Papers of the Nikko, Japan meeting of June 1991, on sub-barrier fusion, orbiting and fusion-fission phenomena, direct reaction approaches, fission decay and collective dynamics of hot nuclei, microcluster impact fusion, maximum excitation energy and angular momentum of hot nuclei, super heavy elemen

The field of nuclear dynamics has evolved tremendously over the course of the 15 years of this workshop series. The workshop presently spans a very broad range of research interests. These include the development of concepts that will form the foundation of research for the quark-gluon plasma as well as current studies of very hot and dense baryonic matter through the measurement of pions, strange particles, dileptons, baryons and antimatter. The investigation of the decay of extremely hot nuclear systems blossomed with the dramatic observation of multifragmentation of heavy systems and detailed studies of the temporal and spatial extent of the system emitting fragments at a wide range of excitation energies. This also includes a continuing search for the liquid-gas phase transition in nuclear matter. An entirely new field of inquiry has begun with the advent of reaction studies with radioactive beams.This international workshop, attended by theorists and experimentalists from 20 institutions and 6 countries, continues to provide the opportunity for cross-fertilization between researchers involved in the broad range of research in nuclear dynamics as well as stimulating the interaction between experimentalists and theorists. The present status of research in the vigorous field of nuclear dynamics is reviewed.

The ASI 'Topics in Atomic and Nuclear Collisions' was organized in Predeal from August 31 to September 11. It brought together people with a broad interest in Atomic and Nuclear Physics from several research institutes and universities in Ro mania and 16 other countries. The school continues a tradition that started on a small scale back in 1968, fo cussing mainly on current problems in nuclear physics. Though the organizing of this edition started very late and in very uncertain economic and financial conditions, it turned out to be the largest meeting of this type ever organized in Romania, both in topics and participation. There were many applicants for participation and grants, considerably more than could be handled. The selection made by the local organizing committee was based on the following criteria: a proper balance of atomic and nuclear physicists, a broad representation of people from Research Institutes and Universities, a balanced par ticipat!on with respect to age, sex, nationality and observance of ASI requirements.

The proceedings focuses on the recent developments in the physics of unstable nuclei. The topics include: masses and radii of exotic nuclei, structure and decay of unstable nuclei, neutron-halo and excitations of neutron drip-line nuclei, new aspects of reaction dynamics induced by exotic nuclear projectiles, production and reactions of radioactive nuclear beams, and synthesis of superheavy elements.

This book reviews recent developments in the field of superheavy elements and the related phenomena of fission, cluster radioactivity, and drip line physics. Both the experimental and theoretical aspects are dealt with in detail. For the production of new elements in the laboratory, the process of cold compound nucleus formation is found to be most favorable both theoretically and experimentally. However, experimentally, hot fusion of nuclei has also been used. Both the physical and chemical methods of synthesizing new elements are discussed. The theoretical approaches considered here are those of the quantum-mechanical fragmentation theory, the self-consistent Hartree-Fock theory, and the relativistic mean field theory. Fission, a process inverse to the fusion of two nuclei, is also observed to be most favourably a cold phenomenon. Other important results are bi-modal fission and high n-multiplicity fission, which leads to the hyperdeformed scission mode. Cluster radioactivity is discussed both as a heavy cluster emission process and as super-asymmetric fission. The theory as well as the present experimental status are reviewed. Physics at drip lines is interesting not only for their structural properties but also for their use in the fusion of two nuclei; both aspects are discussed.