Physicist Ian Shipsey, who has died suddenly aged 65, developed silicon devices with exquisite precision to study the debris of subatomic particle collisions and light from the edge of the universe. Using these devices, he played a major role in unlocking the secrets of the earliest fractions of a second of our universe.
Silicon devices also played an important role in his everyday life. Profoundly deaf after treatment for leukemia in 1989, he received a cochlear implant 12 years later that enabled him to develop strategies to overcome this disability, to the extent that it often went unnoticed by interlocutors .
Ian thought deeply about physics and was always looking for the key questions to advance our understanding. He not only asked the right questions, but developed the detectors to answer them. He started experiments and techniques on different types of facilities in particle physics, including electron-positron annihilation at Cornell University in the USA for two decades from the mid-80s and the collisions of protons at the Large Hadron Collider (LHC) at Cernin Geneva, from the mid-2000s.
While he remains one of the leaders of LHC experimentation to this day, he also devised new silicon detectors to isolate extraordinarily rare decays of the muon, the electron’s heavier sister particle.
Ian was always looking for applications of the instrumentation he developed outside of particle physics and led the application of silicon detectors to record light from the most distant visible objects in the universe. He was a pioneer in both the US and then in the UK of the Vera C Rubin Observatory LSST camera, the largest astronomical camera ever built, which is about to become operational in Chile after a 20-year construction period. It will look for clues to the nature of the dark energy that makes up most of the universe.
Towards the end of his career, Ian saw the potential of devices based on quantum entanglement – in which entities that obey the laws of quantum dynamics, such as atoms or photons, retain an interdependence even when widely separated—to address fundamental questions in science and computing. He has led several major new initiatives to success in highly competitive funding initiatives.
Born in Walthamstow, north-east London, Ian was the son of Mary (née Barrett) and Edward Shipsey. From Cardinal Wiseman Senior High School he went to what is now Queen Mary University of London, where he graduated in physics (1982). The first in his family to attend university, he took a break after starting his studies and spent a year working for the Cyrenians, a charity for some homeless people.
Ian started research for his PhD at the University of Edinburgh doing an experiment at CernNA31, who investigated decay of kaon particles. It gives information about small asymmetries in the laws of particle physics that may explain why the visible universe consists of matter, without substantial antimatter. While at Cern, Ian met Daniela Bortolleto, a fellow physicist. They married in 1988 and maintained a lifelong collaboration both personally and in physics.
After receiving his PhD in 1986, Ian moved to the USA, first to Syracuse University, New York, where he joined Daniela as she studied for her PhD, and then in 1990 to Purdue University, Indiana, where both obtained tenure.
Ian became a leader of the Cleo experiment, which studied the parameters that determine, among other things, the properties of the “CP violation”, and established a distinction between matter and antimatter, which he first studied at Cern, but now in particles containing heavy quarks. In 2001, he was elected leader of Cleo for three terms, and he built his first silicon detector for the project.
It was as a pioneer in silicon detectors that Ian made his mark on LHC, first through his work on one of its detectors, the CMS, while in the US, and then, after moving to Oxford University in 2014, on CMS’s sister experiment, Atlas. Ian also made important contributions to physics analysis; at CMS on aspects of the quark-gluon plasma and at Atlas in studies of the properties of the Higgs boson.
Ian transferred his detector development laboratory to Oxford and established a state-of-the-art silicon detector manufacturing facility with Daniela. At the time of his death, he was deeply involved in the construction of upgraded Atlas silicon detectors.
In addition to this enormous load of research, Ian was a dynamic head of the physics department at Oxford as Henry Moseley Centenary Professor of Experimental Physics. His enthusiasm has inspired more than 100 faculty members to new heights of achievement.
Ian was in great demand as a referee and adviser on international activities. His transparent scrupulous fairness led him to be elected to many positions by his peers. He was proud, as a naturalized American, to be elected chairman of the section of particles and fields of the American Physical Society, of which he was a fellow.
He was awarded the James Chadwick Medal from the Institute of Physics in 2019 and was elected a Fellow of the Royal Society in 2022.
She and Daniela’s woodland home near Purdue was a center of laughter and hospitality for many friends and colleagues. He told the story of his triumph over his deafness and the redemptive nature of cochlear implants in a lecture he gave many times around the world. A decade ago it moved the audience at the Oxford May Music Festival, which I organize to bring together music, science and the arts.
Ian is survived by Daniela and their daughter, Francesca.
