1. Result of MWPC-TPC beam test ILC Detector Workshop 3-5 March 2005, KEK Osamu Nitoh, TUAT

2. 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

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

4. MPI-TPC prototype

5. 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

6. e B E Pad plane(10×10cm) 36cm 27cm ～ 200V/cm TPC Cage Gas Ar:CH 4 :CO 2 93:5:2 Maximum drift length 27cm Cross section of TPC

7. JACEE magnet (for BESS-II) Without Return Yoke B =1~1.2T @ center

8. C1 C2 Aeroge l TC1TC2 TOF1 TOF2 TPC 7m π ２ beam line

9. π2 beam line Beam TPC in JACEE magnet

10. TPC Setup into Magnet

11. Typical Event π - B = 1T p = 4GeV/c φ = -20deg

12. Pad Response Function X track -X padi (mm) Q i /Q total Wire Pad X padi X track 1 0 Drift track

13. B=0T 0-10 210-220 160-170 110-120 60-7050-60 100-110 150-160 200-210230-240 70-80 220-230 120-130 170-180180-190 90-100 240-250 190-200 140-150 80-90 130-140 10-2020-3030-4040-50 Drift distance : z=0-10,10-20,20-30,....,230-240,240-250mm B=1T

14. Drift distance: z=0-10,10-20,20-30,....,230-240,240-250mm 0-10 210-220 160-170 110-120 60-7050-60 100-110 150-160 200-210230-240 70-80 220-230 120-130 170-180180-190 90-100 240-250 190-200 140-150 80-90 130-140 10-2020-3030-4040-50

15. Drift distance dependence {σ x (z=0)} 2 2.06±0.01 D C 2 0.005±0.00009 {σ x (z=0)} 2 2.07±0.02 D C 2 0.025±0.0002 B=0T B=1T σx２σx２

16. Diffusion Constant σ x (z= 0)=1.4(mm) B=0T: C D =0.5mm/√(cm), B=1T: C D =0.22mm/√(cm)

17. Φdependence （ B=1T,z=0 ) σ 2 PRF =σ 2 PRF (min)+b 2 （ tanφ-tan(ψ eff )) 2 σ PRF (min) 1.432±0.004 b 2.3±0.08 tan(ψ eff ) 0.02852±0.008 2.85 2.05

18.  z as a function of drift distance preliminary

19. Charge Distribution( 1 Hit) Q i 1GeV π 2GeV π 4GeV π 1GeV P 2GeV P 4GeV P

20. 1GeV P 2GeV P 4GeV P 1GeV π 2GeV π 4GeV π Charge Distribution( １ Track) Average over 1 tack (Sample length 6mm×7pad-rows) ΣQ i ７ I=1 7 Q 7 =

21. dE/dX resolution (MPI-TPC ) ＞ 5/7 Trancated Mean P 4GeV ＞ βγ Dependence ΣQ i 7 I=1 7 Q 7 = ΣQ i 5 I=1 5 Q 5/7 = ( Q i = smallest 5 in 7) Search the dependence by using the Q 5/7

22. dE/dX Resolution Mean =216.8 σ = 46.9 σ = 46.9 Mean =194.1 σ = 51.7 σ = 51.7 π P σ ÷<Mean> = 21.6±0.8% = 21.6±0.8% σ dE/dx = 4GeV 4GeV σ dE/dX = 26.6±1.5%

23. * Extrapolation to the LC TPC ＊ 70%Trancated Mean π 4GeV Assume LC TPC with Rout - Rin (= 160cm) ＊ 175sample 250samples = (Rout - Rin) / l pad =(1600mm / 6.3mm) Q i (I=1,,,, 250) Q i (I=1,,,,175) Smallest 70% ΣQ i 175 I=1 175 Q 175 =

24. dE/dX Resolution ４ GeV Proton = 180.9 = 180.9 rms = 7.7 rms = 7.7 ４ GeV Pion = 203.8 = 203.8 rms = 7.3 σ dE/dX = 3.6±0.7% π P 4GeV σ dE/dX = 4.2±0.8% ΣQ i 175 i=1 175 Q 175 = ( Q i =smallest 175 in 250)