Irene started work at CERN as a PhD student of the University of Athens with the West Area Omega experiment. From 1993, she worked with the ATLAS LAr calorimeter group from LAL Orsay, participating in calorimeter prototype beam tests and doing ATLAS’s first full simulation of photon and electron identification by calorimeters.
In 1996, Irene joined the ATLAS Tile calorimeter community, and was a very active member of the collaboration from then on, initially working with the IFAE Barcelona team. She was involved in the first prototypes of caesium radioactive source calibration systems, optimising the optical uniformity of the Tile calorimeter.
In the year 2000, Irene joined the University of Athens team at ATLAS. She worked on commissioning an important test bench to qualify the 10,000 photo-multiplier blocks assembled for the ATLAS Tile calorimeter, and was also involved in the quality checks of the early production Tile calorimeter modules.
Finally, in 2004, Irene Vichou joined the University of Illinois at Urbana-Champaign, and became actively involved in the preparation phase for Tile calorimeter sub-detector operation at the ATLAS experiment. She was responsible for many crucial hardware activities and worked in parallel on the final refinement of the cell electron energy scale from test beam data, offline data quality, studies of coherent noise and saturated pulses. At the global level of the ATLAS experiment, Irene coordinated several activities within the Jet/Etmiss group.
Irene was a supervisor of several PhD students, who were studying the cross sections of ttbar production in the dilepton channel with ATLAS 7 TeV data. She was a real mentor and friendly example to follow for them.
From 2014, Irene was the Project Leader of the ATLAS Tile calorimeter system. Under her lead, the project underwent a major front-end electronics consolidation and repair campaign during the long shutdown after LHC Run 1. This allowed a fully working detector to be in place by the start of Run 2, which was more robust against possible failures, thus improving the quality of the experimental data. The Tile calorimeter upgrade R&D and test activities for the High Luminosity LHC took a huge step forward under her supervision.
Irene was a calm and thoughtful colleague and a good friend to many of us in ATLAS. She was a genuinely nice person to all those with whom she interacted, and we are struggling to come to terms with her passing. She always looked carefully and deeply into every topic, and earned everyone's appreciation and respect along the way. We came to rely on her calmness, quiet wisdom and authority in all Tile calorimeter matters and beyond.
Many messages of condolence have come from right across the Collaboration - meaning from across the globe - universally reflecting the huge respect and friendship everyone held for Irene. We will all miss her dearly.
Our thoughts are with Irene’s husband Ilias and their daughters Paulina and Natalia.
Her friends and colleagues in ATLAS