Jan Beenakker
Joannes Joseph Maria Beenakker, more often known as Jan J. M. Beenakker or Jan Beenakker, was a Dutch physicist and the rector of the Leiden University.
Education and career
Beenakker was the son of a railway employee and grew up in Zeeland and Rotterdam. In 1942 he obtained his Abitur, but because of the Second World War he was only able to start studying physics at Leiden University in 1945. In 1951, after intermittent military service, he received his diploma in meteorology and in 1954 he received his doctorate in low temperature physics from Cornelis Jacobus Gorter and Krijn Wybren Taconis from the Kamerlingh-Onnes Laboratory at Leiden University. His dissertation was on the influence of the helium-3 isotope on superconductivity. Beenakker remained in Leiden after graduation, where he became a lecturer in 1959 and a full professor of experimental physics in 1963. From 1985 until his retirement in 1991 he was rector magnificus of the Leiden University. Between 1969 and 1970, Beenakker was on sabbatical at the Massachusetts Institute of Technology. Between 1961 and 1962 visiting professor at the KU Leuven.Research
His research dealt with the thermodynamic and transport properties of liquids and gases. The Senftleben-Beenakker effects are named after him and the German physicist Hermann Senftleben, which describe the influence of electric and magnetic fields on the transport properties of molecular gases. It bears a distant resemblance to the Hall effect in solids. From earlier experiments by Senftleben it was believed that this only affected paramagnetic molecules such as nitric oxide and oxygen, but Beenakker and his colleague Hein Knaap showed that diamagnetic gases such as nitrogen and methane are also affected by external fields, since the precession rate between two collisions of the molecules is changed by them.Beenakker also studied transport in highly diluted gases, in which boundary layer phenomena play a role and new phenomena emerge. With colleagues, he was the first to observe the non-equilibrium velocity distribution in a heat-conducting gas.