1. Wenxin Wang (D. Attié, P. Colas, E. Delagnes, Yuanning Gao, Bitao Hu, Bo Li, Yulan Li, M. Riallot, Xiaodong Zhang)

2.  Came from Lanzhou University  PhD thesis in Orsay University  Work in RD51 (advisor P. Colas) “ Study of large Micromegas detectors for calorimetry and muon detection ” Self-Introduction Lyon, 09/04/2010W. Wang - FCPPL workshop 1 1.2×0.4m 2 Micromegas prototype Micromegas Digital HCAL

3. I.ILC-TPC 1.1 Micromegas ILC-TPC:  ILC-TPC Large Prototype  Bulk Micromegas with resistive anodes  T2K electronics  Data analysis results 1.2 Tsinghua GEM-TPC improvement (TU-TPC) II. Fast Neutron Imaging Micromegas Detector Outline Lyon, 09/04/2010W. Wang - FCPPL workshop 2

4. I.ILC-TPC 1.1 Micromegas ILC-TPC Lyon, 09/04/2010W. Wang - FCPPL workshop 3

5. 4 metallic micromesh (typical pitch 50μm) sustained by 50-100 μm pillars (<100 μmSpatial resolution (<100 μm ) few nsTime resolution (few ns) High-rate capability Good robustness Amplification gap ~50-100 µm ~50 kV/cm cathode Drift gap ~0.3 kV/cm Micromegas Lyon, 09/04/2010W. Wang - FCPPL workshop Y. Giomataris, Ph. Rebourgeard, JP Robert and G. Charpak, NIM A 376 (1996) 29 E drift / E amplif ~ 1/200 MICROMEsh GAseous Structure

6. 5 E Ionizing Particle electrons are separated from ions electrons diffuse and drift due to the E-field Localization in time and position B x y A magnetic field reduces electron diffusion Micromegas TPC : the amplification is made by Micromegas Micromegas TPC: Time Projection Chamber Lyon, 09/04/2010W. Wang - FCPPL workshop t Ionization energy loss(dE/dx) 3D track points reconstruction

7. Design for an ILD TPC in progress 2x80 modules with 8000 pads each 6 ILC-TPC Large Prototype Lyon, 09/04/2010W. Wang - FCPPL workshop Goal: O(200) track points transverse resolution : 100 μ m (2 m drift & 3.5 T magnet).

8. Built by the collaboration Financed by EUDET Located at DESY: 5 GeV e- beam Sharing: - magnet : KEK, Japan - field cage : DESY, Germany - Cosmic trigger : Saclay, France - endplate : Cornell, USA Testing: - Micromegas : Saclay, France, Carleton/Montreal, Canada - GEM : Saga, Japan, Tsinghua, China - TimePix pixel : F, D, NL ILC-TPC Large Prototype W. Wang - FCPPL workshopLyon, 09/04/2010 7 ILD TPC

9. pads mesh E B resistive foil glue pads mesh E B Micromegas with Resistive Anode Micromegas with Resistive Anode Pad width limits MPGD TPC resolution Direct signal readout technique A centroid calculation less precise : pad width  0 : resolution at Z=0 without diffusion Lyon, 09/04/2010W. Wang - FCPPL workshop 8 Charge dispersion technique with a resistive anode so that wide pads can be used for centroid determination

10. Resistive ink ~3 MΩ/□ Resistive Kapton ~5 MΩ/□ Standard 2 Resistive Kapton ~3 MΩ/□ Micromegas Modules for TPC Lyon, 09/04/2010W. Wang - FCPPL workshop 9

11. Lyon, 09/04/2010W. Wang - FCPPL workshop AFTER-based electronics (72 channels/chip) from T2K experiment: – low-noise (700 e-) pre-amplifier-shaper – 100 ns to 2 μs tunable peaking time – Zero Suppression capability – full wave sampling by SCA Bulk Micromegas detector: 1726 (24x72) pads of ~3x7 mm² T2K Electronics Characteristics –frequency tunable from 1 to 100 MHz (most data at 25 MHz) –12 bit ADC (rms pedestals 4 to 6 channels) –pulser for calibration 10

12. NEW ELECTRONICS – FLAT ON THE BACK OF THE MODULE 11 T2K Electronics Lyon, 09/04/2010W. Wang - FCPPL workshop Goal : Fully equip 7 modules with more integrated electronics, still based on the T2K AFTER chip. First prototype in June 2010 Tests at fall 2010 Then production and characterization of 9 modules in 2011 at the CERN T2K clean room

13. Data Analysis Results 12 Lyon, 09/04/2010W. Wang - FCPPL workshop

14. B=0 data : Drift velocity measurements 13 V drift = 7.698 +- 0.040 cm/µs at E=230 V/cm (Magboltz : 7.583+-0.025(gas comp.)) The difference is 1.5+-0.6 % Data Analysis Results Lyon, 09/04/2010W. Wang - FCPPL workshop Drift Velocity in T2K gas compared to Magboltz simulations for - P=1035 hPa - T=19°C - 35 ppm H 2 0 ( T2K gas: Ar:CF4:iso=95:3:2)

15. 14 Lyon, 09/04/2010W. Wang - FCPPL workshop Data Analysis Results PRF : Pad Response Function a measure of signal size as a function of track position relative to the pad using pulse shape information to optimize the PRF The PRF: → is not Gaussian. → can be characterized by its FWHM  (z) & base Width  (z).  

16. PRF(Pad Response Functions) fits, z ~ 5 cm 15 B=1T data : comparison of resistive ink and Carbon-loaded Kapton Lyon, 09/04/2010 W. Wang - FCPPL workshop Data Analysis Results

17. Position residuals x row -x track 16 Lyon, 09/04/2010 W. Wang - FCPPL workshop

18. Z=5cm Z=35cm Z=50cm MEAN RESIDUAL vs ROW number Z-independent distortions Distortions up to 50 microns for resistive paint Rms 7 microns for CLK film 17 Lyon, 09/04/2010W. Wang - FCPPL workshop Data Analysis Results

19. Lyon, 09/04/2010W. Wang - FCPPL workshop Data Analysis Results  0 : the resolution at Z=0 N eff : the effective number of electrons Resistive CLK:  0 =52.7 μm 18

20. Dependence of resolution with data taking conditions 19 Resolution at z=5cm (µm) V mesh (V) Lyon, 09/04/2010W. Wang - FCPPL workshop Data Analysis Results

21. I. ILC-TPC 1.2 Tsinghua GEM-TPC (TU-TPC) 1.2 Tsinghua GEM-TPC (TU-TPC) Lyon, 09/04/2010W. Wang - FCPPL workshop 20

22. Tsinghua GEM-TPC (TU-TPC) Small TU-TPC prototype (GEM-TPC) Lyon, 09/04/2010W. Wang - FCPPL workshop 21 Total: 99 strips Pitch: 5 mm Strip Width: 2 mm Maximum drift length: 50cm Readout detector: triple-GEM Scheme of TU-TPC prototype

23. Tsinghua GEM-TPC Improvement Improvement @ TU-TPC – Field cage: single-side strip to mirror strip: done – Guard ring: adopted – DAQ: from Q, T separately, to pulse sampling, delayed, but coming soon – Space charge calculation Lyon, 09/04/2010W. Wang - FCPPL workshop 22

24. II. Fast Neutron Imaging Micromegas Detector Imaging Micromegas Detector Lyon, 09/04/2010W. Wang - FCPPL workshop 23

25. Lyon, 09/04/2010W. Wang - FCPPL workshop Fast Neutron Imaging Micromegas Detector Fast Neutron Imaging Micromegas Detector 24 Scheme of the gadolinium foil (100 μm) etching and image obtained with the Micromegas detector. The typical conversion reactions: H(n,n)p 10 B(n,α) 7 Li 6 Li(n,α)t α n → t p F. Jeanneau et al. IEEE Transactions on Nuclear Science, vol. 53, issue 2, pp. 595-600

26. Lyon, 09/04/2010W. Wang - FCPPL workshop Fast Neutron Imaging Micromegas Detector Fast Neutron Imaging Micromegas Detector Readout electronics using AFTER-based electronics (made by Saclay) 25

27. Fast Neutron Imaging Micromegas Detector Fast Neutron Imaging Micromegas Detector Lyon, 09/04/2010W. Wang - FCPPL workshop 26 PCB design for fast neutron detector ( six T2K front end cards ~2000 pixels 1.5mm )

28. Present - August 2010: Design, construction, transportation and assembly of fast neutron detector; September 2010: Date taking with fast neutron detector using a 14MeV neutron beam in Lanzhou University. Lyon, 09/04/2010W. Wang - FCPPL workshop Fast Neutron Imaging Micromegas Detector Fast Neutron Imaging Micromegas Detector 27

29. Micromegas ILC-TPC: Since December 2008, 5 modules of Micromegas TPC have been measured and got good results. The concept is globally validated. Next step well advanced : 7 modules to fully equip the present endplate. Fast Neutron Imaging Micromegas Detector: We have finished the basic design of fast neutron Micromegas detector and will take data in this year. All these make good preparation for research of neutron imaging. Conclusions Conclusions Lyon, 09/04/2010W. Wang - FCPPL workshop 28

30. Lyon, 09/04/2010W. Wang - FCPPL workshop 29