Study of the Central Tracker for Huge Detector at the Linear Collider Takashi Watanabe Kogakuin University The 7th ACFA Workshop on Physics & Detector

Study of the Central Trackerfor Huge Detectorat the Linear Collider

Takashi WatanabeKogakuin University

The 7th ACFA Workshopon Physics & Detector at the Linear Collider

9-12 November 2004, Taipei, Taiwan

The 7th ACFA Workshop on Physics & Detector at the Linear Collider Takashi Watanabe (Kogakuin University)

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Contents

Physics RequirementsTPC study with MPI TPC (MWPC)

Beam test w/o Magnetic FieldCosmic-ray test w/o Magnetic Field

GEM performanceSummary


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Europe/Asia TPC collaboration Europe

MPI DESY IPN Orsay

Asia Chiba University KEK

Kinki University Kogakuin University Mindanao State Univeristy Saga University Tokyo University of Agricultur

e and Technorogy University of Tokyo University of Tsukuba


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Conclusions of Last workshopMost of R&D questions in Proof of

Principle phase have been answered affirmatively. This means that original R&D goals are basically achieved.

Next phase is engineering design, which requires a full scale prototype test.

orWe will seek for other possibilities .(e.g. TPC)


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Present Situation ITRP recommends “Cold” Technology

(August, 2004)Basically, requirements for Huge

detector from physics are almost same.

Requirement for Main Tracker

Good recoil mass resolutionGood jet invariant mass resolutionTime stamping


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Recoil Mass Resolution


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Jet Invariant Mass Resolution

Good track-cluster matchingz 1mm

2-track separationbetter than 2mm

< 10% hit loss at inner most layer for 250GeV W’s

not mentioned in this talk


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Time Stamping CapabilityTESLA NLC

Repetition rate 5Hz 120Hz

Bunches per train 2820 192

Bunch separation 337ns 1.4ns

Train-length 950s 260ns

Train separation 199ms 8.3ms

TESLA NLC

Repetition rate 5Hz 120Hz

Bunches per train 2820 192

Bunch separation 337ns 1.4ns

Train-length 950s 260ns

Train separation 199ms 8.3ms


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Present Situation ITRP recommends “Cold” Technology

(August, 2004)Basically, requirements for Huge

detector from physics are almost same.

Requirement for Main Tracker

Good recoil mass resolutionGood jet invariant mass resolutionTime stamping


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Position Resolution

TPC with micro pattern readout


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TPC R&D item

Dispersion of charge cloud strongly depends on B-fields & drift length

Beam test with Magnetic field

MPGD sensor must provide better performance than wires do,

but…We should define base line sensor for TPC using MWPC (for fallback option?)

2mm spacing with 1mm gap to cathodesExB effect should be smallerLocalize induced charge distribution on pads


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JACCEE magnet (for BESS-II)

No Return Yoke B = 1~1.2T @ center


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PS beam line @ KEK PS

East Counter Hall

E391a experiment

(KL →0)

2 line0.6-4GeV/c

p

about 20m

a few percent effect of magnetic field

Magnet excitation was limited only one time


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beam line

TPC in JACCEE magnet

Beam


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Detachable endplateMWPCMPGD (GEM, MEGAS)

2.00mm x 6.00mm readout pads32pads x 12 rows

7padrows equipped2mm anode-wire spacing

Small wire angular (ExB) effectMaximal drift length: 270mm1atm Ar:CH4:CO2 (93:5:2) TDR gas

Vdrift = 45mm/s (Edrift=200V/cm)

MPI TPC

Field Cage (Vcathod=6kV)

wire

chargepad

1mm


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JACCEE magnet

No Return Yoke B = 1~1.2T @ center


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Electronics

ALEPH based readout electronicsFASTBUS FADC: 80ns time slotPre-amplifier: 500ns shaping time


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Typical Event

B = 1Tp = 4GeV/c = 20deg


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Pad Response Function

Xpad-Xtrack 　 (mm)

Normalized Qi1

0

Slice on x axis obtain the mean fit themWith Gaussian to get width

B = 0TAlong z every 10mm

by Kijima


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Parameterization of PRF

consistent

by Kijima


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x as a function of drift distancepreliminary

not calibratednot corrected

Ne~25!?

by Ikematsu


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x as a function of drift distance

CD~0.1mm/sqrt{cm} @ B=3T (D.Karlen’s Cal.&Mes.)

x ~ 280m @ 2000mm evenif geom=0m

Do calibration and correction Needs gas study Study why Ne is small (charge screening?)


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z as a function of drift distancepreliminary

z<800m for all drift region

not calibratednot corrected

by Ikematsu


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Wire Angular (ExB) Eff.x as a function of track-wire angle w/ B-field 1T

by Ikematsu


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Next StepCosmic-ray test at the KEK Cryogenic

Center


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Cosmic-ray test @ the KEK CC

Superconducting magnetwith return yoke


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Next StepCosmic-ray test at the KEK Cryogenic

CenterMWPC (now suspended because of DAQ

problems)4 layers GEM (from December?)


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GEM

bi-conical holes due to chemical etching( CERN, 3M ) Copper electrodes 5um thick Kapton insulator

CNS@Tokyo univ. + Fuchigami Micro Co. using Plasma etching -> straight holes

Need Comparison under realistic operation condition !!


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CERN GEM & Fuchigami GEM

CERN GEM dark ring around hole

shows Kapton insulator

Fuchigami GEM straight hall

Photos by microscope


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GEM readout


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GEM beam testSame time with MPI-TPC w/ MWPCNo Magnetic FieldP-10 gas

Test Chamber


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Setup

23.5mm

1.5mm

1.5mm • VG-G = 2kV/cm

• VG-P = 3kV/cm

Drift region

GEM10M

10M VGEM

10,30,50M

1mm

Readout pads(same with MPI-TPC)


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PRF of GEMElectrons from

track (around center of pad) went to only one pad

2mm is too

large?

Nor

mar

ized

Q

xpadxtrack

Pad Response Function

by Sakamoto


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Next StepCosmic-ray test at the KEK Cryogenic Center

MWPC (now suspended because of DAQ problems)

4 layers GEM (from December?)Beam test at the KEK-PS Counter Hall

(April/May, 2005?)4 layers GEMMEGAS

Cosmic-ray test with new readout(summer 2005?)


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Summary

We joined the world TPC club and studied the basic line using MPI-TPC w/ MWPC.

We have a lot of study items for TPC w/ MPGD (but we have no enough time).

We are always waiting your comments and joining to our group.

Documents

Study of the Central Tracker for Huge Detector at the Linear Collider Takashi Watanabe Kogakuin University The 7th ACFA Workshop on Physics & Detector