As final preparations were made for the start of the Large Hadron Collider's (LHC) Run 2, the ATLAS Control Room was the centre of activity. Here are images from the three days that were landmark events -- first collisions at 900 GeV on 5 May, first test collisions at 13 TeV on 20 May , and 3 June that marked the beginning of physics data-taking at 13 TeV and ATLAS' journey into unexplored frontiers of physics.
5 May: Physicists in the ATLAS Control Room prepare for the first scheduled proton beam collisions to be delivered by the Large Hadron Collider. The beams collided at injection energy or 900 GeV (one proton has a mass of about 1 GeV). (Image: Silvia Biondi / ATLAS Collaboration)
5 May: ATLAS people on shift that morning wait for the LHC Control Room to signal injection of beam. (Image: Silvia Biondi / ATLAS Collaboration)
5 May: ATLAS Run Coordinator Alessandro Polini (left) shares a smile with Spokesperson Dave Charlton as they wait for 900 GeV collisions. (Image: Matteo Franchini / ATLAS Experiment)
5 May: The LHC beam being monitored on one of the many control room desktop monitors. (Image: Silvia Biondi / ATLAS Collaboration)
5 May: A physicist on shift watches as the first collisions at injection energy or 900 GeV burst on the wall of screens in the ATLAS Control Room. (Image: Silvia Biondi / ATLAS Collaboration)
6 May: Display of a proton collision event recorded by ATLAS at 900 GeV or injection energy. Tracks are reconstructed from hits in the inner tracking detector, including the new innermost pixel detector layer, the Insertable B-Layer. (Image: ATLAS Collaboration)
On 20 May, at 22:24, ATLAS recorded the first 13 TeV test collisions delivered by the Large Hadron Collider. The proton collisions set a new high energy record. (Image: Heinz Pernegger / ATLAS Experiment)
1 May: Display of a proton collision event recorded by ATLAS at 13 TeV collision energy. Tracks reconstructed from hits in the inner tracking detector are shown to originate from two interaction points, indicating a pile-up event. (Image: ATLAS Collaboration)
3 June: Morning light shines of the mural of a simulated event in the ATLAS detector. This image was taken on the morning when physics data-taking was scheduled to start. The mural is painted on the building that houses the ATLAS Control Room. 100m directly below the building is the cavern where the ATLAS detector sits on the Swiss side of the LHC. (Image: Clara Nellist / ATLAS Collaboration)
3 June: Inside the Control Room as final adjustments and preparations for 13 TeV collisions with stable beams are being made to record physics data. (Image: Silvia Biondi / ATLAS Collaboration)
3 June: ATLAS physicists gather inside the Control Room to witness the start of the physics data taking at 13 TeV with the ATLAS detector. (Image: Silvia Biondi / ATLAS Collaboration)
3 June: ATLAS Run Coordinator Alex Cerri and Central Trigger Processing expert Julian Glatzer looking at plots that describe proton bunch groups from the LHC. Each LHC orbit has around 3,564 proton bunches spaced at every 25 nanoseconds to fill the 27 km ring. (Image: Silvia Biondi / ATLAS Collaboration)
3 June: Readying for that moment when ATLAS began recording 13 TeV collision data. (Image: P. Descombes / CERN)
3 June: Display of a proton collision event recorded by ATLAS with first LHC stable beams at a collision energy of 13 TeV. Tracks reconstructed by the tracking detector are shown as light blue lines, and hits in the layers of the silicon tracking detector are shown as colored filled circles. The four inner layers are part of the silicon pixel detector and the four outer layers are part of the silicon strip detector. The layer closest to the beam, is the IBL, installed during the LHC shut down. (Image: ATLAS Collaboration)
3 June: The Control Room bursts into applause as ATLAS begins recording data. (Image: Emma Ward / ATLAS Collaboration)
3 June: (From left) Run Coordinator Alex Cerri, Technical Coordinator Ludovico Pontecorvo, Spokesperson Dave Charlton and Run Coordinator Alessandro Polini raise a toast to the start of LHC Run 2 and ATLAS' smooth operation. (Image: Clara Nellist / ATLAS Experiment)
For the next three years, ATLAS will collect collision data and look both broadly and deeply into it to see what nature may have in store for us. (Image: Clara Nellist / ATLAS Collaboration)
