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Stefano Colafranceschi
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Construction of GEM detectors for the CMS forward muon upgrade
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The High-Luminosity (HL-LHC) upgrade of the
LHC features an increase of the background
rate (at the higher η regions) up to
1 kHz/cm2. In this condition it will be challenging,
for the present muon system, to provide an
acceptable L1 trigger rate for muons with
pT < 25 GeV, without increasing the threshold
on muons. To overcome this, the CMS Collaboration
decided to renovate the muon system, upgrading
the already existing stations, while installing
new GEM detectors by 2019. While the CMS
Collaboration has been developing large-area
GEM detectors since many years, in 2016 ten
pre-production detectors were assembled,
delivered, installed and operated at CMS.
During 2017 the CERN, together with several
external assembly sites, have established
detector production lines to assemble and
validate all detectors required to instrument
the new endcap station.

We discuss preliminary results about the
pre-production detectors installed and operated
at CMS and the detector mass production established
at CERN/assembly sites. Specifically, we
will detail all the quality controls we agreed
upon, to monitor and control the mass production.

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