CDC

S. Uno

KEK

2009.3.19

Endplate Design

sBelle

250mm300mm

350mm

3

Wire stringing • Strategy

– Vertically string wire – Outer cylinder is assembled before wire stringing.

– We can access wires from inside of chamber.– Nanae Taniguchi confirmed it with a hand-made mockup.

500mm30°

12°

710 mm

323 mm173 mm

Barrel PID

Present status of Super-belle CDC front-

end prototype.

KEK Electronics groupY. Igarashi ， K. Tauchi ， M.

Saito, M. Ikeno ， M. Tanaka ， Y. Uchida and

Takashi Taniguchi

CDC FE Prototype card

Under 20cm

ASB +Discriminator

ASB +Discriminator

ASB +Discriminator

ASB +Discriminator

FADC

• 16ch/board• BJT-ASB/Discriminator • FADC: over 20MHz / 10bit• FPGA : Vertex-5 LXT

– TDC: 1 nsec counting

– FADC reading

– Control

• FPGA: Spertan3A– SiTCP for CDC study

• Connectors– RJ-45 for SiTCP– RJ-45 for DAQ timing signals– RJ-45 for DAQ data line– SFP for DAQ data line– Optical TX/RX for GDL– LEMO input x 3, output x1

• Shielded substrate

FPGA(CONTROL,

TDC)R

J45

RJ4

5

SF

PO

ptic

al T

rans

ceiv

er

FADC

FPGA(SiTCP)

Opt

ical

Tra

nsce

iver

RJ4

5

Layout

• The printed circuit board is in process and will be available in next month.

Preamplifier and discriminator(8ch/card)

FADC

TDC

using FPGA

TDC in FPGA

• TDC in FPGA with time resolution of 1nS.– Make the TDC circuit to a library.

・ Input

ECL/LVDS/PECL 16 ｃｈ

CLK 、 START/STOP

・ Dynamic range 65us

・ 1ns/bit

・ FIFO 1023hit/ch

FPGA

4ns

Latch hit state and encode.

0

1

1

0

RMS=0.51ns

Input ： Hoshin 16bit TDC tester

TDC in FPGA 250MHz 4 phase Clock

for 1 nsec resolution.

AMP TEST with small tube chamber

and 5.9 keV X-ray

Nanae Taniguchi (KEK)

Mar. 18

11

Amplifier

• T-ASB– Used in trek/double beta experiment

• After pulse• Cross talk

• Hybrid ASB– Modify the T-ASB to be used super Belle-CDC

12

Setup

• Small tube chamber (tungsten wire)• 5.9 keV X-ray

• Gas(Ar90%+CH410%), P10 Gas

Gas (Ar 90%+CH4 10%) Fe55 5.9keV X-ray

Small tube chamber

ASB

Tungsten wire

13

Pulse shape

• Same HV (1.65kV)• Signal from Hybrid ASB is attenuated (15dB), current Belle AMP (6dB)

T-ASB Hybrid ASB

Different shaping time Over shoot disappeared

(smaller).Larger gain (~ x5)

Current Belle

14

T-ASB Hybrid ASBCurrent Belle AMP

Comparison of noise level

15

After pulse

HV=1.7kV HV=1.7kV

200ns/div 400ns/div

T-ASB Hybrid ASB

16

Cross talk

Ch 1Ch 16 Ch 15Ch 1

Ch 16

Ch 15

Cross talk is not so large.

Some discussion

• Material of end plate (CFRP)

• Gary’s proposal for readout electronics– We will discuss in next week.

• Diameter of wire

• Cluster counting method

Backup

CDC structure

Shoji Uno (KEK) 　　　

Dec-3rd, 2008

Baseline Design

Belle

sBelle

Main parameters Present Future

Radius of inner boundary (mm) 77 160Radius of outer boundary (mm) 880 1140Radius of inner most sense wire (mm) 88 172Radius of outer most sense wire (mm) 863 1120Number of layers 50 58Number of total sense wires 8400 15104Effective radius of dE/dx measurement (mm) 752 978Gas He-C2H6 He-C2H6

Diameter of sense wire (m) 30 30

1200 mm

250

mm

250

mm

Present CDC

New CDC

Wire Configuration

Small Cell Drift Chamber

Photo of small cell chamberPhoto of small cell chamber

Installation in 2003 summerJust after wire stringing

Curved Endplate• Deformation of endplate due to wire

tension was calculated at design stage of present Belle CDC (Total tension: 3.5 Ton).

Deformation(mm) 35.2 2.03 1.31

Present New

Weight

• Endplate 　– Al, Thickness : 10mm (12mm)– 110kgx2 = 220kg (264kg)

• Outer Cylinder – CRRP, Thickness : 5mm– 210kg

• Electronics Board– G10, 48ch/board– 0.3kgx315 = 95kg

Present support

Calculation of deformation and etc • Deformation of Aluminum endplate

– Thickness of endplate 10mm 　 12mm• Deformation 1/t3 1 0.58

– Tension of field wire 120g 80g• Gravitational sag, Sense : 120m(80g), Field:300m(80g)• Total tension 4.8ton 　 　　　

• Stress calculation – Thickness of outer cylinder CFRP ： mm 　– Transition structure between endplate and outer

cylinder

• Support structure• Structure for wiring jig

– Simpler one as compared with Belle-CDC

• Etc.

Wire stringing • Now, I am thinking a vertical stringing, not

horizontal. – Once, I thought the horizontal stringing

• Vertical stringing with outer cylinder.– Human can stand inside the chamber and can

touch the wire. • Inner diameter without the small cell part : ~500mm • Inner diameter of present transition cylinder :

580mm

– Stringing with tension can be done from outer layer.

• Two-way method ( Belle-CDC ) is not necessary.

Installation

• Removing and installation can be done using similar small bar in horizontal direction.

Cathode installation in vertical direction CDC installation in horizontal direction

My Personal Plan for Construction

FADCTi

ADS5287

ASBDiscriminator

SFP(Optical connector)

RJ-45

LVDS8 pairs

CONTROL 3x4

Vertex-5 LXT(XC5VLX50T, IO:360pin)

LVDS 2 pairs

LVDS 4 pairs

RJ-4515

TIMING LVDS 4x4 pairs

LEMO

LEMO

LEMO

LEMO

RocketIOGFP

100basePHY

Spertan3ASiTCP

TDC(with FIFO)

3

FIFO

4 LEDDIP-SW8

16

16

TEST PIN16

CONTROL

CLK125MHz

Sampling CLK20~40 MHz

CLK42.33MHz

ASBDiscriminator

FADCTi

ADS5287

ASBDiscriminator

ASBDiscriminator

De-

seria

lizer5

LVDS8 pairs

5

48

DIP-SW

TEST PIN8

32

CLK50MHz

LVDSCLKs

LVDSCLKs

PUSHSW

DAC(Vth)

8

RocketIOGFP Optical connector

LVDS 2 pairs

CLKFor GFP

RocketIOGFP RJ-45LVDS 2 pairs

LOGIC part diagram

Front-end(preamp)

• 7mm□ ．• 48pin.• ASB.• Gain SW.• 1/t tail

cancellation.

Front-end (for the system test)

• ASB– Amp. Shaper Buffer– 4ch/chip– Peaking time ~ ４０ nsec– Gain :

• -360mV/pC ~ -1400mV/pC

• (4 step variable)

ASB

protection

Disc.

Fe source

D-out

A-out

Hybrid preamp• Common

emitter amp.

• 3 stage amplification.