conceptual design

Readout for 64 channels

I Conditioning (analog)

II FPGA (digital)

III Serializer (readout of several FPGA)

Readout at Dubna

XILINXCOOLRUNNER-II

CPLD

COMPARATORS

COMPARATORS

Price ( $) Prototype 5000 ch Thr.

JINR Apl.+

CPLD

0.4

0.04

READY End of 2003

7-10 mv

Comp+

Sh. Reg.

0.35

0.04

+ 3-4

CMS ampl. US +

CPLD

0.37

0.04

READY Nov.

2003

US ?

2-5 mv

CMS amp.Bel +

CPLD

0.5??

0.04

READY Nov.

2003

? Minsk ?

3-6 mv

Bel. 0.5?? ??? 3-6 mv

HCAL: Mechanical Structure of 1 m3 PrototypeStructure

40 Layers Each 1 m2

20 mm steel plates Weighs 6 tons!

Issues

Material of absorber

Steel Stainless steel Tolerances on thickness, flatness

Active gap

Adjustable width Tolerances Support plates, e.g. 2 mm steel

Logistics

Tests in magnetic field, what B 1 or 2 stacks Who builds it

DHCAL meeting at DESY on June 30, 2003

CALICE meeting in Amsterdam on 31-March-2003

ECFA/DESY LC workshop in Amsterdam, April 1 – 4, 2003

http://www.nikhef.nl/ecfa-desy/flashindex.html

http://polywww.in2p3.fr/flc/agenda_dhcal_280203.html

DHCAL meeting in Paris on 28-February-2003

More information and upcoming meetings…

http://polywww.in2p3.fr/flc/agenda_CALICE_310303.html

http://www.hep.anl.gov/repond/DHCAL_Jun_2003_Agenda.ppt

A/DHCAL meeting at DESY around October 24, 2003