GEM を用いた大アクセプタンス検出器に用いる

読み出し回路の開発東大・理　小沢　恭一郎

検討

Example: E16 Detector

2010/06/04 K. Ozawa 2

Tracker~100μm の分解能ハイレートへの耐性 (5kHz/mm2)少ない物質量(1 チャンバーにつき ~0.1% )

Electron identificationLarge acceptanceHigh pion rejection @ 90% e-eff.

100 @ Gas Cherenkov25 @ EMCal

Items

2010/06/04 K. Ozawa 3

Develop 1 detector unit and make 26 units.

Hadron Blind detectorGas Cherenkov for e-ID

GEM Tracker

Ionization (Drift gap)+ Multiplication (GEM)

High rate capability + 2D strip readout

CsI + GEMphoto-cathode

50cm gas(CF4) radiator~ 32 p.e. expected

CF4 also for multiplication in GEM

GEM Tracker

2010/06/04 4

Collaboration with KEK

K. Ozawa

700 mm pitch (350 mm x 2) for both side

Gas: p10 or Ar/CO2Currently, p10 gas is used due to a large diffusion.

Easy signal handlingPulse shape

2010/06/04 K. Ozawa 5

Signal from Readout pad

Signal from GEM foil

80ns

150mV

GEM Response function

Time constant is from the drift time in the last gap. (No ion tail)

It can be reduced to ~20ns.

σ ＝ 181.2±0.3 μmAr-CO2 (70/30)

Width of signal spread is consistent with transverse diffusion in GEM (along 3layers ).

No magnetic Field/ No Drift regionσ ＝ 359.7±0.4 μmP10

Response function

Prof. S. Uno @ MPGD WS

Read out configuration

2010/06/04 K. Ozawa 6

Detector outInitial Charge ~ 100eGEM gain ~ 104

Capacitance: Strip

Front-end:Charge-sensitive preamplifier

Ci ~ 1pFShaper

Digitize:ChargeTimingTime Spread

ASIC

FPGA BoardDepends on each experiment

7

Front-End Electronics: Candidate 1• Originally, it’s developed for CMS Si detector.• Also, it’s used for COMPASS GEM

APV-S1 chip

2010/06/04 K. Ozawa

K. Ozawa 82010/06/04

Candidate 2: Fusayasu chipProf. T. Fusayasu @ IEEE/NSS

Made by T. Fusayasu for GEM x-ray detector (strip readout)

– 8 chs./package– Input range 　 50fC ～ 1pC– 10MHz-10bit ADC and 100MHz-10bit TDC– Operating voltage 　 ±2.5V – Power 　 50mW/ch– noise 15000e @Cd=50pF

9

Front End ASIC by KEK• Front end ASIC for gas detector

– Developed by KEK 　 Dr. Fujita• Specification

– Amp. ,shaper, discriminator– 8 chs./package– Output 　 8 LVDS, 1 analog-sum– Operating voltage 　 ±2.5V – Power 　 30mW/ch– Input range 　 -1.5pC ～ +1.5pC– noise 6000e @Cd=100pFFE200X

Dr. T. Uchida@ MPGD WS

2010/06/04 K. OzawaNot including ADC, Just 1 bit information per channel

10

ILC R&D• Pre-amp/Shaper chip:

– 16 chan/chip*8chips/card=128chan/card– Gain & shaping time adjustable– 400 e’s noise in reasonably large system

• Digitizer based upon ALTRO chip:– 10 bit 20 MHz ADC– 1k sample storage

• In Japan,– A. Sugiyama (Saga University)– T. Fusayasu (Nagasaki Institute of Applied Science )

• In addition, they are developing a pixel readout chip. QPIX: 100mm pixel, 0.5p max inputs, 14 bits ADC, 10ns timing resolution

2009/9/12 K. Ozawa

QPIX

234

56

7

200 mm

1 : 6b-SAR ADC2 : OP Amp3 : Comparator4 : 14b-Register5 : 8b-ToT Counter6 : Control Logic7 : 14b-ToF Register8 : MIM Cap (2p)

140 mm8

Chip area can be reduced to 100um x 100umby further circuit optimization.

1

0.18um CMOS100 mm

100

mm

Furtheroptimization

2010/06/04 11K. Ozawa

Prof. A. Matsuzawa (TIT)

Performance table

2010/06/04 K. Ozawa 12

QPIX.v.1 QPIX v.0 Timepix

Dimensions 100x 100μm2 140 x 200μm2 50 x 50μm2

Preamp Gain 0.5-5mV/fC 0.45mV/fC 100mV/fC

Comparator threshold 1-10fC 10 fC 0.1 fC

ADC LSB/MSB 8fC/0.5pC 26fC/1.6pC -

Readout information TOF: 14bits TOF: 14bits 14bits(TOF or TOT or

counter)TOT: 8bits TOT: 8bits

ADC: 6bit, 10Msps

ADC: 6bit10Msps

None

Power 30uW 350uW (80uW) 6.5uW

Read out Parallel Parallel Serial/Parallel

NowEnd of ‘09

Prof. A. Matsuzawa (TIT)

Hadron Blind Detector

• 紫外域に感度を持つ CsI 光電面– Cherenkov 光検出に最適– GEM 上面に CsI 光電面を蒸着

– 100 mm GEM を用いる• Radiator ガス : CF4

– High transmission @ UV

2010/06/04 13

CsI 光電面による Cherenkov 光検出器

MESH

2 mm

1.5 mm

3.25 mm

5.25 mm

LCP(100um)

CsI

pad

Cere

nkov

phot

on

Ionization(40)

Phot

oelec

tron (

32)

50umGEM50umGEM

32 x 800

– p Threshold 4 GeV/c • GEM ３層を電子増幅に使用

– Gain ~ 800 @ CsI GEM Important for e/p

• Pad 読み出しで位置情報も

• 逆電圧による電離電子の抑制 !!

Ref. NIM A523, 345, 2004

ElectronCF4 Radiator

By K. AokiK. Ozawa

Read out configuration

2010/06/04 K. Ozawa 14

Detector outInitial Charge ~ a few eGEM gain ~ 104

Capacitance:Large Pad

Front-end:Charge-sensitive preamplifier

Ci ~ 1pFShaper

Digitize:ChargeTimingTime Spread

Preamp-CardFPGA Boardcommercial FADC

K. Ozawa 15

PHENIX Pre Amplifier

2010/06/04

Features:1) +/- 5V power supply.

2) 165 mW power dissipation.

3) Bipolar operation (Q_input = +/- )

4) Differential outputs for driving 100 ohm twisted pair cable.

5) Large output voltage swing -- +/- 1.5V (cable terminated at both ends)

(+/- 3V at driver output)

6) Low noise: Q_noise = 345e (C_external = 5pF, shaping = .25us)

(Cf = 1pF, Rf = 1meg)

7) Size = 1.04” x 0.775” 10pins

8) Preamp output (internal) will operate +/- 2.5V to handle large pile-up.

Charge Preamp with On-Board Cable Driver

Preamp (BNL IO-1195)2304 channels total

19 mm

15 mm

K. Ozawa 162010/06/04

IO1195-1-REVA

K. Ozawa 172010/06/04

ADC Data: Fe 55 Pulse Height Spectrum in pure CF4(IO1195 PreAmp)

0

10

20

30

40

50

60

70

0 43 86 129

172

215

258

301

344

387

430

473

516

559

602

645

688

731

774

817

860

903

946

989

ADC Ch.

Cou

nts

Gain ~ 1700FWHM % Res~38%

Test with GEM DetectorPA Pulse Trace on Scope

PA Pulse Height Spectrum

Pulser Input (1.2pF)~ 13mV100,000 e-’s

s (Baseline Noise) ~1100 e-’s

•Input capacitance ~ 0.0 pF?? •20 pe x 5E3 (gain) ~ 100,000 electron input intopre-amp• Baseline Noise~ 1100e-’safter background is subtracted off.

PA Output~48mV

B.Azmoun

2010/06/04 K. Ozawa

Connector

Differential Receiver 8

Channels65 MHz12 bits

ADC

FPGAReceive/buffer

ADC data

Format triggered Events

Generate L1 Primitives

Receive timing/clocks

Datapath

interface FEMFEM FEM FEM Optical

GTM/Ethernet Detector signals DCM

Trigger data

FEM Block Diagram

FEM Crate Diagram

LL1 trigger

18

K. Ozawa 192010/06/04

The 8 channel 12 bits 65MHzADC

The ADC receives differential signalsThe Vcommon is 1.5VThe +/- input can swing from 1V to 2V

+ side 2V, - side 1V -> highest count- side 2V, + side 1V -> lowest count

Our +/- input will swing from 1.5 to 2V/ 1 to 1.5V

we will only get 11 bits out of 12 bits16fc will be roughly sitting 200 count

We will run the ADC at 6X beam crossing clock6X9.4 MHz = 56.4 MHz or ~17.7ns per samples

TI ADS5272

Cost: $25 per channel

Signal cableinput

Trigger output

HBD FEM

Clock input

2010/06/04 20K. Ozawa

まとめ• E16 実験のための検出器開発が、理研、東大などで

活発に行われている。読み出し回路の開発はこれから。

• High Beam intensity と大立体角測定に対応するため GEM Tracker を使用する。– 読み出しは、ストリップ– Front-end は集積度を上げる必要がある。

• 大立体角で電子識別を行うために、 CsI + GEM を光電面に用いたチェレンコフ光検出器 (Hadron Blind Detector) を使用する。– 平均 20p.e. 程度しか期待できないため、 low noise は必

須– そのあとは出来るだけ安く上げたい。

2010/06/04 K. Ozawa 21

BACK UP

2010/06/04 K. Ozawa 22

Good @ high rate counting• MWPC limitation

– Wire spacing: 1~2 mm– Gain dropping @ high rate

• Micro strip gas chamber – Discharge problem

• Micromegas– Another candidate

• GEM– Flat gain over 105 Hz/mm2

– I like flexibility of configuration– Good characteristics of signal

• Signal is generated by electron • Not by ion• No ion tail and pole cancellation

electronics

2010/06/04 K. Ozawa 23

GEM

MWPC

104 105

I took these ideas and figures from F. Sauli’s presentation at XIV GIORNATE DI STUDIO SUI RIVELATORI Villa Gualino 10-13 Febbraio 2004

104 105

K. Ozawa 242010/06/04

Frontend OP ampStandard Folded-Cascode OP amp

DC Open loop gain 64.2dB

gain band width 63.1MHz

phase margin 77.4°

Common-mode gain -16.7dB

Common-mode rejection ratio 80.4dB

PSRR+ 70.1dB

PSRR- 84.1dB

output impedance 414kΩ

slew rate 148V/us

settling time 　 (1%) 26.1ns

OP amp feature obtainedby schematic simulation

K. Ozawa 252010/06/04

Test Charge Measurement

Deviation from Linear Slope

-10

-5

0

5

10

15

20

25

0 200 400 600 800 1000

Qin [fC]

AD

C c

ount

Dev

iatio

n [L

SB

]

ADC~~

~

1pF1pF

-+

GEMFE2ch0

100ns

Test Pulse

Good linearity was obtained at 1MHz ADC operation except for lower and upper edge of the range.

ADC count vs. Input Charge

0

200

400

600

800

1000

1200

0 200 400 600 800 1000

Qin [fC]

AD

C c

ount

[LS

B]

VT=40mV

K. Ozawa 262010/06/04

Noise MeasurementNoise Properties of GEMFE2

0

5000

10000

15000

20000

25000

30000

0 20 40 60 80 100 120

Detector Capacitance [pF]

EN

C [E

lect

rons

]

MCLK=1MHzMCLK=2MHz

10k electrons @ Cd=0pF (15k@50pF) Enough for our purpose.

CSI を用いた光電面• 3 種類の光電子収集の方法

2010/06/04 K. Ozawa

TransmissiveBy Weitzman • Transmissive を選択

– 比較的高い量子効率– 少ない photon feedback

一番上の GEM に CSI を蒸着して実現

CSI の量子効率５ １０ １５

[eV]27

HBD FEE• 48 channels per FEM

– 3 signal cables to detector.– 4 signal pairs to HBD LL1 crate – within the racks– Clock cable from interface to the FEM – within the crates (back)– 6UX160mm card size

• Interface module – GTM (clock, L1 trigger etc.), Ethernet interface for slow download.– Control test pulse – don’t know the cable size yet.

• Data output module– 1 optical module per card

• Crate has– 16 FEMs– 4 optical output modules– 1 interface module

• HBD readout will fit into 3 6U crates• HBD LL1 module potentially could fit into one 6U crate.• Power – 5V digital, +4 analog, -3.3V analog – 1KW per crate (?)• We will use a standard VME 6U crate mechanics with custom backplane.

– We will bring the crates. • Need space to route the signal cables to the FEM

– Need to know how long is the cable routing path- Signal cables are custom made

2010/06/04 28K. Ozawa

K. Ozawa 292010/06/04

S- S+ G S+ S-

Signal arrangement

Use 2MM Hard Metric cable to move signals between preamp/FEM2mm HM connector has 5 pins per row and 2mm spacing between pins and rowsThere are two types of cable configuration: *100 ohms parallel shielded cable

50 ohms coaxial cable

Our choice is This gives us signal density 2mm x 10mm for every 2 signals.Same type of cables will be used for L1 trigger data.

K. Ozawa 302010/06/04

The differential receiverUse Analog Device

AD8138 receiverset up as unity

gain

Total voltageOn the cable

Total voltage Seen by ADC

Simulation resultFor 16fc input charge

ADC +/- inputsADC has 1V rangeMax ADC range is about ~10 time of 16fc