Nov. 11, 2009 WP meeting 94 1 D. Attié SINP, January 22 th, 2010 Beam tests of a Micromegas Large TPC Prototype

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 22 th, 2010

 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 How to improve the spatial resolution? 3 SINP seminar ̶ January 22 th, 2010 Need for ILC: measure 200 track points with a transverse resolution ~ 100 μ m - example of track separation with 1 mm x 6 mm pad size:  1,2 × 10 6 channels of electronics  s z=0 > 250 μ m amplification avalanche over one pad Spatial resolution σ xy : - limited by the pad size (s 0 ~ width/√12) - charge distribution narrow (RMS avalanche ~ 15 μ m)  1. Decrease the pad size: narrowed strips, pixels + single electron efficiency –need to identify the electron clusters 2. Resistive anode Calculation for the ILC-TPC D.C. Arogancia et al., NIMA 602 (2009) mm 1. Pixels

Large TPC Prototype for ILC SINP seminar ̶ January 22 th, 2010 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

Large TPC Prototype for ILC SINP seminar ̶ January 22 th, 2010

Large TPC Prototype for ILC SINP seminar ̶ January 22 th, cm long TPC Endplate ø = 80 cm of 7 interchangeable panels of 23 cm  to fit in 1T superconducting magnet 24 rows x 72 columns ~ 3x7 mm 2 80 cm

Module presently avalaible SINP seminar ̶ January 22 th, 2010 Resistive ink ~1 MΩ/□ Resistive Kapton ~4 MΩ/□ Standard 2 Resistive Kapton ~1 MΩ/□

Beam test conditions at B=1T SINP seminar ̶ January 22 th, 2010 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 μ s 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

Determination of z range SINP seminar ̶ January 22 th, 2010 Cosmic run at 25 MHz of sampling frequency  time bin = 40 ns Drift velocity in T2K gas (Ar/CF 4 /iso-C 4 H 10, 95/3/2) at 230 V/cm: TPC length = 56.7 cm agreement with survey 220 time bins

Pad signals: beam data sample SINP seminar ̶ January 22 th, 2010 RUN 284 B = 1T T2K gas Peaking time: 100 ns Frequency: 25 MHz

Two-track separation SINP seminar ̶ January 22 th, 2010 r φ z

Drift velocity measurement SINP seminar ̶ January 22 th, 2010 Measured drift velocity (E drift = 230 V/cm, 1002 mbar): 7.56 ± 0.02 cm/  s Magboltz: ± cm/  s in Ar/CF 4 /iso-C 4 H 10 /H 2 O (95:3:2:100ppm) B = 0T

Determination of the Pad Response Function SINP seminar ̶ January 22 th, 2010 Fraction of the row charge on a pad vs x pad – x track (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 χ ² fit, and fit simultaneously all lines x pad – x track (mm)  Pad pitch  See Madhu Dixit’s talk x pad – x track (mm)

Spatial resolution SINP seminar ̶ January 22 th, 2010 Resolution at z=0: σ 0 = 54.8±1.6  m with mm pads (w pad /55) Effective number of electrons: N eff = 31.8  1.4 consistent with expectations

Field distortion measurement using laser SINP seminar ̶ January 22 th, 2010 Beam position 5 cm 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) 30 cm50 cm B field map of the magnet Photoelectrons from the cathode pattern

Description of the resistive anodes SINP seminar ̶ January 22 th, 2010 DetectorDielectric layerResistive layer Resistivity (M Ω / □ ) Resistive Kapton Epoxy-glass 75 μ m C-loaded Kapton 25 μ m ~4-8 Resistive Ink Epoxy-glass 75 μ m Ink (3 layers) ~50 μ m ~1-2 Resistive KaptonResistive Ink PCB Prepreg Resistive Kapton PCB Prepreg Resistive Ink

Comparison at B=1T, z ~ 5 cm SINP seminar ̶ January 22 th, 2010 Resistive KaptonResistive Ink RUN 310 V drift = 230 cm/  s V mesh = 380 V Peaking time: 500 ns Frequency Sampling: 25 MHz RUN 549 V drift = 230 cm/  s V mesh = 360 V Peaking time: 500 ns Frequency Sampling: 25 MHz

Pad Response Functions, z ~ 5 cm SINP seminar ̶ January 22 th, 2010 Resistive KaptonResistive Ink Γ ² = 7 mm δ = 10 mm Γ ² = 11 mm δ = 13 mm x pad – x track (mm)  σ z=5 cm = 68 µm  σ z=5cm = 130 µm ! x pad – x track (mm)

2.2 GeV Momentum SINP seminar ̶ January 22 th, 2010 B=1T Beam energy set to 2.2 GeV using one module in the center Simple Landau fit  MPV = 2.2 GeV

Tests with Si envelope (nov. 2009) SINP seminar ̶ January 22 th, 2010 Si From Vienna

Synchronized events with Si envelope SINP seminar ̶ January 22 th, 2010 TLU Resistive Ink Resistive Kapton

Description of the TimePix chip SINP seminar ̶ January 22 th, 2010 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 cm 2 –matrix of 256 x 256 –pixel size: 55 x 55 μ m 2 For each pixel: –preamp/shaper –threshold discriminator –register for configuration –TimePix synchronization logic –14-bit counter Noise: ~ 650 e- –C in ~ 15 fF 55  m Pixel  m  m  m (pixel array) μ m μ m Preamp/shaper THL disc. Configuration latches Interface Counter Synchronization Logic

TimePix synchronization logic control SINP seminar ̶ January 22 th, 2010 Medipix ModeTOT ModeTimepix Mode MaskP1P0Mode 000Masked Medipix 101TOT 110Timepix-1hit 111Timepix Each pixel can be configured independently in 5 different modes Internal clock up to 100 MHz Charge summed not detected detected 100 MHz Analog signal Internal shutter Shutter Internal clock Digital signal 10 ns

Micro-TPC TimePix/Micromegas SINP seminar ̶ January 22 th, 2010 Field cage Cover Micromegas mesh TimePix chip Windows for X-ray sources Windows for β sources 6 cm 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

Micro-TPC TimePix/Micromegas: Time mode SINP seminar ̶ January 22 th, 2010 TimePix chip + SiProt 20 μ m + Micromegas 55 Fe source Ar/Iso (95:5) Time mode z = 25 mm V mesh = -340 V t shutter = 283 μ s

Micro-TPC TimePix/Micromegas: Time mode SINP seminar ̶ January 22 th, 2010 TimePix chip + SiProt 20 μ m + Micromegas 90 Sr source Ar/Iso (95:5) Time mode z ~ 40 mm V mesh = -340 V t shutter = 180 μ s

2×4 TimePix/InGrid matrix module SINP seminar ̶ January 22 th, 2010 Mother card Mezzanine card Guard ring card Heat dissipation block

Further tests for resistive bulk Micromegas SINP seminar ̶ January 22 th, 2010 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 Resistive technology choice

7-modules project SINP seminar ̶ January 22 th, 2010 PCB detector (bottom) FEM FEC

7-modules project SINP seminar ̶ January 22 th, 2010

Remove packaging and protection diodes Use 2 × 300 pins connector Replace resistors SMC 0603 by 0402 (1 mm × 0.5 mm) 7-modules project SINP seminar ̶ January 22 th, cm 14 cm 0,78 cm 0,74 cm 4,5 cm 12,5 cm 2,8 cm 3,5 cm FEC Chip

Conclusions SINP seminar ̶ January 22 th, 2010 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 M Ω/□ ) technology gives better results than resistive ink technology Data analysis results confirm excellent resolution at small distance with the resistive C-loaded Kapton (4 M Ω/□ ): 55  m for 3 mm pads Data analysis of laser tests and the second resistive C-loaded Kapton (1 M Ω/□ ) 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 22 th, 2010 Dhanyavad

Backup slides SINP seminar ̶ January 22 th, 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 22 th, 2010

TimePix chip schematic Preamp Disc THR 14 bits Shift Register Input Ctest Testbit Test Input Mask 4 bits thr Adj Mux Clk_Read Previous Pixel Next Pixel Conf 8 bits configuration Polarity Analogic part Digital part Ref_Clk Timepix Synchronization Logic Ref_Clkb P0 P1 Shutter Ovf Control Clk_Read Shutter_in t For each pixel SINP seminar ̶ January 22 th, 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] USB: –Serial readout –~5 Mosaic achitecture: SINP seminar ̶ January 22 th, 2010

Detectors using Medipix2/TimePix chip Medipix2 chip Medipix2/TimePix chip X-ray source Ionizing particle Single pixel readout cell Flip-chip bump bonding connections Semiconductor sensor Gas volume Amplification System (MPGD) Drift grid Solid detector Gas detector x, y, F(x, y) x, y, z(t), E(x,y) SINP seminar ̶ January 22 th, 2010