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This paper discusses the rationale of fast neutron therapy and presents some early results obtained at the Medical Research Council's Cyclotron Unit at Hammersmith Hospital, London. The importance of the oxygen enhancement ratio for fast neutrons is considered, together with the significance of the small proportion of anoxic cells present in most tumours. The significant features of the preliminary results obtained in patients with malignant disease are presented and the characteristics of fast neutron beams for radiotherapy are discussed.

After 20 years of operation as a conventional synchrocyclotron producing 0.4 ?A time average internal beam current of protons (increased to 1.6 ?A in 1967) of ~ 385 MeV, we stopped operation in September 1970 for the major modification for which we have been planning since 1965. The major study program and the conversion project are supported by a $ 3.9 M grant from the NSF. The conversion retains the basic cyclotron magnet (2000 tons of Fe and ~ 300 tons of Cu coils), but adds a 10-in. thick Fe band around the outside magnet perimeter to lower the return path reluctance. A new larger vacuum chamber is used, with auxilliary excitation coils. Pole iron within 30 in. of the median plane is replaced by a new configuration which includes N=3 symmetry sector iron with a small median plane gap. = 18 kG near the center and 20 kG near 80 in. radius. Strong azimuthal magnetic field flutter begins at < 2 in. radius to give strong focusing ?z, and ?r?1. We expect to obtain ~ 550 MeV proton energy, with high extraction efficiency for a 10 to 40 ?A time average external beam (~ 50% duty factor), when operation starts later this year. Additional details are given in companion papers in these Proceedings. The system will still be a synchrocyclotron and will have a 300 Hz FM repetition rate, with a new RF system, etc.

This paper discusses some aspects of the superconductivity of rare‐earths and actinides :1) The pressure dependence of the superconductivity of Lanthanum is explained under the assumption of a valency a little smaller than 3. Some new experimental evidences could support this assumption. Superconductivity of Cerium metal and alloys is briefly reviewed.2) A simple model for actinides metals and alloys is presented for explaining the occurrence of localized magnetism only for Curium and the superconductivity of actinides impurities in Lanthanum.

The nonspherical or angle dependent part of the intermolecular potential can be studied by a variety of experimental techniques which give direct information about the nonspherical interaction between molecules. In this paper an attempt is made to assess information available on the angle dependent part of the intermolecular potential obtained from acoustical relaxation, NMR, depolarized Rayleigh scattering, flow birefringence, field effects on transport properties of gases and pressure broadening. This information, obtained for simple polyatomic molecules such as N2, CO, H2, HD and CH4, is tabulated as effective cross sections which are matrix elements of a collision operator. The results are discussed from two points of view: the experimentally observed trends which the cross sections tend to follow; the ability of theory to agree and predict such trends and to find relationships between cross sections.

The paper contains a brief account of measurements of thermal conductivity which have been performed by the transient hot wire method at atmospheric pressure and in the temperature range 55–195°C. The measurements were performed on He, Ne, Ar, Kr, N2 and CO2. In the case of the noble gases, the measurements prove to be thermodynamically consistent with the measurements of viscosity performed by R. DiPippo and J. Kestin. This agreement is secured with a margin of error which does not exceed 0.9%. The accuracy of the measurements is estimated to be one of 0.3%.

We must understand the physics of strongly interacting electrons if we are to have a fundamental understanding of magnetism. This paper treats the simplest model with this property — the Hubbard model. The moments of the spectral weight function (SWF), derived by Harris and Lange, are calculated in the atomic limit. These moments are used to generate an approximate SWF (including lifetime effects). The paramagnetic and ferromagnetic ground state energies are calculated and compared. There is no restriction on the electron density.