Micromegas TPC Part II : experiments CCAST Micromegas TPC Part II : experiments P. Colas, Saclay Lectures at the TPC school, Tsinghua University, Beijing, January 7-11, 2008 January 10, 2008 Micromegas TPC

OUTLINE PART I – operation and properties TPC, drift and amplification Micromegas principle of operation Micromegas properties Gain stability and uniformity, optimal gap Energy resolution Electron collection efficiency and transparency Ion feedback suppression Micromegas manufacturing meshes and pillars InGrid “bulk” technology Resistive anode Micromegas Digital TPC January 10, 2008 Micromegas TPC

OUTLINE PART II – Micromegas experiments The COMPASS experiment The CAST experiment The KABES beam spectrometer The T2K ND-280 TPC The Large Prototype for the ILC Micromegas neutron detectors TPCs for Dark Matter search and neutrino studies January 10, 2008 Micromegas TPC

COMPASS MIP detection for measuring the nucleon spin structure High particle flow : 105 kHz/cm2 Sparks give less than 1 per mil dead time Space resolution < 70 mm with 350 mm strips The largest Micromegas so far (40x40 cm2) In operation at CERN since 2002 efficiency>97% Going to hadrons and new non-magnetic cathodes in 2008 (with a new magnet) January 10, 2008 Micromegas TPC

CAST X ray CERN Axion Solar Telescope Solar Axion detection : con- version of solar axions in a LHC magnet -> observe low-energy X-rays 2D with overlayed crossed strips In operation at CERN since 2003 Improvements in progress (energy resolution, shielding, new detector, golden cathode to avoid copper fluorescence, new optics) axions Transverse magnetic field (B) X ray detector L January 10, 2008 Micromegas TPC

CAST Low threshold : 600 eV ! Low background (fluorescence) Ar 6.5 keV g X y Low threshold : 600 eV ! Low background (fluorescence) Cu escape Fe Ar Low energy spectrum from Micromegas in CAST January 10, 2008 Micromegas TPC

NA48/KABES Tdrift2 KAon BEam Spectrometer Micromegas Gap 50 μm Tdrift1 Micromegas TPC for CP violation expt in operation at CERN from summer 2003 to end of 2004. Extension for K+ -> pnn project (25 micron gap)? Time resolution: 0.6 ns Tagged K track Space resolution from drift time measurement: 70 μm (T0)KABES- (T0)DCH Spectrometer (ns) XStation 1 or 2 - XStation 3 (cm) Tagging with reconstructed K±  ± +  - January 10, 2008 Micromegas TPC

January 10, 2008 Micromegas TPC

Neutron detection Use a converter to extract alphas Numerous applications: neutron tomography, neutron detection in hostile environments January 10, 2008 Micromegas TPC

Numerous applications: neutron tomography, neutron detection in hostile environments January 10, 2008 Micromegas TPC

January 10, 2008 Micromegas TPC

X-ray Radiography (Roentgen 1895) : see bones through skin and meat Neutron Radiography : see gas (H2) through glass and metal Very useful for rocket engine studies January 10, 2008 Micromegas TPC

T2K : Tokai to Kamiokande Long Base Line neutrino experiment with an intense beam (0.75MW) Aiming at q13 , and “atmospheric oscillation” measurements. 2 detectors: far (SK) and near at 280 m from target Off-axis beam JPARC currently under construction  first beam 2009 January 10, 2008 Micromegas TPC

T2K Physics Goals P(νμ→ νμ)≈1- cos4 θ13 sin2 2θ23 sin2 (1.27 Δm223 L/Eν)  disappearance Need flux and spectrum measurement at ND280 detector 5000 ev/year SK, 105 ev/year ND280 P(νμ→ νe)≈sin2 2θ13 sin2 (1.27 Δm213 L/Eν) 1-sin2(2θ23) Δ(m23)2 Eν(MeV) 100 ev/5 years for sin2(2θ13)=0.1, BKG 15 Need νe contamination at ND280 and study of other backgrounds January 10, 2008 Micromegas TPC

Purpose of ND280 Measure the neutrino spectrum before oscillation. Measure the intrinsic e beam contamination from  and kaon decays. Measure the 0 production in Neutral Current with neutrino flux close to the one at SK. Measure the exclusive cross-sections at the relevant energies (< 1Gev). Measure nuclear effects that are relevant at these energies: Proton and pion rescattering and charge exchange. B = 0.2 T January 10, 2008 Micromegas TPC

T2K 3 TPC stations 2.5 m y z x 2.5 m Detector module 1 m Started in December 2004, should take data end 2009 3 TPCs stations; each with 2 planes of detector modules → From the beginning, think wide operating ranges, flexible hardware modular architecture, design staging January 10, 2008 Micromegas TPC

Switched capacitor array The T2K TPC TCP/IP PC Linux 6 DCCs VME/PCI backplane bus Gigabit Ethernet DAQ control Detector B A Global trigger Réseau 3 TPC 1 m 2,5 m 1 of 6 TPC planes (12-modules) Outside magnet Inside magnet 1 of 6 Data Concentrator Card 12 duplex Optical fibres x 6 Front End Mezzanine Card (FEM) 288 channel Front End Card (FEC) 1728 pad Micromegas plane Slow control network Optical fiber to/from DCC Power bar Low voltage Power supply 1 of 72 modules 1 of 1728 Front-End ASIC “AFTER” 72 channel x 511 time buckets Switched capacitor array January 10, 2008 Micromegas TPC

AFTER SCA: 76x511 Cells Technology: AMS CMOS 0.35mm Number of transistors: 400,000 Area: 7546mm x 7139 mm Package: LQFP 160 pins; 30 x 30 x 1.4 mm pitch: 0.65 mm Submission: 24 April 2006 Delivery: end of July 2006 Characterization: October 2006 – March 2007 SCA: 76x511 Cells January 10, 2008 Micromegas TPC

Connectors to detector plane ASIC 4 channel ADC Passive Components Connectors to detector plane 288 channel FE card Digital output ~25 cm ~12 cm → Foresee FEC PRR in ~Q1-2008 and production in ~Q2-Q3 2008 January 10, 2008 Micromegas TPC

Front-End Mezzanine → Foresee FEM Production Readiness Review in ~Q3-2008 and production in ~Q4 2008 January 10, 2008 Micromegas TPC

Detector Module Read-out Electronics 288-channel analog Front-End Card (FEC) 1728-pad detector plane 80-pin connector 72-channel ASIC Slow-control Network - CANbus Quad-channel ADC digital Front-end Mezzanine card (FEM) FPGA Fiber to DCC Optical Transceiver Low voltage power 84 modules in total Data taking at CERN on Harp setup in Sept. 07 electronics was very stable during the 10-day period of data taking January 10, 2008 Micromegas TPC

Production and Test Bench at CERN University of Geneva, Barcelona January 10, 2008 Micromegas TPC

Read-out board Coverlay lamination Detector developed cured tested January 10, 2008 Micromegas TPC

January 10, 2008 Micromegas TPC

January 10, 2008 Micromegas TPC

Bulk detectors are now very stable. Gains up to 60000 But run at 700-800 Ar CF4 Isobutane 95:3:2 January 10, 2008 Micromegas TPC

36x34 cm2 1728 pads Pad pitch 6.9x9 mm2 January 10, 2008 Micromegas TPC

1 ‘spark’ (100 nA) per 10 hours without beam. Gain about 800 ! 1 ‘spark’ (100 nA) per 10 hours without beam. January 10, 2008 Micromegas TPC

Cluster space point resolution in T2K B=0.2T Cluster space point resolution in T2K 2005 1-pad clusters < 700 m @ 1m 2-pad clusters Improved space point  for 2-pad clusters Larger fraction of > 1-pad clusters (low-noise FEE) Preliminary values of dE/dx resolution for ~ 35cm long tracks (E=160V/cm): - 12.4% B=0.2T - 11.1% B=0.4T  should fulfill requested resolutions of 10% for ~70cm long tracks on both P @ 1 GeV/c and dE/dx B=0.2T 2007 < 600 m @ 1m 2-pad clusters 1-pad clusters January 10, 2008 Micromegas TPC

Micromegas Panels for Large Prototype Resistive anode from the start -> resistive “bulk” Use of T2K electronics Several solutions for the resistive layer and the mesh under study January 10, 2008 Micromegas TPC

AFTER-chip based readout The most compact at present: 72 channels Very flexible : 10 to 100 MHz sampling, shaping: peaking time from 90 to 800 ns, can be switched off, zero suppression. Production decided last October 12. Will take place in Q3 2008 (140 000 channels for T2K, 14000 for LC-TPC LP) January 10, 2008 Micromegas TPC

MICROMEGAS + RESIST. FOIL PANEL 24 rows x 72 pads HV Resistive layer grounding Av. Pad pitch 3.2 x 7 mm January 10, 2008 Micromegas TPC

connector side Detector side January 10, 2008 Micromegas TPC

TimePix multi-chip panel Daisy-chained chips to be equipped with InGrids TimePix multi-chip panel 2x4 matrix SiProt+Ingrid 1 MUROS Pad ~ 2,8 x 6, 8 mm² January 10, 2008 Micromegas TPC

ATLAS muon chambers for SLHC average single count rates for L=1034 cm-2s-1 January 10, 2008 Micromegas TPC

ATLAS Micromegas R&D Collaboration Evaluate possible use of micromegas for ATLAS muon chamber upgrade programme EoI submitted in February 2007 to ATLAS Upgrade Office Proposal submitted in June 2007 Expect approval by ATLAS EB in the near future . . . 15 participating Institutes so far; with growing interest ... Regular weekly meetings at CERN since February TWiki page https://twiki.cern.ch/twiki/bin/view/Atlas/MuonMicromegas January 10, 2008 Micromegas TPC

Goals Phase I: Build and evaluate small prototype(s) based on micromegas technology to get familiar with technology demonstrate required performance Decide on Operating parameters (gas, gas gain, HV, etc...) Readout pattern & electronics Phase II: Develop techniques for the construction of large-size detectors (1m x 2m) January 10, 2008 Micromegas TPC

The mesh(es) Mesh–readout electrode distance: 128 µm Prototype 1 (P1) Homogeneous stainless steel mesh 325 lines/inch = 78 µm pitch wire diameter: 20–25 µm Prototype 2 (P2) Unidirectional stainless steel/plastic mesh 200 lines/inch = 127 µm pitch wire diameter: 40–45 µm January 10, 2008 Micromegas TPC

Prototype assembling Al frame on both sides Cathode mounting Assembled chamber 4/24/17 39 January 10, 2008 Micromegas TPC

Dark matter search More neutrino physics Look for recoiling nuclei (few 100 keV) Directionality : see the ‘wind of wimps’ : 24h-modulation of the direction Many projects, many of them use Micromegas Negative ion TPC : take an attaching gas (CS2, CH3NO3), drift negative ions, they are stripped in the amplification region. Very slow drift, but very low diffusion More neutrino physics Neutrinoless double-beta decay in 136Xe January 10, 2008 Micromegas TPC

CONCLUSION Micromegas is a very versatile detector suited to detection of charged particles, neutrons, photons, with high rate, high resolution (E,t,x), low rad. length, large surfaces, low cost, easy operation, robustness, good aging properties, etc… Matter for this talk principally comes from: IEEE/MPGD workshops, San Diego, October 29, 2006 and Honolulu, October 28, 2007, CERN, September 11, 2008 3rd Symposium on Large TPCs for Low Energy Rare Events, Paris, December 11-12, 2006 Recent work in Aachen, DESY, KEK, CERN, Carleton, Saclay… January 10, 2008 Micromegas TPC

THANKS To all colleagues from whom I stole transparencies or plots: I. Giomataris, B. Peyaud, T. Lux, E. Mazzucato, M. Zito, D. Calvet, J. Wotschak, R. de Oliveira, S. Andriamonje, M. Dixit, M. Riallot, A. Delbart, D. Attié, M. Chefdeville, S. Biagi, J. Martoff For the animations : Gilles Barouch, Dan Burke, D. Attié Questions/remarks: paul.colas@cea.fr January 10, 2008 Micromegas TPC

Information RD51 workshop April 16-18 in Amsterdam http://www.nikhef.nl/pub/conferences/rd51/ IEEE/NSS in Dresden October 19-25 http://www.nss-mic.org/2008/NSSMain.asp Large TPCs for Low Energy Rare Events (Paris, December 18-19) January 10, 2008 Micromegas TPC