Canada has a strong intermediate-energy laboratory, the TRIUMF National Laboratory for Particle and Nuclear Physics, and a successful underground laboratory, the Sudbury Neutrino Observatory Laboratory (SNOLAB). In the past its HEP community has been carrying out experiments in the US as well as in Europe, notably the OPAL experiment at LEP.
An International Cooperation Agreement (ICA) and two Protocols were signed between CERN and TRIUMF in 1996.
Via the National Research Council Canada (NRC), with funding through TRIUMF, Canada made important contributions to the LHC warm insertions and injection lines.
Canadian scientists are contributing in a substantial way to the ATLAS experiment, with funding from the Natural Sciences and Engineering Research Council of Canada (NSERC). Canadian activities in particle physics are coordinated through the national Institute of Particle Physics.
Canada is contributing to the Worldwide LHC Computing Grid (WLCG) via a Tier-1 centre at TRIUMF and two Tier-2 centres funded by the Canadian Foundation for Innovation (CFI). In 2018, TRIUMF's Tier-1 centre was transferred to Compute Canada's new state-of-the-art facility at Simon Fraser University.
In 2009, a new agreement was signed to define the framework of the contribution by TRIUMF to the upgrade of the CERN accelerators. Canada is contributing to the construction of the cryomodules that will house the crab cavities for the HL-LHC. Addenda to the Protocols with TRIUMF on collaboration on the HL-LHC and on rare-isotope beams have been concluded in 2017 and 2019. In 2017, the Canadian Light Source (CLS) joined the CLIC/CTF3 Collaboration, while in 2018 both the CLS and the University of Saskatchewan joined the FCC.
Canada also participates in several non-LHC experiments, such as ALPHA, ATRAP, CAST and ISOLDE. There is also on-going intensification of collaboration with SNOLAB in the area of liquid argon detectors for dark-matter experiments.