| AdminHistory | When Hitler came to power Simon decided to leave Germany although, as a war veteran and holder of the Iron Cross first class, he was exempt from the decree dismissing Jews from university posts. He correctly foresaw the trend of events and in August 1933, at the invitation of FA Lindemann (later Viscount Cherwell), he moved to the Clarendon Laboratory in Oxford on one of the research grants provided by Imperial Chemical Industries for refugee scientists from Germany. He became reader in thermodynamics in 1936 and was accorded the title of professor and became a student of Christ Church in 1945; in 1949 a chair of thermodynamics was specially created for him. In Britain he was to be known as Francis, though Franz remained his formal name.
The Clarendon Laboratory when Simon came to it was small and not too well equipped, but the period of 1933-9 was nevertheless rich in achievements. The magnetic cooling method to reach temperatures down to 0.001 °K, proposed in 1926 by Debye and by Giauque, fascinated Simon, who had earlier carried out experiments to estimate the scope of the method and now devoted much of his energy to developing it as a practical technique for experimenting in an entirely new temperature range. This work, carried out with a small group of collaborators, led to the discovery of new superconductors and new magnetic phenomena in paramagnetic substances and included experiments on thermal conductivity and thermal relaxation. It was during the same period that experiments with helium II (the 'superfluid' low temperature modification of liquid helium) led Simon to postulate the existence of a mobile helium II film on all surfaces in contact with the liquid.
The outbreak of war in 1939 brought this research work to an end. Simon, a naturalized British subject since 1938, tried hard to contribute to the war effort but there was reluctance to entrust secret work to ex-enemy aliens. With other refugee scientists, notably Rudolf Peierls and Otto Frisch, he became interested in the possibility of an atomic bomb and began to work on the problem before it had become an official project: hence the paradoxical fact that in its early days the 'Tube Alloys' project (as the British atom bomb project was code-named) was run mainly by foreign-born scientists. Simon was mainly concerned with the separation of the uranium isotopes by the gaseous diffusion method and his report in late 1940 contained the first realistic proposal for a sizeable separation plant. He was also involved in many other aspects of atomic energy and his stimulating views played a part in Britain's atomic energy developments both during and after the war. ('Sir Francis Simon', by Nicholas Kurti, Oxford Dictionary of National Biography).
The low temperature team, now considerably larger than in pre-war days, was about to begin the work which established it as one of the most important low temperature schools in the world. Simon had not the time to concern himself actively with many of the projects undetaken, but those that had been his lifelong interest - experiments conected with specific heats, very high pressure and the melting curve - he followed keenly, and he was personally responsible for initiating the work on heat conductivity. His greatest interest during the post-war years was in nuclear orientation and in particular nuclear cooling. (From Nancy Arms <i>A Prophet in Two Countries - A Life of FE Simon</i>, pp134) |