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

2. 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

3. 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

4. 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

5. 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

6. 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

7. 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

8. 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