DEPFET detectors for - PowerPoint Presentation

Slide1

DEPFET detectors for future colliders. Activities at IFIC, Valencia

Terceras Jornadas sobre la Participación Española en los Futuros Aceleradores Lineales de PartículasUniversitat de Barcelona

C. Mariñas, IFIC, CSIC-UVEG

Carlos Mariñas, IFIC, CSIC-UVEG

Slide2

OutlookC. Mariñas, IFIC, CSIC-UVEG

Slide3

Vertexing in future collidersC. Mariñas, IFIC, CSIC-UVEG

This

requirements impose

unprecedented constraints on

the detector:

High granularity

Fast read-out

Low material budget

Low power

consumption

Vertexing

in future colliders

requires

excellent

vertex

reconstruction

and

efficient

heavy quark

flavour

tagging using low momentum tracks

DEPFET Measurements made on realistic DEPFET prototypes have demonstrated that the concept is one of the principal candidates to meet these challenging requirements

Slide4

DEPFET principleC. Mariñas, IFIC, CSIC-UVEG

Each

pixel is

a p-channel FET on a

completely depleted bulk

A deep n-

implant creates a

potential minimum for electrons under

the gate

(internal gate)

Signal electrons accumulate

in the internal gate

and

modulate

the

transistor

current

(400pA/e

-

)

Accumulated

charge can be removed by a clear

contactFully depletedLarge signalFast signal collectionLow capacitance, internal amplificationLow noiseTransistor ON only

during readout

Low power

Complete clear

No reset noise

Features

Slide5

Introducing the Valencia’s set upFaraday

cagePC for data acquisitionStack of

power suppliesLaser

Motorstages XYZComplete system

for air and liquid cooling

Cooling blocksAluminium

coilsPulse generator

C. Mariñas, IFIC, CSIC-UVEG

Slide6

Matrix characterizationC. Mariñas, IFIC, CSIC-UVEG

Full electrical optimization of matrices: This

implies scans

over a wide

range of the operating

voltages to achieve

the best

signal-to-noise ratio.Clear High/Low

Gate ON/OFF

BackBulk

CleargateSource

Calibration

of

the

system

using

radioactive

sources

Gain of the system

ENC Laser scans: Charge collection uniformity

Slide7

Already tested at IFIC

C. Mariñas, IFIC, CSIC-UVEG

Slide8

DEPFET Single-pixel (under construction)

D1

D2

S

G1

G2

Cl

Cl

Clg

Blk

Clg

C. Mariñas, IFIC, CSIC-UVEG

Inner

structure

Set-up

Better

understanding

of new

structures

Different

geometries

(L-

gate

)

Implants

Direct

access

to

the

system’s

parameters

Complete

clear

Charge

collection

Noise

Slide9

Test BeamC. Mariñas, IFIC, CSIC-UVEG

Slide10

Test Beam: Our roleC. Mariñas, IFIC, CSIC-UVEG

Full electrical characterization of one DUTParticipate

in the assembly

and allignment of the telescope

Parallel set-up in control room

Analysis of dataTest

Beam Coordinators 2008 and 2009 (

M.Vos)

BEAM

120 GeV

∏

x

y

z

Slide11

Test Beam: MeasurementsVoltage scans:

Cross-check optimal settingsVBias

to the

wafer 150-220VVEdge

VClearHighAngular

scan: Resolution vs. Cluster

size-5, -4, -3, -2, -1.5, -1, -0.5, 0, 0.5, 1, 1.5, 2, 3, 4, 5, 6, 9, 12, 18, 36

Beam energy scan: Separation “

multi-scattering-intrinsic resolution”

20, 40, 60, 80, 120 GeVLarge

statisticsCharge collection

uniformity3 Mevents in nominal conditions

C. Mariñas, IFIC, CSIC-UVEG

3.5 TB of data

20

Million

events

Slide12

T.B. Data analysisC. Mariñas, IFIC, CSIC-UVEG

d0 (32x24)

d1 (32x24)

d2 (24x24)

d3* (32x24)d4 (32x24)

d5 (32x24)Sig3x3(ADU)

1339

1497170417571508

1654

Noise (ADU)12,7

13,412,7

13,412,8

13,2

SNR

105

112

134

131

118

125

SeedSignal

(ADU)

69%

56%

59%61%63%64%ENC (e-)345326286277309290gq (pA/e-

)283

316360

372319

350

Preliminary

Seed

signal

Preliminary

Preliminary

Residual

(

s

MS

Ås

Tel

Ås

Int

,

m

m)

Beam

Energy

(

GeV

)

Distance

(

m

m)

Entries

s

total

=2,5

m

m

Slide13

Thermal studies: Simulation and measurementsC. Mariñas, IFIC, CSIC-UVEG

First

DEPFET

thermal

mock

-up

Thermal

simulation

Slide14

C. Mariñas, IFIC, CSIC-UVEG

Thermal

measurements

Influence of conduction

T of cooling

blocks Bump bonding

Influence of convection

Air speed

Air temperature Study

of new materials

Power

(W)

Temperature

(ºC)

Air

speed

(m/s)

Temperature

(ºC)

D

T

normalized

(K/mm2)Power (W)New materials

Slide15

C. Mariñas, IFIC, CSIC-UVEG

Thermal

simulation

Model implemented

in SolidWorks for

future mechanical studies ANSYS

studies calibrated

with real data

Slide16

A couple of movies…C. Mariñas, IFIC, CSIC-UVEG

Switching

mechanism

is

introduced

Influence

of air and liquid cooling studies

Slide17

ConclusionsVertexing in Future

CollidersVery hard conditionsRadiation

(10MRad for SuperBelle

)BackgroundReduced material

budgetUnprecedented granularity

Power consumption and

heat dissipation

Improvement of the detector’s performance is needed

New

generation of pixel detectors try to cope

with this requirements

DEPFET: One of the most

promising

technologies

for

vertexing

and tracking

C. Mariñas, IFIC, CSIC-UVEG

Slide18

Conclusions: DEPFET in ValenciaC. Mariñas, IFIC, CSIC-UVEG

Matrix

characterization

2

different

generations

characterizedFull electrical optimizationCalibration

Charge collection

uniformityWorking on

Single Pixel set-upTest BeamOptimization

of DUTInstalation and alignment of

the

telescope

Data

analysis

Thermal

studies

DEPFET

thermal

mock-upStudy of new materials

for better coolingInfluence of air/liquid coolingSimulation

Slide19

Backup slidesC. Mariñas, IFIC, CSIC-UVEG

Slide20

MechanicsSupport structures:

FEA models of mechanical propertiesNatural

frequenciesRigidity

StabilityDeformations

Validation with

mock-up

Module:

Simulations using FEA: (Finite Element

Analysis)Mechanical

effects: Strenght of module

Thermal effects: Cooling

Validation with prototypes

C. Mariñas, IFIC, CSIC-UVEG

Slide21

Competitors for SuperBelle

C. Mariñas, IFIC, CSIC-UVEG

DEPFET

Discarded

Material

Granularity

Slide22

Competitors for ILC

C. Mariñas, IFIC, CSIC-UVEG

Slide23

Double pixel structureC. Mariñas, IFIC, CSIC-UVEG

Slide24

Gain and noiseBa-133 (30keV g-ray

) → 310.4 ADC UnitsCd-109 (22keV g-ray) → 209.9 ADC

Units

E (

keV

)

ADU

22

30

310.4

209.9

FIT

y=a+bx

Slope

=

Gain

b=12.5 ADC/

keV

Noise

Gain

Energy

to

create

e

-

h

C. Mariñas, IFIC, CSIC-UVEG

Slide25

S/N for a MIP

1.- ATLAS supposition: 1 MIP

→22300 pairs e

-h in 285μm of Si

2.- Our DEPFET has 450

μm of Si

3.- The scale factor between Ba-133 30keV

g and a MIP is:

4.-

The

S/N of 30keV Ba-133 g ray scaled

to a MIP:

C. Mariñas, IFIC, CSIC-UVEG

Slide26

Noise in current

1.- ADC dynamic range: 2 V – 14 bits ->

2.- trans-impedance amplifier gain = 1 V / 50

m

A

3.- 15 ADC counts of noise

C. Mariñas, IFIC, CSIC-UVEG

Slide27

Introducing the deviceSwitchers A (Gate) and B (Clear) for CLG

A-GATE

B-CLEAR

CURO

C. Mariñas, IFIC, CSIC-UVEG

Slide28

CLG vs CCGVCleargate-Low

VCleargate-High

Amp

/

mV

Time/ms

V

Clear-High

V

Clear-Low

Clocked-Cleargate

V

Common-Cleargate

V

Clear-High

V

Clear-Low

Common-Cleargate

C. Mariñas, IFIC, CSIC-UVEG

Slide29

Effect on spectrum

#

Entries

ADU

Signal peak

Incomplete clear

Noise peak

Leackage Current

Background

C. Mariñas, IFIC, CSIC-UVEG

Slide30

AmplifiersOUT

IN

-5V

1.8V

1.3V

-3.2V

-8.2V

V

substr

39kΩ

I

in

AD8015

AD8129

5V

14V

+IN

-IN

REF

FB

>2V

2kΩ

18kΩ

6mV

R10

R10

R50

R50

150pF

7V

-7V

C. Mariñas, IFIC, CSIC-UVEG

Slide31

10V

C. Mariñas, IFIC, CSIC-UVEG

Slide32

C. Mariñas, IFIC, CSIC-UVEG

Slide33

Double pixel structure

Actual size of

two

pixels

Double pixel cell 33 x 47 µm

2

C. Mariñas, IFIC, CSIC-UVEG

Slide34

V

DRAIN

V

GATE

GND

55

Fe

Light

Pulsers

Sequencer

Shaper

ADC

PC

C. Mariñas, IFIC, CSIC-UVEG

Slide35

CDS

Correlated Double Sampling SchemeC. Mariñas, IFIC, CSIC-UVEG