Engineering topics
Publications and source records attributed to Cakirli, R B.
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.
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).
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.
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.
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.
Ion traps are known as ideal tools for precision measurements of fundamental particle properties. In particular, traps have been set up at Radioactive Ion Beam (RIB) facilities to investigate exotic nuclei. During the last decade this field of research has constantly grown, with currently almost a dozen ion-trap systems at RIB facilities in Europe and North America and several more planned at future accelerators projects. One of these, the Advanced Trapping System MATS will be installed at the low-energy branch for radioactive-ion beams at the Facility for Antiprotons and Ion Research (FAIR) in Darmstadt (Germany). One of the MATS features will be non-destructive ion detection based on Fourier-Transform Ion-Cyclotron-Resonance Mass Spectrometry (FT-ICR MS). A prototype of the system has been developed at the Max-Planck-Institute for Nuclear Physics in Heidelberg (Germany) and recent results are outlined in this contribution.