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Beam tests of a Micromegas Large TPC Prototype. D. Attié. SINP, January 22 th , 2010. Overview. Introduction, technological choice for ILC-TPC The Large TPC Prototype for ILC Bulk Micromegas with resistive anodes Beam test conditions, T2K electronics Data analysis results:
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Beam tests of a Micromegas Large TPC Prototype D. Attié SINP, January 22th, 2010 WP meeting 94
Overview Introduction, technological choice for ILC-TPC • The Large TPC Prototype for ILC • Bulk Micromegas with resistive anodes • Beam test conditions, T2K electronics • Data analysis results: • Drift velocity • Pad response function • Resolution • Comparison between two resistive modules • Future plans: • Pixelized Micromegas module • Integrated electronics for 7 modules Conclusion SINP seminar ̶ January 22th, 2010
How to improve the spatial resolution? • Need for ILC: measure 200 track points with a transverse resolution ~ 100 μm • - example of track separation with 1 mm x 6 mm pad size: • 1,2 × 106 channels of electronics • sz=0 > 250 μm amplification avalanche over one pad • Spatial resolution σxy: • - limited by the pad size (s0 ~ width/√12) • - charge distribution narrow (RMSavalanche ~ 15 μm) Calculation for the ILC-TPC • 1. Decrease the pad size: narrowed strips, pixels • + single electron efficiency • need to identify the electron clusters 55 mm D.C. Arogancia et al., NIMA 602 (2009) 403 1. Pixels • 2. Spread charge over several pads: resistive anode • + reduce number of channels, cost and budget • + protect the electronics • limit the track separation • need offline computing 2. Resistive anode SINP seminar ̶ January 22th, 2010
Large TPC Prototype for ILC • Built by the collaboration LC-TPC • Financed by EUDET • Located at DESY: 6 GeV e- beam • Sharing out : • - magnet: KEK, Japan • - field cage: DESY, Germany • - trigger: Saclay, France • - endplate: Cornell, USA • - Si envelope: OAW, Austria • - laser: Victoria U., Canada • - Micromegas: Saclay, France, Carleton/Montreal U., Canada • - GEM: Saga, Japan • - TimePix pixel: F, G, NL SINP seminar ̶ January 22th, 2010
Large TPC Prototype for ILC SINP seminar ̶ January 22th, 2010
Large TPC Prototype for ILC • 60 cm long TPC • Endplate ø = 80 cm of 7 interchangeable panels of 23 cm • to fit in 1T superconductingmagnet 24 rows x 72 columns <pad size> ~ 3x7 mm2 80 cm SINP seminar ̶ January 22th, 2010
Module presently avalaible 2 Resistive Kapton ~1 MΩ/□ Resistive Kapton ~4 MΩ/□ Standard Resistive ink ~1 MΩ/□ SINP seminar ̶ January 22th, 2010
Beam test conditions at B=1T • Bulk Micromegas detector: 1726 (24x72) pads of ~3x7 mm² • AFTER-based electronics (72 channels/chip): • low-noise (700 e-) pre-amplifier-shaper • 100 ns to 2 μs tunable peaking time • full wave sampling by SCA • Beam data (5 GeV electrons) were taken at several z values by sliding the TPC in the magnet. Beam size was 4 mm rms. • frequency tunable from 1 to 100 MHz (most data at 25 MHz) • 12 bit ADC (rms pedestals 4 to 6 channels) 6 FECs and 1 FEM in its shielding SINP seminar ̶ January 22th, 2010
Determination of z range • Cosmic run at 25 MHz of sampling frequency time bin = 40 ns • Drift velocity in T2K gas (Ar/CF4/iso-C4H10, 95/3/2) at 230 V/cm: • TPC length = 56.7 cm agreement with survey 220 time bins SINP seminar ̶ January 22th, 2010
Pad signals: beam data sample • RUN 284 • B = 1T • T2K gas • Peaking time: 100 ns • Frequency: 25 MHz SINP seminar ̶ January 22th, 2010
Two-track separation φ r z SINP seminar ̶ January 22th, 2010
Drift velocitymeasurement • Measured drift velocity (Edrift = 230 V/cm, 1002 mbar): 7.56 ± 0.02 cm/s • Magboltz: 7.548 ± 0.003 cm/sin Ar/CF4/iso-C4H10/H2O (95:3:2:100ppm) B = 0T SINP seminar ̶ January 22th, 2010
Determination of the Pad Response Function Pad pitch • Fraction of the row charge • on a pad vsxpad – xtrack • (normalized to central pad charge) • Clearly shows charge spreading • over 2-3 pads • (data with 500 ns shaping) • Then fit x(cluster) using this • shape with a χ² fit, • and fit simultaneously all lines xpad – xtrack (mm) See Madhu Dixit’s talk xpad – xtrack (mm) SINP seminar ̶ January 22th, 2010
Spatial resolution • Resolution at z=0: σ0 = 54.8±1.6 mwith 2.7-3.2 mm pads (wpad/55) • Effective number of electrons: Neff = 31.81.4 consistent with expectations SINP seminar ̶ January 22th, 2010
Field distortion measurement using laser • Two laser devices installed on the endplate to light up photosensitive pattern • on the cathode (spots and line) • Deterioration of resolution at z > 40 cm : due to low field 0.9 to 0.7 T • in the last 20 cm (significant increase of transverse diffusion) Photoelectrons from the cathode pattern B field map of the magnet 50 cm 30 cm 5 cm Beam position SINP seminar ̶ January 22th, 2010
Description of the resistive anodes Resistive Kapton ResistiveInk Resistive Ink Resistive Kapton Prepreg Prepreg PCB PCB SINP seminar ̶ January 22th, 2010
Comparison at B=1T, z ~ 5 cm ResistiveKapton ResistiveInk • RUN 310 • Vdrift= 230 cm/s • Vmesh = 380 V • Peaking time: 500 ns • Frequency Sampling: 25 MHz • RUN 549 • Vdrift = 230 cm/s • Vmesh = 360 V • Peaking time: 500 ns • Frequency Sampling: 25 MHz SINP seminar ̶ January 22th, 2010
Pad ResponseFunctions, z ~ 5 cm ResistiveInk ResistiveKapton xpad – xtrack(mm) xpad – xtrack(mm) Γ² = 7 mm Γ² = 11 mm δ = 10 mm δ= 13 mm xpad – xtrack(mm) xpad – xtrack(mm) σz=5 cm = 68 µm σz=5cm = 130 µm ! SINP seminar ̶ January 22th, 2010
2.2 GeVMomentum • B=1T • Beam energy set to 2.2 GeV using one module in the center • Simple Landau fit MPV = 2.2 GeV SINP seminar ̶ January 22th, 2010
Tests with Si envelope (nov. 2009) From Vienna Si Si SINP seminar ̶ January 22th, 2010
Synchronized events with Si envelope Resistive Ink TLU Resistive Kapton SINP seminar ̶ January 22th, 2010
Description of the TimePix chip 55 mm m μ 14080 m (pixel array) 55 4 4 16120 m 55 mm 2 2 3 3 1 1 5 5 55 μ m 14111 m • Chip (CMOS ASIC) upgraded in the EUDET framework from the Medipix chip developed first for medical applications • IBM technology 0.25 m • Characteristics: • surface: 1.4 x 1.6 cm2 • matrix of 256 x 256 • pixel size: 55 x 55 μm2 • For each pixel: • preamp/shaper • threshold discriminator • register for configuration • TimePix synchronization logic • 14-bit counter • Noise: ~ 650 e- • Cin ~ 15 fF Pixel Synchronization Logic Interface Configuration latches Preamp/shaper Counter THL disc. SINP seminar ̶ January 22th, 2010
TimePix synchronization logic control Medipix Mode Timepix Mode TOT Mode not detected detected Charge summed • Each pixel can be configured independently in 5 different modes • Internal clock up to 100 MHz 100 MHz Internal shutter Shutter Internal clock 10 ns Digital signal Analog signal SINP seminar ̶ January 22th, 2010
Micro-TPCTimePix/Micromegas Windows for X-ray sources • Micro-TPC with a 6 cm height field cage • Size : 4 cm × 5 cm × 8 cm • Read out by MUROS or USB1.2 devices • Two detectors are available now at Saclay Cover Windows for β sources Field cage 6 cm Micromegas mesh TimePix chip SINP seminar ̶ January 22th, 2010
Micro-TPCTimePix/Micromegas: Time mode • TimePix chip • + SiProt 20 μm • + Micromegas • 55Fe source • Ar/Iso (95:5) • Time mode • z = 25 mm • Vmesh = -340 V • tshutter = 283 μs SINP seminar ̶ January 22th, 2010
Micro-TPCTimePix/Micromegas: Time mode • TimePix chip • + SiProt 20 μm • + Micromegas • 90Sr source • Ar/Iso (95:5) • Time mode • z ~ 40 mm • Vmesh = -340 V • tshutter = 180 μs SINP seminar ̶ January 22th, 2010
2×4 TimePix/InGrid matrix module • Mother card • Mezzanine card • Guard ring card • Heat dissipation block SINP seminar ̶ January 22th, 2010
Further tests for resistive bulk Micromegas Resistive technology choice In 2008/2009 with one detector module In 2010/2011 with 7 detector modules Reduce the electronics to fit to the module and power consumption SINP seminar ̶ January 22th, 2010
7-modules project FEC FEM PCB detector (bottom) SINP seminar ̶ January 22th, 2010
7-modules project SINP seminar ̶ January 22th, 2010
7-modules project • Remove packaging and protection diodes • Use 2 × 300 pins connector • Replace resistors SMC 0603 by 0402 (1 mm × 0.5 mm) 25 cm FEC 12,5 cm 4,5 cm 14 cm 2,8 cm 3,5 cm 0,78 cm 3,5 cm Chip 0,74 cm SINP seminar ̶ January 22th, 2010
Conclusions • Three Micromegas technologies with resistive anode have been tested within the EUDET facility using 1T magnet to reduce the transverse diffusion • C-loaded Katpon (4 MΩ/□) technology gives better results than resistive ink technology • Data analysis results confirm excellent resolution at small distance with the resistive C-loaded Kapton (4 MΩ/□): 55 m for 3 mm pads • Data analysis of laser tests and the second resistive C-loaded Kapton (1 MΩ/□) should be done soon. • Plans are to test several resistive layer manufacturing process and capacitance/resistivity, then go to 7 modules with integrated electronics by the end of this year SINP seminar ̶ January 22th, 2010
Dhanyavad SINP seminar ̶ January 22th, 2010
Backup slides SINP seminar ̶ January 22th, 2010
TimePix chip architecture • Clock per pixel up to 100 MHz • Characteristics: • analog power: 440 mW • digital power (Ref_Clk = 80 MHz): 450 mW • serial readout (@ 100 MHz): 9.17 ms • parallel readout (@ 100 MHz): 287 μs • > 36 M transistors on 6 layers • Pixel modes: • masked • counting mode (Medipix, Timepix-1h) • Time-Over-Threshold “charge” info • Common stop “time” info SINP seminar ̶ January 22th, 2010
TimePix chip schematic Previous Pixel For each pixel Ref_Clkb Clk_Read Mux 4 bits thr Adj Mask Mux Preamp Input Disc 14 bits Shift Register Shutter THR Timepix Synchronization Logic Shutter_int Ctest P0 Conf Testbit Polarity P1 8 bits configuration Test Input Ovf Control Ref_Clk Clk_Read Next Pixel Digital part Analogic part SINP seminar ̶ January 22th, 2010
Readout system for Medipix/TimePix chip • MUROSv2.1: • Serial readout • VHDCI cable of length <3m • read 8 chips in mosaic • tunable clock [30-200MHz] • ~40fps @160MHz • http://www.nikhef.nl/pub/experiments/medipix/muros.html • USB: • Serial readout • ~5 fps@20MHz • http://www.utef.cvut.cz/medipix/usb/usb.html • Mosaic achitecture: SINP seminar ̶ January 22th, 2010
Detectors using Medipix2/TimePix chip + - Single pixel readout cell + + - - Solid detector Gas detector x, y, F(x, y) x, y, z(t), E(x,y) Drift grid X-ray source Ionizing particle Gas volume Semiconductor sensor Flip-chip bump bonding connections Amplification System (MPGD) Medipix2/TimePix chip Medipix2 chip SINP seminar ̶ January 22th, 2010