Search results for "Ground"
showing 10 items of 2432 documents
Investigations into the alpha-decay of 195At
2003
The low-energy nuclear structure and decay properties of the neutron-deficient isotopes 195At and 191Bi have been studied. 195At was produced in the reaction 142Nd(56Fe,p2n)195At and 191Bi as the daughter activity of 195At. The activities were implanted in a position-sensitive silicon detector after being separated from the primary beam by a gas-filled recoil separator. The 1/2+ intruder state was determined to be the ground state in 195At with an alpha-decay energy of E α = 6953(3) keV and a half-life T 1/2 = 328(20) ms. Another state with an alpha-decay energy E α = 7075(4) keV and a half-life T 1/2 = 147(5) ms was found to decay to a 148.7(5) keV excited state in 191Bi for which a spin a…
Observation of strongly deformed ground-state configurations in $^{184}$Au and $^{183}$Au by laser spectroscopy
1988
Resonance ionization mass spectroscopy (RIMS) and pulsed-laser induced desorption (PLID) have been combined in order to study the isotope shift (IS) and hyperfine structure (HFS) of184Au (T1/2=53 s) and183Au (T1/2=42 s) in the 6s2S1/2 → 6p2P1/2 (λ=267 nm) transition. The Au isotopes were obtained as daughters in the decay of184,183Hg produced and mass separated at the new ISOLDE-3 facility at CERN. It was found that the strong deformationβ2}-0.25 setting in at186Au persists down to183Au.
The deformedN=60 nucleus 41 101 Nb
1991
The β− decay of101Zr has been investigated at the fission-product separators JOSEF and LOHENGRIN. The half-life of101Zr has been determined to 2.5(1) s and a level scheme for101Nb has been established fromγ ray singles as well as X/3-γ and γ—γ coincidence measurements. Conversion coefficients for transitions in101Nb and level half-lives between 10 ps and 2 ns have been determined. Three rotational bands are identified among the low-lying levels with band heads at 0 keV, 206 keV and 208 keV. The bands are probably based on the Nilsson configurations [422 5/2+], [301 3/2−] and [303 5/2−], respectively. The deformation has been determined to βq=0.40(4) and 0.41(8) for the ground state band and…
High-resolution study of the beta decay of 41Ti
1997
Abstract An improved high-resolution study of the beta decay of 41 Ti, produced in the 40 Ca( 3 He, 2n) reaction at 40 MeV, has been performed at the Ion Guide Isotope Separator On-Line (IGISOL) facility. The beta-delayed radiation was detected by a low-energy charged-particle detector and a large Ge detector for gamma rays. The experimental beta-decay strength and its distribution, extracted from delayed-proton data, are compared with results of shell-model calculations in the sdfp space. The lowest J π = 3 2 + , T = 3 2 state in 41 Sc, the isobaric analogue state of the 41 Ti ground state, is estimated to contain 10% isospin impurity.
Lithium isotopes beyond the drip line
2008
The unbound isotopes 10Li, 12Li and 13Li have been observed after nucleon-knockout reactions at relativistic energies with 11Li and 14Be beams impinging on a liquid hydrogen target. The channels , and were analysed in the ALADIN-LAND setup at GSI. The 10Li data confirm earlier findings, while the 12Li and 13Li nuclei were observed for the first time. The relative-energy spectrum shows that the ground state of 12Li can be described as a virtual s-state with a scattering length of -13.7(1.6) fm. A broad energy spectrum was found for the channel. Based on the assumption that the relative-energy spectrum is dominated by a correlated background presumably stemming from initial correlations in th…
First applications of Fayans functional to deformed nuclei
2014
First calculations for deformed nuclei with the Fayans functional are carried out for the uranium and lead isotopic chains. The ground state deformations and deformation energies are compared to Skyrme-Hartree-Fock-Bogolyubov results of HFB-17 and HFB-27 functionals. For the uranium isotopic chain, the Fayans functional predictions are rather similar properties compared to HFB-17 and HFB-27. However, there is a disagreement for the lead isotopic chain. Both of the Skyrme HFB functionals predict rather strong deformations for the light Pb isotopes which does not agree with the experimental data on charge radii and magnetic moments of the odd Pb isotopes. On the other hand, the Fayans functio…
Ground-state properties of neutron-deficient platinum isotopes
1992
The hyperfine structure splitting and the isotope shift in the λ=266 nm transition of Pt isotopes within the mass range 183 ≦A≦ 198 have been determined by Resonance Ionization Mass Spectroscopy (RIMS) in combination with Pulsed-Laser Induced Desorption (PLID). The Pt isotopes were obtained at the on-line isotope separator ISOLDE-3/CERN as daugthers of the primarily produced Hg isotopes. Magnetic moments, quadrupole moments, and changes in the mean-square charge radii are deduced and compared with results of a particle-triaxial rotor model and mean field calculations. Good agreement with experimental data (including nuclear level schemes and transition probabilities) can only be obtained if…
Quadrupole moments and mean-square charge radii in the bismuth isotope chain
1997
Abstract Isotope shifts and hyperfine structures of the 205,206,208,210,210m,212,213 Bi isotopes have been studied on the 306.7 nm line using gas cell laser spectroscopy. The neutron-rich isotopes are the first isotones of Pb to be measured immediately above the N = 126 shell closure. The ground state quadrupole moments of the even- N isotopes increase as neutrons are added or removed from the N = 126 shell, but no corresponding increase is observed in the charge radii.
Ground state properties of manganese isotopes across the N=28 shell closure
2010
Abstract The first optical study of the N = 28 shell closure in manganese is reported. Mean-square charge radii and quadrupole moments, obtained for ground and isomeric states in 50–56 Mn, are extracted using new calculations of atomic factors. The charge radii show a well defined shell closure at the magic number. The behaviour of the charge radii is strikingly different to that of the neutron separation energies where no shell effect can be observed. The nuclear parameters can be successfully described by large scale shell model calculations using the GXPF1A interaction.
Deformation of Sr and Rb isotopes close to theN=Zline viaβ-decay studies using the total absorption technique
2013
A study of the Gamow-Teller strength distributions $B$(GT) in the beta decay of ${}^{78}$Sr and ${}^{76,78}$Rb has been made using a total absorption spectrometer (TAS). Following the success in deducing the sign of the deformation for ${}^{76}$Sr, a similar approach is adopted for ${}^{78}$Sr based on a comparison of the measured $B$(GT) with quasiparticle random-phase approximation calculations. This work confirms its previously expected prolate deformation in the ground state. Conclusions about the structure of the odd-odd ${}^{76,78}$Rb isotopes have been drawn based on their measured $B$(GT) distributions.