Why Micromegas? Muon Upgrade Workshop, 27/01/2012 Jörg Wotschack

In short Single device for trigger, precision & 2nd coordinate Best performance Simplest and most elegant trigger scheme Safest for high rates Most ‘friendly’ operating parameters (gas, HV) Easiest to build, commission, install, and maintain Lowest costs for production, operation, and maintenance Muon Upgrade Workshop, 27/01/2012 Jörg Wotschack

Performance Best space resolution Only detector(of those proposed) that achieves a double track resolution of O(mm) Finest granularity, therefore superior track reconstruction Track vectors in single plane, a very powerful tool for pattern recognition and track reconstruction Lowest sensitivity to cavern background (1/3 x MDT), another factor in favour of MMs Muon Upgrade Workshop, 27/01/2012 Jörg Wotschack

Trigger Trigger granularity is a single strip, i.e. 0.5 mm (out of 64 strips or 32 mm) Four strip addresses per chamber plane are transmitted to USA15 every bunch crossing (25 ns) Trigger decision by track matching algorithm in look-up table or FPGA Proposed scheme avoids processing on SW other than in front-end chip the trigger info is routed through the same fibre that is used for the data transmission to USA15 trigger processing electronics is accessible during running (in contrast, the TGC and RPC concepts need an on-chamber majority decision; electronics not accessible during a full year) Look-up memories or FPGAs can be reprogrammed if required Muon Upgrade Workshop, 27/01/2012 Jörg Wotschack

Safe a high rates Far from critical rates, even at 15 kHz/cm2 Large safety margin if LHC luminosity would go up further or background rate increases MMs are still operating fine at MHz/cm2 and above (trigger concept would need to be adapted, e.g. more fibres/plane in high rate regions) No ageing observed in high-rate X-ray and neutron exposures (10-20 years of sLHC) Long-time behaviour of resistive strips needs to be demonstrated; same holds for RPCs and TGCs for resistive coatings Muon Upgrade Workshop, 27/01/2012 Jörg Wotschack

Operation and maintenance MMs require only half of the services that are needed by the other proposals No on-chamber trigger processing electronics Most ‘friendly’ operating parameters Low HV (500 V) Inert and cheap gas, Ar:CO2 (93:7), at atmospheric pressure Lowest costs for operation and maintenance Muon Upgrade Workshop, 27/01/2012 Jörg Wotschack

Construction & commissioning Industrial production of MMs (employing commercial equipment) using PCB technology Assembly, commissioning, and testing in/by collaborating institutes. Simple mechanics & assembly No glueing of components, easy opening and replacement of detectors if required Most cost effective of the three proposals half the number of chambers, half of the electronics half of the manpower and infrastructure for testing and commissioning Muon Upgrade Workshop, 27/01/2012 Jörg Wotschack

In conclusion Single device for trigger, precision & 2nd coordinate Best performance Simplest and most elegant trigger scheme Safest for high rates Most ‘friendly’ operating parameters (gas, HV) Easiest to build, commission, install, and maintain Lowest costs Why would one not choose micromegas ??? Muon Upgrade Workshop, 27/01/2012 Jörg Wotschack