Since the liquefaction of helium in 1908 in Leiden by Kamerlingh Onnes, Canadian researchers have played a major role in unraveling the mysteries of this amazing liquid. This started with liquifying helium at Toronto in 1923 by Shrum and McLennan. In 1938, Allen and Misener, working at Cambridge University, reported the dramatic discovery of zero viscosity below 2.18 K. This seminal discovery led to the realization (by London, Tisza and Landau) that helium was a superfluid "quantum liquid", which exhibited macroscopic quantum effects. In the period 1955-1970, pioneering measurements on the atomic dynamics of superfluid helium were made at AECL in Chalk River by Hurst, Henshaw, Woods, Cowley and Svensson, including the phonon-roton excitation energy and the Bose condensate fraction. Their work is a jewel in the crown of Canadiian research.
Host: Elisabeth Nicol