(image: the LHC [Samuel Joseph Hertzog, CERN])
Just after 3:00 AM PT this morning, twin beams of protons once again began circulating the 27-kilometre ring of the Large Hadron Collider (LHC) at CERN, bringing to an end a three-year period of maintenance and upgrades for the collider’s next phase of data-taking. The third run of the LHC, called Run 3, will enable researchers with ATLAS and other experiments to collect data from collisions that are produced at record-high energies and unprecedented densities.
The announcement was welcomed by members of TRIUMF’s ATLAS research group, who are significantly involved in major ATLAS upgrades that support both Run 3 and future data-taking runs as part of the High-Luminosity era, including the New Small Wheel upgrade.
“This is a very exciting moment for us at TRIUMF,” said Dr. Isabel Trigger, TRIUMF Research Scientist. “Our team has been racing against the clock to help get the ATLAS New Small Wheels built, installed and commissioned in time, and now we are watching like proud parents as they take their first baby steps recording beam data. It is the biggest ATLAS construction project that TRIUMF has been part of since the original hadronic endcap calorimeters, which also received upgraded trigger electronics during the shutdown - that is being put through its paces now.”
The proton-proton collisions at the centre of the ATLAS detector produce collision debris in the form of new particles which fly out in all directions. Presently, more than a billion particle interactions take place in the ATLAS detector every second, but only one-in-a-million collisions triggers the data collection system as interesting physics and thus recorded for further analysis.
In successive runs, ATLAS will use increasingly intense beams in order to generate more very rare high energy collisions – but also more radiation, which complicates the optimization of highly sensitive particle detectors.
Higgs, history, and Hi-Lumi
The commencement of Run 3 coincides with the 10th anniversary year of the discovery of the Higgs boson, the long-elusive subatomic particle that was first glimpsed at the LHC in 2012. With more opportunities to produce and study Higgs bosons, researchers are hoping to continue pushing the boundaries of our understanding about the universe with the most stringent tests on Standard Model physics yet performed.
“The new and improved ATLAS detector will now be able to collect the largest dataset yet and possibly reveal New Physics in Run 3 data. This is exciting for TRIUMF, for Canadians, and for the entire ATLAS collaboration,” said Dr. Oliver Stelzer-Chilton, TRIUMF Research Scientist and Department Head, Particle Physics. “Through hard work during the shutdown, new capabilities in triggering and event reconstruction have been added that were not there before, which will open up exciting new opportunities. In addition, Run 3 will allow us to study the Higgs boson, which is exclusively accessible only at the LHC, in far greater detail.”
The TRIUMF ATLAS scientific group is a Canadian keystone for the participation of over one hundred Canadian researchers, graduate and undergraduate students at nine ATLAS-Canada participating universities. TRIUMF scientists, engineers and technicians have provided critical expertise to all aspects of ATLAS’ success, including detector design, data analysis, theory and large-scale scientific project management. In addition, the lab continues to provide distributed computing services as a Tier-1 data centre, one of a small number of critical global repositories for storing and processing LHC data.
(image: a TRIUMF scientist explains the ATLAS Strip Detector Upgrade for the Inner Tracker to H.E. Salome Meyer, Ambassador of Switzerland to Canada and Consul General of Switzerland in Vancouver Andreas Rufer)
The LHC’s Run 3 data-taking is expected to begin in summer 2022 and extend to 2026, after which the collider will cease operations for a three-year Long Shutdown (LS3). Leveraging planned L3 upgrades (including a made-in-Canada ‘coldbox’ technology that supports increased proton collisions), the LHC will then enter a ‘High Luminosity’ era characterized by an integrated luminosity 10 times greater than the LHC’s design value.
Today’s announcement was detailed in a press release from CERN.
To learn more about TRIUMF and the LHC, tune into the special Fireside Chat featuring TRIUMF Director Dr. Nigel Smith and CERN Director Dr. Fabiola Gianotti on April 23, 2022 via Youtube.