Canada has been part of the ATLAS collaboration from inception:
Canadian groups built significant parts of the original ATLAS
detector, and have operated it and analyzed the data taken
since the Large Hadron Collider (LHC) turned on. To keep up with the further
increases in luminosity that will come from upgrades to the
accelerator, portions of ATLAS must be replaced during two
long shutdowns of the LHC. ATLAS Phase-I upgrades, to be installed during the 2019-20 shutdown, include replacement of the 10-metre ``small wheels'' of the
Muon Spectrometer. Canadian groups are collaborating to build
fifty of the 192 precision thin-gap chambers that will provide the
triggers for the New Small Wheels. Continuing a long involvement in ATLAS
liquid argon calorimetry, Canada is also building new
electronics to allow the trigger-level granularity of the calorimeters
to approach the full offline capability of the detector for Phase-I,
and add new digital readout electronics for Phase-II.
Phase-II upgrades will be installed during the final long shutdown (around 2024-26) before full High-Luminosity LHC (HL-LHC) operation at five to seven times the nominal design luminosity. Canadians are also participating in the
Phase-II replacement of the entire inner tracking detector of ATLAS with an all-silicon tracker (ITk) consisting of both pixels and strips. Canada proposes to
build a significant fraction of the endcap strips detector.
The talk will describe these efforts in the context of the
overall upgrade goals for Phases I and II.