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 when it all started to work  progress made  outlook

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

And only 2 weeks later…

Very strong E-field above (CMOS) MediPix! MediPix2 pixel sensor Brass spacer block Printed circuit board Aluminum base plate MicroMegas Cathode (drift) plane 55 Fe Baseplate Drift space: 15 mm 55 Fe Nikhef/Saclay/Univ. Twente February 2004 II

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

Timepix chip + SiProt + Ingrid: “Uniform” MESA+ IMT Neuchatel Charge mode

Cosmic He iC 4 H 10 Fully sensitive

Sparks observed! He iC 4 H 10

No B fieldB field of 1 T Gas: Ar/CF 4 /iC 4 H 10 : 95/3/2

 Next quad: 4 chips+InGrid on a board  ReLaXd CO 2 cooling

1.2 mm Gossip: replacement of Si tracker Essential: thin gas layer (1.2 mm)

First prototype of GOSSIP on a PSI46 working: 1.2 mm drift gap Grid signal used as trigger 30 µm layer of SiProt End of 2007 University of Nijmegen

Animated GIF of 100 hits on the PSI46 brico, 30µm SiProt. 8mm 7.8mm We can see tracks ! University of Nijmegen

+ it is light + primary electrons can simply be multiplied: gas amplification: low power Tracking material, GAS vs SILICON + no bias current: low power + gas can be exchanged: no radiation damage of sensor + gas has a low ε r : with small voxels the source capacity can be small (10 fF) 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

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

Using GEM for calormetry is studied + high energy resolution digital track counting + excellent angular resolution ± needs R&D

Questions?