[en] The Clark University research program in nuclear structure is a collaborative effort involving Clark University personnel, staff members from Brookhaven National Laboratory and an active participation of scientists from the US and other nations. The TRISTAN on-line isotope separator and the capture γ-ray facility at the High Flux Beam Reactor have been the primary experimental foci of the program although experiments have been carried out at other installations such as the High Flux Reactor of the Institute Laue-Langevin in Grenoble and at the Tandem Van de Graaff Accelerator, Yale University. Recently, we have joined colleagues from Argonne National Laboratory, Vanderbilt University and the University of Maryland in experiments using the Fragment Mass Analyzer (FMA) at the ATLAS accelerator. Our program has four principal research themes which underlie the various research initiatives, three involving nuclear structure physics and one directed towards astrophysics. These themes are: (1) the critical role of the proton-neutron interaction in the evolution of nuclear structure and its relation to collectivity, (2) the study of exotic nuclei far-from-stability produced by radioactive ion beams (REBs), (3) the appearance and role of dynamical symmetries in nuclei and the characterization of transitions among these limits, and (4) the characterization and prediction of properties of nuclei far from stability of importance in stellar nucleosynthesis

[en] The Clark University research program in nuclear structure is a collaborative effort involving Clark University personnel, staff members from Brookhaven National Laboratory and from Ames Laboratory (Iowa State University), and an active participation of foreign scientists. The TRISTAN on-line isotope separator and the capture γ-ray facility at the HFBR are the experimental foci of the program which has four principal research themes, three involving nuclear structure physics and one directed towards astrophysics. These themes are: the manifestation of the proton-neutron interaction in the evolution of nuclear structure and its relation to collectivity, the appearance and the role of symmetries and supersymmetries in nuclei, the study of new regions of magic nuclei, and the characterization of nuclei important in r-process stellar nucleosynthesis. The activities involving Clark personnel during the eight month period, February 1, 1988 -- September 30, 1988, are summarized below

[en] This research program is concerned with measuring atomic masses and decay schemes of short-lived, neutron-rich fission products with the TRISTAN on-line mass separator located at the High Flux Beam Reactor (HFBR), Brookhaven National Laboratory. The determination of accurate masses for neutron-rich nuclei is useful in refining mass equations wich, in turn, are important for calculations related to astrophysical processes and to control and safety of nuclear reactors. During the period covered by this report, efforts have been to aid Brookhaven personnel in the installation and testing of TRISTAN and the associated computer systems, and to begin a program of measurements of β-ray end-point energies and nuclear decay schemes following successful demonstration of the facility. 2 figures

[en] The techniques for measuring fission product masses far from stability are discussed and recent progress in experimental measurements is reviewed. A comparison of new mass values with predictions of 10 mass equations suggests that most theories predict far-from-stability fission product nuclei to be more bound than is found experimentally. A closer look at several isotopic chains is used to identify regions of structural change where mass equations encounter difficulty. 31 references

No abstract available

[en] The Clark University research program in nuclear structure is a collaborative effort involving Clark University personnel, staff members from Brookhaven National Laboratory and an active participation of scientists from other nations. The TRISTAN on-line isotope separator and the capture γ-ray facility at the HFBR are the experimental foci of the program which has four principal research themes, three involving nuclear structure physics and one directed towards astrophysics. These themes are: (1) the manifestation of the proton-neutron interaction in the evolution of nuclear structure and its relation to collectivity, (2) the appearance and the role of symmetries and supersymmetries in nuclei, (3) the study of new regions of magic nuclei, and (4) the characterization of nuclei important in r-process stellar nucleosynthesis. The activities involving Clark personnel during the operating period of Grant No. FG02-88ER40417, August 1, 1991--July 31, 1992, are summarized

[en] The research program is concerned with measuring atomic masses and decay schemes of short-lived, neutron-rich fission products using the TRISTAN on-line mass separator located at the High Flux Beam Reactor (HFBR), Brookhaven National Laboratory. The determination of accurate masses for neutron-rich nuclei is useful in testing and refining mass equations which, in turn, find important application in calculations of astrophysical processes and for control and safety of nuclear reactors. The thrust of the spectroscopic studies has been to develop a data base for neutron-rich, far-from-stability nuclides in order to provide a new testing ground for nuclear models. In particular, we have been active in pursuing microscopic and phenomenological understanding of nuclear structure in regions of shape transition near shell and subshell closures

[en] The Clark University research program is concerned with the measurement of atomic masses and understanding the nuclear structures of isotopes far from the line of β stability. This work is accomplished, primarily, by use of the TRISTAN on-line mass separator located at the High Flux Beam Reactor, Brookhaven National Laboratory, where investigations of short-lived fission products have been actively pursued for the past four years. In 1985 mass measurements of light isotopes produced by fragmentation reactions on heavy targets will begin using the TOFI (Time-of-Flight Isochronous) Spectrometer at the LAMPF accelerator, Los Alamos National Laboratory. Together, the two facilities are capable of providing complementary information, potentially of great value in understanding the sum total effect of all nuclear interactions in a given nucleus, which gives rise to the property known as the mass. The thrust of the spectroscopic studies at TRISTAN has been to develop a data base for neutron-rich, far-from-stability nuclides in order to provide a new testing ground for nuclear models. In particular, we have been active in pursuing microscopic and phenomenological understanding of nuclear structure in regions of shape transition near shell and subshell closures. Recent efforts have been concentrated on investigating the interplay of vibrational and rotation-like intruder state degrees of freedom as manifested, for example, in even Cd isotopes near the Z=50 shell. Such studies provide crucial tests of nuclear wave functions and model Hamiltonians

[en] The Clark University research program is concerned with experimental determination of the nuclear structure of isotopes far from the line of β stability and their masses. This work is accomplished, primarily, by use of the TRISTAN on-line mass separator located at the High Flux Beam Reactor, Brookhaven National Laboratory, where investigations of short-lived fission products have been actively pursued since 1980. In 1985 mass measurements of light isotopes produced by fragmentation reactions on heavy targets were initiated using the TOFI (Time-of-flight Isochronous) Spectrometer at the LAMPF accelerator, Los Alamos National Laboratory. Together, the two facilities are capable of providing complementary information, potentially of great value in understanding the sum total effect of all nuclear interactions in a given nucleus, which gives rise to the property known as the mass. The thrust of the spectroscopic studies at TRISTAN has been to develop a database for neutron-rich, far-from-stability nuclides in order to provide a new testing ground for nuclear models. In particular, we have been active in pursuing microscopic and phenomenological understanding of nuclear structure in regions of shape transition near shell and subshell closures. Recent efforts have been concentrated on exploiting some very new ideas based on the pervasive influence of the proton-neutron interaction that offer the possibility of achieving a unified interpretation of nuclear structure and its evolution, of the interrelationships of different nuclear shapes and modes of excitation, and of the nuclear mass

[en] The Clark University research program in nuclear structure is a collaborative effort involving Clark University personnel, staff members from Brookhaven National Laboratory and an active participation of scientists from the US and other nations. The TRISTAN on-line isotope separator and the capture γ-ray facility at the High Flux Beam Reactor are the primary experimental foci of the program which has four principal research themes, three involving nuclear structure physics and one directed towards astrophysics. These themes are: (1) the manifestation of the proton-neutron interaction in the evolution of nuclear structure and its relation to collectivity, (2) the appearance and the role of symmetries and supersymmetries in nuclei, (3) the study of new regions of magic nuclei, and (4) the characterization of nuclei important in r-process stellar nucleosynthesis