Direct photon emission observed in nucleus-nucleus collisions at intermediate beam energies (0.3 ⩽ β ⩽ 0.4) shows some very interesting features, especially when comparing it to pion production in such collisions. Valuable information is gained through the fit of a standard black-body radiation formula to the data as well as by a comparison to classical bremsstrahlung theory. A photon production in the early phase of the collision is indicated; in the bremsstrahlung picture this corresponds to a rather sudden slowing down of the relative motion.

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Target-like reaction products corresponding to the transfer of one or several nucleons have been measured as a function of the total kinetic energy loss in the reactions Pb+' Ni (1215 MeV) and Pb+ Ni (1107 MeV) with a focusing time-of-flight spectrometer which provided a unique mass and charge separation and good energy resolution. The analysis of the experimental data covered the range from elastic scattering to deep-inelastic collisions. In the quasielastic region, neutron transfer dominates. The transfer probabilities as a function of the distance of closest approach can be described by a semiclassical theory of tunneling. Quasielastic transfer from the Ni targets to the 0 Pb projectile is strongly inhibited by the reaction Q values. For the intermediate and deepinelastic collisions, the mean values and variances of the mass and charge distributions as a function of the dissipated energy, as well as the correlations between neutron and proton transport, are discussed in a statistical diffusion theory. The important influence of the static potential energy surface on nucleon transport in the deep-inelastic region is demonstrated. Deviations from the simple diffusion model, observed at small to medium energy losses, are discussed.

For the first time polycrystalline silicon has been grown by using the visible light of an Ar+ laser for pyrolytical decomposition of SiH4. With a laser irradiance of 3600 W/mm2 a deposition rate of 30 μm/s was obtained. The temperature dependence of the deposition rate was investigated. The kinetically controlled regime is characterized by an activation energy of 44±4 kcal/mole.