My friend Paul McDonald, who has died aged 74, was a physicist and expert in cryogenics whose work advanced a variety of technologies, including satellite tracking, superconducting magnets and cryostat thermometers. He was also a keen supporter of Cruisewatch, the protest group that tracked cruise missile convoys at Greenham Common, Berkshire, in the 1980s.
Born in Salford, Paul was the eldest son of Frank McDonald, a PoW survivor of the Burma Railway, and Elsie (nee Rosser), who had nursed Frank back to life in the Tropical Medicine hospital, Liverpool.
Paul studied physics at Lancaster University, graduating in 1969. He then went to work at Oxford Instruments, designing and developing superconducting magnets. He did an MSc in cryogenics in 1975 and was awarded his PhD from University of Southampton in 2002.
In his 20s, Paul installed cryogenic apparatus in laboratories around the world and by the age of 30 was in the team to design the world’s first 500Mhz nuclear magnetic resonance superconducting magnet. It gained a Queen’s Award for Industry.
In 1972 he met Di Smith in Oxford, and they married two years later.
In 1982 Paul joined the Institute of Cryogenics at Southampton University, to head its Cryogenic Advisory Unit, which put its technologies to a wide range of uses. In satellite technology, Paul’s expertise in early dry-cooling equipment helped to improve large antenna dishes for deep space exploration. He was also involved in a start-up creating calibrated silicon diode thermometers, used to measure very low temperatures, much in demand in industry. He was also an adviser for cryogenic safety manuals.
Soon after Paul’s move to Southampton, US cruise missiles were stationed at Greenham Common and the women’s peace camp and Cruisewatch entered Paul’s world. Di was at the camp during the evictions of 1984. Paul supported Di in all her peace efforts. With other young academics turned protesters, Paul repaired Cruisewatch vehicles in the front garden after they had been damaged in clashes with the convoys’ police escorts. All the while he was bringing six children and remaining fully engaged with his scientific work.
Paul was a warm, kind person who in his own gentle way had a strong presence. He wore his intellect and gifts very lightly – putting them to good use in whatever was needed of him, whether plumbing at home or singing tenor with Southampton Philharmonic Society for 25 years.
Paul was a fellow of the Institute of Physics, a chartered physicist, and an active member of the British Cryogenic Council, Institute of Refrigeration and Scientists for Global Responsibility.
He retired from full-time work in 2010, continuing part-time until 2012.
Paul is survived by Di and their children, Eleanor, Joel and triplets Alexandra, Bethan and Sophia. Their eldest son, Matthew, died in 2004.