The Copley Medal is awarded to Sir Nevill Mott, F.R.S. At an early stage in his career Mott had already established a reputation as a pioneer in the field of atomic collision theory based on the new wave mechanics. He was the first to show that Rutherford’s scattering law remains exactly valid when this mechanics is employed, and to point out the importance of symmetry in scattering problems. He was also the first to apply Dirac’s relativistic theory to these problems and showed that under certain conditions electrons may be polarized by double scattering. Even as early as 1932 he realized the importance of conservation laws in limiting reaction cross sections. All of this work was characterized by a remarkable degree of originality and physical insight combined with mathematical skill. When, at the age of 27, he became professor of theoretical physics at Bristol, he abandoned the study of atomic collisions to work on the theory of metals and alloys, in order that he might relate his work more closely to that of a new group of experimenters. Within a few years he was recognized as one of the leading international authorities in this field, to which he contributed a number of important papers on electronic bands in metals and on the electrical conductivity of alloys and its temperature coefficient.
Charge Exchange Reactions in Astrophysical Plasmas
