Search results for "CLEAR"
showing 10 items of 27042 documents
Nuclear mean-square charge radii of $^{63,64,66,68−82}$Ga nuclei: No anomalous behavior at N=32
2012
Collinear laser spectroscopy was performed on the 63,64,66,68−82Ga isotopes with neutron numbers from N = 32 to N = 51. These measurements were carried out at the ISOLDE radioactive ion beam facility at CERN. Here we present the nuclear mean-square charge radii extracted from the isotope shifts and, for the lighter isotopes, new spin and moment values. New ground-state nuclear spin and moments were extracted from the hyperfine spectra of 63,70Ga, measured on an atomic transition in the neutral atom. The ground-state spin of 63Ga is determined to be I = 3/2. Analysis of the trend in the change in mean-square charge radii of the gallium isotopes demonstrates that there is no evidence of anoma…
Prompt and delayed spectroscopy of 199At
2010
The neutron-deficient nucleus At199 has been studied through γ-ray and electron spectroscopy, using the recoil-decay tagging technique. Two experiments were conducted, using a gas-filled recoil separator with a focal-plane spectrometer alone and together with a germanium-detector array at the target position. The resulting level scheme for At199 includes a new isomer with a half-life of 0.80(5) μs and a spin and parity of (29/2+). The 13/2+ isomer, which de-excites via an M2 transition to the 9/2− ground state, was measured to have a half-life of 70(20) ns. Our earlier version of the level scheme for At197 has been updated as well. peerReviewed
Structure of 115Ag studied by β− decays of 115Pd and 115mPd
2012
The excited levels of 115Ag have been studied via the beta decay of 115Pd and 115Pdm. The beta-decay schemes for both states have been considerably extended, especially the scheme following the decay of 115Pdm which was practically unknown before this work. Transition intensities and log10 f t values are reported, which have been missing in the literature. A set of levels around 2 MeV has been found to be strongly populated by the beta decay of the ground state of 115Pd and is suggested to have a three-quasiparticle nature. The properties of excited levels have been compared with the level systematics of lighter neutron-rich silver isotopes, and new spin assignments as well as identificatio…
Candidate superdeformed band in 28Si
2012
Recent antisymmetrized molecular dynamics (AMD) calculations for 28Si suggest the presence of a superdeformed (SD) band with a dominant 24Mg + α clustering for its configuration, with firm predictions for its location and associated moment of inertia. This motivates a review of the experimental results reported in the literature with a particular focus on 24Mg(α,γ ) studies, as well as on α-like heavy-ion transfer reactions such as 12C(20Ne,α) 28Si. Combining this information for the first time leads to a set of candidate SD states whose properties point to their α-cluster structure and strong associated deformation. Analysis of data from Gammasphere allows the electromagnetic decay of thes…
First candidates for γ vibrational bands built on the [505]11/2⁻ neutron orbital in odd-A Dy isotopes
2020
Rotational structures have been measured using the Jurogam II and GAMMASPHERE arrays at low spin following the 155Gd(α,2n)157Dy and 148Nd(12C,5n)155Dy reactions at 25 and 65 MeV, respectively. We report high-K bands, which are conjectured to be the first candidates of a Kπ=2+γ vibrational band, built on the [505]11/2− neutron orbital, in both odd-A155,157Dy isotopes. The coupling of the first excited K=0+ states or the so-called β vibrational bands at 661 and 676 keV in 154Dy and 156Dy to the [505]11/2− orbital, to produce a Kπ=11/2− band, was not observed in both 155Dy and 157Dy, respectively. The implication of these findings on the interpretation of the first excited 0+ states in the cor…
Search for the terminating 27- state in 140Nd
2015
In the search for the fully aligned 27− state in 140Nd predicted by cranked Nilsson-Strutinsky calculations, new close-to-spherical high-spin states have been discovered. Both the close-to-spherical and the triaxial calculated states are in good agreement with the experimental results, supporting the existence of shape coexistence up to very high spins. Shell-model calculations using a newly developed effective interaction for the 50 N ,Z 82 mass region are in good agreement with the observed spherical states. The comparison between the experimental and calculated level energies allowed the relative energy to be established between several proton and neutron orbitals at high energy and spin…
Some Evidence of the Cluster Struture Inside of 9Be
2017
Angular distributions of protons, deuterons, tritons and alpha-particles emitted from the reactions in the 2H+9Be-system at Elab=19.5 MeV were measured with an aim to shed light on the internal cluster structure of 9Be and the study of possible cluster transfer of 5He. The analyses suggest a significant contribution of five-nucleon transfer in the reaction channel 9Be(d,4He)7Li. peerReviewed
Interweaving of elementary modes of excitation in superfluid nuclei through particle-vibration coupling: Quantitative account of the variety of nucle…
2015
A complete characterization of the structure of nuclei can be obtained by combining information arising from inelastic scattering, Coulomb excitation, and γ -decay, together with one- and two-particle transfer reactions. In this way it is possible to probe both the single-particle and collective components of the nuclear many-body wave function resulting from the coupling of these modes and, as a result, diagonalizing the low-energy Hamiltonian. We address the question of how accurately such a description can account for experimental observations in the case of superfluid nuclei. Our treatment goes beyond the traditional approach, in which these properties are calculated separately, and mos…
Decay spectroscopy of 179 82 Pb 97 and evidence for a 9/2− intruder state in 179 81 Tl 98
2017
The very neutron-deficient isobars 179Pb and 179Tl have been produced using the fusion-evaporation reactions 104Pd(78Kr,xpyn), where x≤1 and y≥2. The gas-filled separator RITU was employed to transport and separate the recoiling nuclei of interest from the scattered beam and unwanted products. The GREAT spectrometer was used to study the decay properties through α−α and α−γ correlations, which has allowed the ground state of 179Pb to be assigned as Iπ=9/2−. The decay of 179Pb was measured to have an α-particle energy and half-life of Eα=7348(5)keV and t1/2=2.7(2) ms, respectively. A search for a νi13/2 state in 179Pb was performed, but only a limit of excitation energy and half-life was obt…
'We have a solution': Delivering on the promise to take national responsibility for nuclear waste management
2022
We examine the realization of the umbrella promise to assume national responsibility for the final disposal of spent nuclear fuel. Three case studies are used to illustrate how Finland delivers on the promise to take care of its own nuclear waste - a promise that has greatly contributed to the legitimacy of nuclear power in Finland. The article shows how this promise is being challenged by new competitors, business visionaries, and the public. The case studies illustrate the tensions between those who made the promise and the actors who interpret and mobilize the promise for varying purposes and under changing circumstances. We investigate techno-scientific promises by looking at debates ab…