MPGD RD 51 Workshop Lucie de Nooij Nikhef

MPGD (RD 51) Workshop Lucie de Nooij Nikhef, Amsterdam Detector R&D group

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chronological outline when it all started to work progress made outlook

March 29, 2003 Drift Space GEM foils Medi. Pix CMOS pixel sensor Brass spacer block Printed circuit board Aluminium base plate First events, recorded on March 29, 2003. Drift space irradiated with 55 Fe quanta Gas: Ar/Methane 90/10

February 2004 And only 2 weeks later…

Nikhef/Saclay/Univ. Twente February 2004 II Very strong E-field above (CMOS) Medi. Pix! 55 Fe Cathode (drift) plane Micro. Megas Drift space: 15 mm Baseplate Medi. Pix 2 pixel sensor Brass spacer block Printed circuit board Aluminum base plate 55 Fe

Micro. Megas Timepix chip + Micromegas mesh: CERN Moiré effects + pillars Charge mode

In. Grid+Si. Prot Timepix chip + Si. Prot + Ingrid: MESA+ IMT Neuchatel “Uniform” Charge mode

Setup @ Nikhef

October 2007 • Cosmic • He i. C 4 H 10 • Fully sensitive

November 2007 • Sparks observed! • He i. C 4 H 10

April 2008 No B field of 1 T Gas: Ar/CF 4/i. C 4 H 10 : 95/3/2

Latest results

And for now Next quad: 4 chips+In. Grid on a board Re. La. Xd CO 2 cooling

What’s next? Gossip 1. 2 mm Gossip: replacement of Si tracker Essential: thin gas layer (1. 2 mm)

End of 2007 First prototype of GOSSIP on a PSI 46 working: • 1. 2 mm drift gap • Grid signal used as trigger • 30 µm layer of Si. Prot University of Nijmegen

We can see tracks! University of Nijmegen 7. 8 mm Animated GIF of 100 hits on the PSI 46 brico, 30µm Si. Prot.

Tracking material, GAS vs SILICON + it is light + primary electrons can simply be multiplied: gas amplification: low power + no bias current: low power + gas can be exchanged: no radiation damage of sensor + gas has a low εr: with small voxels the source capacity can be small (10 f. F) allowing fast, low-noise, and low-power preamps + gas is usually cheap + low sensitive for neutron and X-ray background + δ-rays can be recognized ± high ion & electron mobility: fast signals, high count rates are possible - discharges/sparks: readout system should be spark proof - ageing: must be solved and must be understood / under control ± diffusion: limits max. drift length

ATLAS update Pixel Vertex Silicon strips TRT + it is light + it is cheap + low power dissipation + high position resolution

Why not change it all? Using GEM for calormetry is studied + high energy resolution digital track counting + excellent angular resolution ± needs R&D

Questions?