Status report NIKHEF NIKHEFAuke-Pieter Colijn Alessandro Fornaini Harry van der Graaf Peter Kluit Jan Timmermans Jan Visschers Saclay CEA DAPNIAMaximilien Chefdeville Paul Colas Yannis Giomataris Arnaud Giganon Univ. Twente/Mesa+Jurriaan Schmitz CERN/Medipix ConstmEric Heijne Xavie Llopart Michael Campbell Thanks to: Wim Gotink Joop Rovenkamp TPC R&D phone/VRVS meeting 21/7/2004 PhD student per 1/9/04

Detection of single electrons using MediPix2/Micromegas assembly as Direct Pixel Segmented Anode Analysis of cosmic data 31/3-2/4 Final draft of NIM paper ready #pixels hit/mm track length = 1.83 #clusters/mm track length = 0.52 Single electron efficiency 0.9 Moire effects: mismatch in pixel and hole pitch: 60/(60-55) = 12 pixels repetition

He/Isobutane 80/20 Modified MediPix Sensitive area: 14 x 14 x 15 mm 3 Drift direction: Vertical max = 15 mm

He/Isobutane 80/20 Modified MediPix δ-ray?

Non Modified Modified Peter Kluit: cluster & electron density versus MC of MIP cosmic rays: single electron efficiency > 0.90 AND: Good explanation for Moire effect:pitch Micromegas holes: 60 μm pitch MediPix pixels:55 μm Periodic position of hole w.r.t. pixel: repeats after 12 pixels!

Modified Non Modified InGrid: perfect alignment of pixels and grid holes! Small pad: small capacitance!

Integrate GEM/Micromegas and pixel sensor ‘GEM’‘Micromegas’ By ‘wafer post processing’ InGrid

First InGrid expected in 2-3 weeks Wafer dia.: 100 mm 30 fields with variety of pillar geometry

INGRID: some first trials Various pitches, shapes

1.WSLC-Paris 2004: LC ready in 2015…, not known where….. 2.People with power and $: what is the relevance for LHC?! So: Other applications of TimePixGrid: - μ-TPC - upgrades of TPCs: STAR, ALICE - Transition Radiation Detectors - GOSSIP: tracker for intense radiation environment

CMOS pixel array MIP Micromegas GOSSIP: Gas On Slimmed SIlicon Pixels Drift gap: 1 mm Max drift time: 10 ns MIP CMOS pixel chip Cathode foil

Essentials of GOSSIP: Generate charge signal in gas instead of Si (e-/ions versus e-/holes) Amplify # electrons in gas (electron avalanche versus FET preamps) Then: No radiation damage in depletion layer or pixel preamp FETs No power dissipation of preamp FETs GOSSIP:1 mm gas layer + 20 μm gain gap + CMOS (digital!) chip After all: it is a TPC with 1 mm drift length (parallax!) Max. drift length: 1 mm Max. drift time: 10 ns Resolution: 0.1 mm  1 ns

Efficiency Position resolution Rate effects Ageing Radiation hardness HV breakdowns Power dissipation Material budget More details in

Conference presentations:  LCWS Paris, April (Jan T.)  IPRD Siena, May (Harry v/d G.)  IWORID Glasgow, July (Alessandro F.)  VERTEX Como, September (Harry v/d G.)  IEEE Rome, October ( Harry v/d G. ?)

Coming activities: Cosmic trigger setup ready in few weeks New Micromegas available very soon (PaulC.?) New Medipix2 available First Ingrid1 tests Simulations Longer term: Ingrid2 together with MediPix Development of Timepix1 (for TPC) and Timepix2 (for GOSSIP) CMOS chips