Large TPCs for HEP ILC-TPC & Fast Neutron detector Wenxin Wang (D. Attié, P. Colas, E. Delagnes, Yuanning Gao, Bitao Hu, Bo Li, Yulan Li, M. Riallot, Xiaodong Zhang)

Self-Introduction 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” 1.2×0.4m2 Micromegas prototype Micromegas Digital HCAL Lyon, 09/04/2010 W. Wang - FCPPL workshop

Outline ILC-TPC 1.2 Tsinghua GEM-TPC improvement (TU-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) Fast Neutron Imaging Micromegas Detector Lyon, 09/04/2010 W. Wang - FCPPL workshop

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

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

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

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

ILC-TPC Large Prototype 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 TPC ILD Lyon, 09/04/2010 W. Wang - FCPPL workshop

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

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

T2K Electronics Characteristics 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 frequency tunable from 1 to 100 MHz (most data at 25 MHz) 12 bit ADC (rms pedestals 4 to 6 channels) pulser for calibration Lyon, 09/04/2010 W. Wang - FCPPL workshop

T2K Electronics NEW ELECTRONICS – FLAT ON THE BACK OF THE MODULE 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 Lyon, 09/04/2010 W. Wang - FCPPL workshop

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

B=0 data : Drift velocity measurements Data Analysis Results Drift Velocity in T2K gas compared to Magboltz simulations for - P=1035 hPa - T=19°C - 35 ppm H20 ( T2K gas: Ar:CF4:iso=95:3:2) Vdrift = 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 % B=0 data : Drift velocity measurements Lyon, 09/04/2010 W. 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). Lyon, 09/04/2010 W. Wang - FCPPL workshop

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

Data Analysis Results Position residuals xrow-xtrack Lyon, 09/04/2010 W. Wang - FCPPL workshop

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

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

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

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

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

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, 09/04/2010 W. Wang - FCPPL workshop

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

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

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

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

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

Fast Neutron Imaging Micromegas Detector: Conclusions 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. Lyon, 09/04/2010 W. Wang - FCPPL workshop

Thank you for your attention And Thanks to all others for the texts and pictures I “borrowed” Lyon, 09/04/2010 W. Wang - FCPPL workshop