1. TPC R&D status in Japan T. Isobe, H. Hamagaki, K. Ozawa, and M. Inuzuka Center for Nuclear Study, University of Tokyo Contents 1.Development of a prototype TPC 2.Basic Gas Test of pure CF4 3.Performance evaluation 4.GEM development 19, Nov., 2003TPC/HBD Upgrade Working Group Meeting

2. Development of a prototype TPC A prototype TPC –30cm drift length, -30 kV HV –Readout from cathode pads  20  m anode wire 13mm, 9.5mm, 6mm, 2.5mm pad Designed as GEM can be mounted –Three holes for LASER input Front End Electronics Charge sensitive Pre-amp –300MHz bandwidth 100MHz 8bit FADC Drift 34cm -V Readout Drift region

3. Gain Gain test setup 6*10^4 5.9 keV X-ray from 55 Fe  CF4 needs much higher voltage to detect the suitable signals.

4. CF 4 characteristics Drift velocity and longitudinal diffusion were measured. –N 2 LASER (λ=337nm) Attenuated for single electron source Input to 3 different positions Gas condition 20  C,1 atm H 2 O = 100ppm O 2 = 30ppm Test system 10cm/μsec @900V/cm/atm 60μm

5. Performance of TPC Energy loss Schematic view of the beam test setup Beam Test at KEK(Jun. 2003) –e,π,p,d beam (0.5-2.0GeV/c ) –readout with anode wire (no GEM readout) Measurement Topics –Position resolution 100μm resolution along the anode wire direction (2.5mm pad) 500μm resolution in the drift direction –Double Track Separation Double track could be identified, when the difference in distance between the tracks in the drift direction was more than 1.5cm –Particle Identification Estimate that it is able to identify the electron with p < 80MeV/c –5cm track length, 2  separation

6. Development of GEM Two kinds of GEM are tested –GEM from CERN Sauli group Wet etching 100 GΏ between both electrodes –GEM was made in Japan Univ. of Tokyo and Fuchigami Co. Plasma etching 10 GΏ between both electrodes CERN Fuchigami CO. Gain *10^3 [V] P10 Ar-CO2 consistent with the results of CERN GEM Next  Plan to test GEM readout for TPC

7. Summary & Outlook Achievements –A prototype TPC was developed. –CF 4 characteristics was investigated. 10cm/μsec drift velocity & 60μm longitudinal diffusion @E=900V/cm –Total performance of TPC with CF 4 gas was investigated. achieved 100μm resolution along the wire direction –GEM was developed using plasma etching method in Japan. Outlook –Install the GEM as TPC readout investigate the capability (next year) –Other types of readout pads –Improve the Front End Electronics Applying for the high density signal (large band width)

8. Additional slides

9. CF4 signal 110n second rise time ~10 points to obtain the T0. –With 100MHz sampling

10. Position Resolution Position resolution in the drift direction and along the anode wire were investigated as a function of drift length, pad size and input angle. 100μm

11. Beam Test(2) Drift direction Along the wire 100μm 500μm Position resolution 80MeV Double Track Energy loss