Engineering topics
Casten, R F
Publications and source records attributed to Casten, R F.
Cadmium mass measurements between the neutron shell closures at N = 50 and 82
The mass values of the neutron-deficient cadmium isotopes {sup 99-109}Cd and of the neutron-rich isotopes {sup 114,120,122-124,126,128}Cd have been measured using ISOLTRAP. The behavior of the separation energies of the cadmium isotopes from N = 50 to 82 is discussed.
Mass measurements on stable nuclides in the rare-earth region with the Penning-trap mass spectrometer TRIGA-TRAP
The masses of 15 stable nuclides in the rare-earth region have been measured with the Penning-trap mass spectrometer TRIGA-TRAP. This is the first series of absolute mass measurements linking these nuclides to the atomic-mass standard {sup 12}C. Previously, nuclear reaction studies almost exclusively determined the literature values of these masses in the Atomic-Mass Evaluation. The TRIGA-TRAP results show deviations on the order of 3-4 standard deviations from the latest published values of the Atomic-Mass Evaluation 2003 for some cases. However, the binding-energy differences that are important for nuclear structure studies have been confirmed and improved. The new masses are discussed in the context of valence proton-neutron interactions using double differences of binding energies, {delta}V{sub pn}(Z,N).
Studying the Atomic Nucleus - A New Era in Nuclear Structure Studies
The study of atomic nuclei is part of the fascinating quest to understand the fundamental nature and origins of matter. This field, nuclear structure, is undergoing a revolutionary transformation that is breaking cherished paradigms, opening new vistas of nuclear matter for study, and which has the promise of leading to a new comprehensive understanding. The advent of new facilities for the production and study of exotic nuclei provides access to an entirely new territory of nuclei, and advances in extreme computing are enabling similar advances in the theory of atomic nuclei.
Low-energy structure of the even- A Ru 96 − 104 isotopes via g -factor measurements
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Indication of a mini-valence Wigner-like energy in heavy nuclei
Certain double differences of binding energies can be constructed that exhibit the valence proton-neutron interaction. These double differences, known as {delta}V{sub pn}(Z,N), show singularities in light N=Z even-even nuclei (and N=Z-1 even-Z, odd-N nuclei) due to uniquely large overlaps of the proton and neutron wave functions and the short-range residual interaction. It is suggested that a similar phenomenon appears, heavily muted, in heavy nuclei as well, when one considers valence nucleon numbers. It is proposed that it arises from the overall similarity of the sequences of orbits in different major shells, giving higher overlaps when the respective proton and neutron shells are approximately equally filled.
Correlations of experimental isotope shifts with spectroscopic and mass observables
Experimental differential observables relating to mean square charge radii, spectroscopic, and mass observables of even-even nuclei are presented for different regions in the nuclear chart. They exhibit remarkable correlations, not heretofore recognized, that provide a new perspective on structural evolution, especially in exotic nuclei. This can also be a guide for future measurements of charge radii, spectroscopic observables, and masses, as well as for future theoretical approaches.
Investigation of 0{sup +} states in {sup 192}Pt and {sup 194}Pt isotopes
Excited states in {sup 192}Pt and {sup 194}Pt have been studied with high-energy resolution, in the (p,t) reaction, by using the Q3D magnetic spectrograph at the Munich MP tandem accelerator. Outgoing tritons were recorded at laboratory angles sensitive to the unique shape of the L=0 angular distribution. Sets of previously unknown 0{sup +} states were identified up to an energy of {approx}3 MeV. The 0{sup +} states in {sup 192,194}Pt are discussed in the context of the evolution of intruder states and shape coexistence in the light Pt isotopes.
Masses and Structure
The use of nuclear masses to elucidate structure and its evolution with Z and N is discussed, with emphasis on two-neutron separation energies and the proton-neutron interaction as extracted from double differences of binding energies. The enhanced sensitivity of masses to structure in deformed nuclei is also discussed.