Search results for "Spins"
showing 10 items of 257 documents
Very high rotational frequencies and band termination in73Br
2000
Rotational bands in ${}^{73}\mathrm{Br}$ have been investigated up to spins of $I=65/2$ using the EUROBALL III spectrometer. One of the negative-parity bands displays the highest rotational frequency $\ensuremath{\Elzxh}\ensuremath{\omega}=1.85\mathrm{MeV}$ reported to date in nuclei with $Ag~25.$ At high frequencies, the experimental ${\mathcal{J}}^{(2)}$ dynamic moment of inertia for all bands decreases to very low values, ${\mathcal{J}}^{(2)}l~10{\ensuremath{\Elzxh}}^{2}{\mathrm{MeV}}^{\ensuremath{-}1}.$ The bands are described in the configuration-dependent cranked Nilsson--Strutinsky model. The calculations indicate that one of the negative-parity bands is observed up to its terminatin…
Experimental evidence for chirality in the odd-A 105Rh
2004
Abstract High-spin states in 105 Rh were populated by the 96 Zr( 13 C, p3n) reaction at beam energies of 51 and 58 MeV, and studied using the EUROBALL IV γ -ray spectrometer and the DIAMANT charged particle array. A pair of nearly degenerate Δ I = 1 three-quasiparticle bands with the same spins and parity have been observed. Comparison of the experimental results with tilted axis cranking calculations confirms the chiral character of the two bands, while arguments based on the excitation of particles within the π g 9 / 2 ν ( h 11 / 2 ) 2 configuration of the yrast band and comparison with the previously observed γ band exclude the other possible interpretations. This is the first experiment…
Spectroscopy of the neutron-deficientN=50nucleusRh95
2014
The neutron-deficient semimagic (neutron number N = 50) Rh-95 nucleus has been produced at high spins using the projectile-target system Ca-40 + Ni-58 at 125 MeV beam energy. The gamma-decays of le ...
Nuclear moments, charge radii and spins of the ground and isomeric states in175Yb and177Yb
2012
This paper reports static moments and changes in mean-square charge radii of 175, 177, 177mYb measured using collinear laser spectroscopy at the IGISOL facility. The moments are compared to predictions made using the Nilsson model to determine the purity of the multi-quasiparticle T1/2 = 11.4 s, Iπ = 8− state of 176Yb and the ground state of 177Yb. The ground-state spins of 175, 177Yb and the T1/2 = 6.41 s, E = 331.5 keV isomeric state in 177Yb, have been measured from the hyperfine structure to be 7/2, 9/2 and 1/2 respectively.
Limit on Lorentz andCPTviolation of the bound neutron using a free precessionHe3/Xe129comagnetometer
2010
We report on the search for Lorentz-violating sidereal variations of the frequency difference of colocated spin species while the Earth and hence the laboratory reference frame rotates with respect to a relic background field. The comagnetometer used is based on the detection of freely precessing nuclear spins from polarized 3 He and 129 Xe gas samples using SQUIDs as low-noise magnetic flux detectors. As result we can determine the limit for the equatorial component of the background field interacting with the spin of the bound neutron to be b n ⊥ < 3.7 · 10- 32 GeV (95% C.L.).
Low-spin structure of85Se and theβnbranching of85As
2012
Fission fragments from neutron-induced fission of ${}^{235}$U produced at the high-flux reactor of the Institut Laue-Langevin, Grenoble, were separated with the Lohengrin separator to provide a beam of neutron-rich ${}^{85}\phantom{\rule{-0.16em}{0ex}}$As nuclei. The ${\ensuremath{\beta}}^{\ensuremath{-}}$ decay of ${}^{85}\phantom{\rule{-0.16em}{0ex}}$As to ${}^{85}$Se was studied using $\ensuremath{\gamma}$-$\ensuremath{\gamma}$ and $\ensuremath{\beta}$-$\ensuremath{\gamma}$ coincidence techniques. ${}^{85}$Se was also studied using the prompt-$\ensuremath{\gamma}$ coincidence data from spontaneous fission of ${}^{248}$Cm and ${}^{252}$Cf measured with the Eurogam2 and Gammasphere Ge arra…
Model independent determination of the spin of theTa180naturally occurring isomer
2006
The hyperfine structures of the 33715.27 ${\mathrm{cm}}^{\ensuremath{-}1}$ and 33706.47 ${\mathrm{cm}}^{\ensuremath{-}1}$ transitions from the ground state of singly ionized Ta have been measured by collinear laser spectroscopy. The structures were found to contain a large second order contribution. From fitting the observed hyperfine components for both $^{181}\mathrm{Ta}$ and the $^{180}\mathrm{Ta}$ naturally occurring isomer it was possible to determine the first and second order hyperfine structure coefficients. As no model independent determination of the nuclear spin of the $^{180}\mathrm{Ta}$ isomer has been performed, fitting was attempted for a range of spins. A clear chi-squared m…
Nuclear ground state spins of short-lived strontium isotopes
1987
Nuclear ground state spins of the odd-mass strontium isotopes between A=79 and 97 were determined by measurements of the hyperfine structure in the ionic transition 5s2S1/2−5p2P3/2. The spins of93Sr and97Sr are revised to I=5/2 and I=1/2, respectively, while assignments for the remaining isotopes are confirmed.
Nuclear moments and charge radii of neutron-deficient francium isotopes and isomers
2015
Collinear laser fluorescence spectroscopy has been performed on the ground and isomeric states of $^{204,206}\mathrm{Fr}$ in order to determine their spins, nuclear moments, and changes in mean-squared charge radii. A new experimental technique has been developed as part of this work which much enhances the data collection rate while maintaining the high resolution. This has permitted the extension of this study to the two isomeric states in each nucleus. The investigation of nuclear $g$ factors and mean-squared charge radii indicates that the neutron-deficient Fr isotopes lie in a transitional region from spherical towards more collective structures.
Nuclear spins, moments and charge radii of108?111Sn
1987
The hyperfine structure splittings (hfs) and isotope shifts (IS) in the atomic transitions 5s2 5p21S0 → 5s2 5p6s1,3P1 have been measured for the radioactive isotopes108−111Sn and all stable ones. The tin isotopes were prepared as fast atomic beams for collinear laser spectroscopy at the GSI online mass separator following a fusion reaction. Nuclear spins, magnetic dipole, electric quadrupole moments and changes in mean square charge radii have been determined. In109Sn the spinI=5/2 was measured for the nuclear ground state (T1/2=18 min) in contradiction to the literature value. The mean square charge radii show a parabolic behaviour with a maximum at N=66. This is interpreted by collective …