Particle flow calorimeter with ASIC readout

Elmaddin Guliyev

LLR-Ecole Polytechnique, CNRS/IN2P3Palaiseau, France

ASIC readout for Electomagnetic Calorimeter for future

Linear Collider Experiment

Higgs particle predicted by the Standard Model – 1964

LHC started to exploration of this particle at TeV scale with proton beam...

Question?

Is the Higgs boson fundamentalparticle or composite?

Is it part of a more complicated electroweak sector?

Does it universally couple to all matter proportionally to mass?

The LHC can only partiallyanswer these questions.

How we will explore the answers of that questions?

Physics motivation

International Linear Collider (ILC) experiment will explore the depth answer ofquestions related with Higgs boson.

ILC menu:

Detailed study of Higgs boson

Search super-symmetric particles

Study of physics:W, Z particles

Top quark .....

ILC – different approach than LHC

Electron-positron collision at TeV scale

Clean environment – low QCD background compre to LHC

Precise measurements

ILC tunnels [http://www.linearcollider.org]

Physics menu

Hadron process resultining in final states containing many jets.four componenets: charged particles, photons, neutral hadrons and neutrinos

the jet energy is carried:60% by charged particles (hadrons),30% by photons 10% by neutral hadrons

Developed technique – Particle Flow (PF)reconstruction of the four-vectors

of all visible particles in an event

To measure the : momenta of charged particles ==> tracking detectors Photon energy ==> electromagnetic calorimeter (ECAL) neutral hadrons ==> hadron calorimeter (HCAL)

Particle Flow Calorimetery – new Concept of CALORIMETER

Particle Flow Method

International Detector (ILD)

e-e+ collision at TeV scaleHigh luminosity – low rate

Tracking system:Vertex Pixel (or TPC) detector

Calorimetery: ECAL – tungsten Absorber, silicon pixel Sensor detector material

HCAL – tungsten/steel absorber, gaseous resistive plate chamber (RPC) detector

Whole system will be placed 5 T solenoid magnetic field

ILD Detector

Electromagnetic Calorimeter for ILC

Very good jet resolution > Fine granularity > Silicon wafer

Compact > sandwich (sampling) calorimeter > W (tungsten) plate as absorber

Dynamic range ~ few 100 MeV – 500 GeV / 1 TeV

Readout electronics integration to active elements of ECAL > ASIC (Application Specific Integrated Circuit)

Prototype for ECAL

Prototype of Si-W ECAL

ASIC+Si Wafer

Tested with electron beam (DESY)

Tested with pulse generator at LLR

Tested with cosmic muon at LLR

6 layer

1 layer

ASIC readout – concept developed due to requirement of physics program. The requirements are:

* Small size* Low noise* Low power* Large dynamic range * Large number readout channels

Prototype SKIROC

64 channelDual gainDynamic range:0.5 – 2000 MIP (minimum ionizing particle)

ASIC chip – has been designed to match the ILC beam structure. The complete readout process needs at least 3 different steps:

a. acquisition phaseb. conversion phasec. readout phased. possibly idle phase

Implemented Technique:

POWER PULSING >

-high channel density-high power dissipation

NoisePedestal (baseline)

En

egy

(ch

arg

e)

Analog output of ASIC

Signal processing for ASICSKIROC

- analog waveform at the output

of the pre-amplifier andthat at the output of the shaping amplifierwere observed using the monitor linesby injecting a charge.

For the charge (energy)information thegenerated signalfalling edge positionedin to the maximum ofsignal out of shaper unit.The hold signal can help to digitize thethe amplitude of analog waveform as a energy information, baselineto study the noise level.

Pedestal (baseline) distribution

Less noise valueNegligible baseline fluctuations

Verification of ASIC work abilityWith injected charge:

LinearityHold (delay)Gain

Setup with electron beam

e- beam

6 x [ silicon wafer + FEV8 + 4xSKIROC+DIF] W plate

e- beam

Performance study with electron beam:Energy of electron beam was 1-5 GeVRate 1 kHz6 detector layer

Pedestal

First MIP position

Second MIP position

Third MIP position

1st MIP = 356 +- 6.5 ADC Count2nd MIP = 426 +- 16.2 ADC Count3rd MIP = 498 +- 24.3 ADC Count

Hit map for 1 GeV electron beam

Shower radius developmentfor different radiation length

1. ASIC readout concept developed for ECAL.

2. It verified using high energy electron beams.

3. Parameters of ASIC; delay, gain, trigger threshold, time constant etc. performed with pulse generator and electron beam.

4. The chain of readout electronics based on ASIC is almost completed.

SUMMARY