William Frank Vinen

Abstract William Frank Vinen, known to everyone as Joe, was one of the outstanding physicists of his generation. In 1953 he joined the Royal Society Mond Laboratory as a research student, where he first investigated the propagation of temperature waves (second sound) in superfluid helium-4 in the presence of a heat current, confirming the existence of turbulent flow in the superfluid. With fellow research student Henry Hall (FRS 1982), he provided the first, albeit indirect, evidence for the existence of quantized lines of vorticity in a uniformly rotating superfluid. Joe then designed an ingenious vibrating wire experiment providing the first direct evidence for the existence of such vortices. The circulation of flow around them was quantized in the predicted units of ℎ/m4, where ℎ is Planck's constant and m4 the mass of the helium-4 atom. This was the first direct manifestation of quantum dynamics operating on a macroscopic scale, predating the confirmation of quantized lines of magnetic flux in a type-II superconductor. In 1962 he moved as a professor to University of Birmingham to set up the Condensed Matter and Low Temperature Research Group, which he led until his formal retirement in 1997. He was appointed to the Poynting chair of physics in 1973 and was head of department from 1973 to 1981. His research included pioneering experimental and theoretical investigations on the nucleation of vorticity and turbulence in superfluid helium-4, similar properties in type-II superconductors, on 2-dimensional plasmas and the Wigner crystal formed from ions held electrostatically below the surface of superfluid helium, and on light scattering at the normal to superfluid phase transition. In retirement, he continued his pioneering research on quantum fluids and turbulence until only a year before he died in 2022. His name is attached to three important equations describing flow in superfluids in the presence of vortices and turbulence. As chairman of the education committees of both the Institute of Physics and the Royal Society, he successfully persuaded the government and universities to introduce four-year undergraduate MSc courses as the norm for professional physicists.