A consistent description of the nuclear α-decay process
The essential features of a new theory of α decay and the need for such a theory are reviewed. An approximate relationship between half life and α-particle energy is deduced and checked for the decay of even polonium isotopes. Detailed calculations of one-body widths and spectroscopic factors for the polonium decays are presented and the implications of the results are discussed. It is also shown that the result for the α decay of 212Po is consistent with the reverse α-transfer reaction.
Clusters as subsystems in light nuclei . Direct cluster reactions : progress towards a unified theory
This article is intended to give a very simple and straightforward discussion of what we mean when we talk about “clusters” in the context of direct reactions and scattering. Although three very informative international conferences have been held up to now there remains a good deal of uncertainty about the significance of clustering in nuclei and some conflict and confusion over the techniques necessary to describe the reactions which are designed to probe this effect. It is likely that this article will pose more questions than it succeeds in answering because the principle objective will be to clarify the problems and understand more clearly why difficulties and disagreements have arisen. No attempt has been made to give a complete review of theoretical work or of experimental data; instead references have been chosen to illustrate the key points.
Impact of Nuclear Data Uncertainties on Transmutation of Actinides in Accelerator-Driven Assemblies
Abstract The potential impact of nuclear data uncertainties on a large number of performance parameters of reactor cores dedicated to the transmutation of radioactive wastes is discussed. An uncertainty analysis has been performed based on sensitivity theory, which underlines the cross sections, the energy range, and the isotopes that are responsible for the most significant uncertainties. To provide guidelines on priorities for new evaluations or validation experiments, required accuracies on specific nuclear data have been derived, accounting for target accuracies on major design parameters. The required accuracies (mostly in the energy region below 20 MeV), in particular for minor actinide data, are of the same order of magnitude of the achieved accuracies on major actinides. Specific requirements also concern the improvement of minor actinide data related to decay heat and effective delayed-neutron fraction assessment.