No abstract available

[en] A summary is given of work completed and continued during 1975 in the areas of neutron and fission physics, charged-particle reactions, and theory

[en] A generalization of the relativistic eikonal amplitude originally developed to describe elastic scattering between structured particles is introduced. The coherent and incoherent proton-nucleus scattering processes are analysed and closed forms expressions for elastic and inelastic amplitudes are derived. In particular, for incoherent case, an energy conserving version of Glauber's theory is obtained. (author)

[en] National Nuclear Data Center (NNDC) maintains a number of data bases containing bibliographic information and evaluated as well as experimental nuclear properties. An evaluated computer file maintained by the NNDC, called the Evaluated Nuclear Structure Data File (ENSDF), contains nuclear structure information for all known nuclides. The ENSDF is the source for the journal ''Nuclear Data Sheets'' which is produced and edited by NNDC. The Evaluated Nuclear Data File (ENDF), on the other hand is designed for storage and retrieval of such evaluated nuclear data as are used in neutronic, photonic, and decay heat calculations in a large variety of applications. Some of the publications from these data bases are the Nuclear Wallet Cards, Radioactivity Handbook, and books on neutron cross sections and resonance parameters. In addition, the NNDC maintains three bibliographic files: NSR - for nuclear structure and decay data related references, CINDA - a bibliographic file for neutron induced reactions, and CPBIB - for charged particle reactions. Selected retrievals from evaluated data and bibliographic files are possible on-line or on request from NNDC. 6 refs., 1 fig

[en] Kinetics for the nucleophiles have been studied under high vacuum and high pressures in various temperatures. Pseudo-first order rate constants, second order rate constants, thermodynamic parameters and Hammett ρ-values are determined. The values of ΔV†, Δβ† and ΔS† are all negative. The Hammett ρ-values are negative for the nucleophile (ρ_X) over the pressure range studied. The results of kinetic studies for pressure and nucleophilet show that these reactions proceed in typical S_N2 reaction mechanism and change of mechanism

[en] Version VI of the Evaluated Nuclear Data File (ENDF/B-VI) was released in 1990. For ENDF/B-VI major emphasis was placed on standards, isotopic evaluations, energy balance, improved resonance region representations, and improvement of neutronics files for important actinides. Data testing proceeds at a pace much slower than previous versions but more results are now being accumulated. Two versions have been released to data and a third is planned after the next meeting of the Cross Section Evaluation Working Group (CSEWG), currently planned for October 1994

[en] The transition from the resonance reaction mechanism at low level density to the direct reaction mechanism at high level density is investigated by means of numerical results obtained from microscopic calculations for nucleon-induced reactions. The transition takes place rather sharply at Γ ≅ D-bar. Here, two types of motion of the nucleons exist simultaneously: a motion in long-living states which are near equilibrium and a motion in short-living states which are far from equilibrium. A formation of order out of chaos takes place only in the open quantum mechanical nuclear system. It is caused by quantum fluctuations via the continuum. (author)

[en] We study multiple preequilibrium emission in nucleon induced reactions at intermediate energies, and compare quantum molecular dynamics (QMD) calculations with multistep-direct Feshbach-Kerman-Koonin results [M. B. Chadwick, P. G. Young, D. C. George, and Y. Watanabe, Phys. Rev. C 50, 996 (1994)]. When the theoretical expressions of this reference are reformulated so that the definitions of primary and multiple emission correspond to those used in QMD, the two theories yield similar results for primary and multiple preequilibrium emission. We use QMD as a tool to determine the multiplicities of fast preequilibrium nucleons as a function of incident energy. For fast particle cross sections to exceed 5% of the inclusive preequilibrium emission cross sections we find that two particles should be included in reactions above 50 MeV, three above about 180 MeV, and four are only needed when the incident energy exceeds about 400 MeV

[en] The structure of the neutron-rich isotopes ⁷He, ¹⁰Li and ¹¹Be has been studied in detail using multi-nucleon transfer reactions. New results have been obtained for ⁷He, where there is evidence for the observation of the first excited state,, i.e. the 1/2^- -resonance, which is of interest for the spin-orbit splitting in these light neutron-rich nuclei. Reactions of distinct selectivity have been chosen to study the states of ¹⁰Li, which are all unbound. The structure of the eight states found in these reactions is discussed, and the relevance for the decay of ¹¹Li resonances is shown. The isotopes ¹⁰Be and ¹¹Be have been investigated to study the α-cluster structure and high-lying states. Nine states of the observed ¹¹Be-resonances form a molecular rotational band. The multi-nucleon transfer mechanism has also been applied to study the unbound proton-rich isotope ¹¹N, the mirror nucleus of ¹¹Be. In this case the ¹²C(¹⁴N,¹⁵C)¹¹ N-reaction has been used. Five resonances have been observed, and the lowest two can be identified as 1/2^- -and 5/2⁺ -states

[en] Several fields of practical importance are existing for neutron induced charged particle reactions despite their low position within the cross section hierarchy. A survey is given on the experimental techniques employed to obtain information on cross sections, energy and angular distribution for this class of reactions. The obtainable accuracies are discussed and compared with the accuracies requested for the practical applications. The main areas of work, presently neglected, requiring future attention can be identified: (1) Reactions on medium mass nuclei not accessible by the activation method and (2) The neutron energy region between 6 and 12 MeV where suited neutron sources are not easily available. 2 tables, 4 figures