Alexei Onuchin, one of the pioneers of experiments at colliding beams, passed away on 9 January in Novosibirsk, Russia.
Onuchin was born in 1934 in a small village in the Gorky (Nizhny Novgorod) region. After graduating from high school with honours, he decided to try his hand at science and in 1953 he entered the physics department of Moscow State University. In 1959 he graduated with honours and was invited by Gersh Budker to work at the newly organised Institute of Nuclear Physics at Novosibirsk (INP).
At INP, Onuchin enjoyed many important roles. He took part in experiments at the world’s first electron–electron collider (VEP-1), actively worked on the preparation of a detector for the electron–positron collider VEPP-2, supervised the construction of the MD-1 detector for the VEPP-4 collider, was one of the leaders of the KEDR detector experiment at the VEPP-4M collider and was a great enthusiast of the detector project for the proposed Super Charm-Tau Factory. He was also an organiser and for many years the leader of the Budker INP group working at the BaBar experiment at SLAC.
During his career, Alexei made a great contribution to the development of experimental techniques in particle physics. It was this that determined the high level of experiments carried out at Budker INP and other laboratories. These include the development and production of multiwire proportional chambers for the MD-1, various counters based on Cherenkov radiation and the creation of a calorimeter based on liquid krypton, among many others.
Cherenkov counters held a special place in Alexei’s heart from the very beginning of his career as a student in the laboratory of Nobel-laureate Pavel Cherenkov. Starting from pioneering water-threshold counters in the experiment at VEPP–2, he later developed the MD–1 Cherenkov counters filled with ethylene pressurised to 25 bar, and finally suggested the aerogel counters with wavelength shifters (ASHIPH) now operating in the KEDR detector. For this work, in 2008 Alexei Onuchin was awarded the Cherenkov Prize of the Russian Academy of Sciences.
Alexei was a great teacher. Among his former students are professors, group leaders and members of the Russian Academy of Sciences. He was also a caring father and loving husband, who raised a large family with four children, five grandchildren and three great-grandchildren. He will always be remembered by his family, friends and colleagues.