Calendar: 1962-1963 Page 433

xliv ANNUAL REPORT indirectly with the central problem of molecular biology the mechan- ism of protein synthesis The spectroscopy group under the direction of Professor Price developed equipment covering wide range of the electromagnetic spectrum from the extreme infra-red to the far ultra-violet including electron spin resonance thus enabling the research problems of the group to be investigated in more comprehensive manner than had been hitherto possible This technically advanced equipment was used in studies of the solid state for which the intrinsic as well as the impurity properties were investigated High-pressure 20 000 atmospheres and low-temperature liquid helium facilities were applied in conjunction with the spectroscopic studies to give information about interactions in condensed phases Photoionization and spectroscopic investigations on gaseous molecules have led to new ideas of fundamental importance con- cerning the effect of π electrons on the shapes and properties of radicals and molecules The spectroscopy group presented three papers at the European Spectroscopy Congress in Amsterdam The solid state group under the direction of Professor Champion continued their work on the optical and electrical properties of diamonds and produced strong evidence for the existence of excitons in energy transport in diamond The group also demonstrated the nature of impurities in diamond for the first time by radioactive neutron activa- tion contract to work on uranium oxide which has similar crystal structure to diamond was arranged with the Atomic Energy Authority Most of the research of the theoretical group led by Professor Domb continued to centre on the statistical mechanics of interacting systems but interest was also maintained in the properties of the solidi- fied inert gases and the dynamics of ordered and disordered lattices The techniques which were developed for the theory of co-operative phenomena found useful application to problems connected with the configurations of polymer molecules and one session of the Conference of the Physical Society at Bristol in January on Physics of Polymers יי was devoted to the work of the theoretical group Two significant new results obtained this year were an exact solution of classic problem of dimer configurations on lattice by Dr Μ Fisher in collaboration with Dr Η Ν Temperley and an analysis of the ground state of an antiferromagnet for the Ising lattice by Dr Danielian An unusually large number of nine students decided to take the Theoretical Option for Part II Special this year Of these five secured Firsts and three Upper Seconds The nuclear physics group led by Dr Burge continued its work with 10- and 30-MeV protons at Harwell Preliminary measurements of the total reaction cross-section for carbon were com- pleted and tests made on the scintillations from liquid argon The apparatus for elastic and inelastic scattering was further developed and foil of water was used as target as an introduction to studies of free liquid targets including liquefied gases The theoretical study of