result of mwpc-tpc beam test

Result of MWPC-TPC beam test

ILC Detector Workshop 3-5 March 2005, KEK

Osamu Nitoh, TUAT

collaboration Europe

DESY MPI IPN Olsay

Asia KEK Kinki University Kogakuin University Saga University Tokyo University of Agriculture and Technology University of Tokyo University of Tsukuba Mindanao State University

MPI-TPC prototype with MWPC replaceable with GEM, Micromegas,

MPI-TPC prototype

Pad plane

Pad plane 100mm x 100mm Pad size 2mm x 6mm 12 of 16 rows (384 pads) Wire spacing 2mm (without field wires) Pad-wire distance 1mm (σ_PRF ~ 1.4mm, in principle)

Ｙ

Ｘ

e

BE

Pad plane(10×10cm)

36cm

27cm

～ 200V/cm

TPC Cage

Gas 　Ar:CH4:CO2

93:5:2Maximum

drift length27cm

Cross section of TPC

JACEE magnet (for BESS-II)

Without Return Yoke

B =1~1.2T @ center

C1 C2 Aerogel

TC1 TC2TOF1 TOF2

TPC

7m

π ２ beam line

π2 beam line

Beam

TPC in JACEE magnet

TPC Setup into Magnet

Typical Event

π-B = 1Tp = 4GeV/cφ = -20deg

Pad Response Function

Xtrack-Xpadi 　 (mm)

Qi/Qtotal

Wire

Pad

Xpadi

Xtrack

1

0

Drifttrack

B=0T

0-10

210-220

160-170

110-120

60-7050-60

100-110

150-160

200-210 230-240

70-80

220-230

120-130

170-180 180-190

90-100

240-250

190-200

140-150

80-90

130-140

10-20 20-30 30-40 40-50

Drift distance : z=0-10,10-20,20-30, .... ,230-240,240-250mm

B=1T

B=1TDrift distance: z=0-10,10-20,20-30, .... ,230-240,240-250mm

0-10

210-220

160-170

110-120

60-7050-60

100-110

150-160

200-210 230-240

70-80

220-230

120-130

170-180 180-190

90-100

240-250

190-200

140-150

80-90

130-140

10-20 20-30 30-40 40-50

Drift distance dependence

{σx(z=0)}2 2.06±0.01

DC 2

0.005±0.00009

{σx(z=0)}2 2.07±0.02

DC2

　　 0.025±0.0002

B=0T

B=1T

σx２

Diffusion Constant

σx(z=0)=1.4(mm)

B=0T: CD=0.5mm/√(cm), B=1T: CD=0.22mm/√(cm)

Φdependence （ B=1T,z=0)

σ2PRF=σ2

PRF(min)+b2 （ tanφ-tan(ψeff))2

σPRF(min) 1.432±0.004 b 2.3±0.08tan(ψeff) 0.02852±0.008

2.85

　 2.05

z as a function of drift distance

preliminary

Charge Distribution( 1 Hit) Qi

1GeVπ

2GeVπ

4GeVπ

1GeVP

2GeVP

4GeVP

1GeVP

2GeVP

4GeVP

1GeVπ

2GeVπ

4GeVπ

Charge Distribution( １ Track)Average over 1 tack (Sample length 6mm×7pad-rows)

ΣQi

７

I=1

7Q7 =

dE/dX resolution (MPI-TPC)＞ 5/7 Trancated Mean

　P 4GeV

＞ βγ Dependence 　　　

ΣQi

7

I=1

7Q7 =

ΣQi

5

I=1

5Q5/7 =

( Qi = smallest 5 in 7)

Search the dependence by using the Q5/7

dE/dX Resolution

Mean =216.8Mean =216.8　　　　 σ = 46.9σ = 46.9

Mean =194.1Mean =194.1 σ = 51.7σ = 51.7

ππ

PP

σσ ÷<Mean>÷<Mean>

= = 21.6±0.821.6±0.8%%σσdE/dxdE/dx

==

4GeV4GeV

4GeV4GeV

σσdE/dX dE/dX = = 26.6±1.526.6±1.5%%

*Extrapolation to the LC TPC

＊ 70%Trancated Mean

　 π 4GeV

Assume LC TPC with Rout - Rin (= 160cm)

＊ 175sample

250samples

= (Rout - Rin) / lpad

=(1600mm / 6.3mm)

Qi(I=1, , , , 250)

Qi(I=1,,,,175)Smallest 70%

ΣQi

175

I=1

175Q175 =

　 dE/dX Resolution

４４ GeV ProtonGeV Proton <dE/dx>=<dE/dx>= 　　 180.9180.9

rmsrms 　　 = 7.7 = 7.7

４４ GeV PionGeV Pion <dE/dX>= 203.8 <dE/dX>= 203.8

rmsrms 　　 = 7.3= 7.3

σσ dE/dXdE/dX = = 3.6±0.73.6±0.7% %

π

P

4GeV

4GeV

σσdE/dXdE/dX == 4.2±0.84.2±0.8%%

ΣQΣQii

175175

i=1i=1

175175QQ175175 = = ( Q( Qi i ==smallest 175 in 250)smallest 175 in 250)