Search results for "Isotopes of lithium"
showing 7 items of 17 documents
Identification of yrast high-Kintrinsic states inOs188
2009
The high-spin structure of the $Z=76$ nucleus $^{188}\mathrm{Os}$ has been studied using the incomplete fusion reaction $^{7}\mathrm{Li}+^{186}\mathrm{W}$. A ${K}^{\ensuremath{\pi}}={10}^{+}$ band has been established up to spin $({24}^{+})$ and its crossing with the ground-state band has been studied. In addition, intrinsic high-$K$ states have been identified and on top of two of them, ${K}^{\ensuremath{\pi}}={7}^{\ensuremath{-}}$ and ${K}^{\ensuremath{\pi}}={10}^{\ensuremath{-}}$, regular bands have been observed. The ${K}^{\ensuremath{\pi}}={16}^{+}$ and ${K}^{\ensuremath{\pi}}={18}^{+}$ states are yrast whereas the ${K}^{\ensuremath{\pi}}={14}^{+}$ level lies only 33 keV above the yras…
Charge radii and ground state structure of lithium isotopes: Experiment and theory reexamined
2011
Changes in the nuclear charge radii of lithium isotopes were determined using a combination of precise isotope shift measurements and theoretical atomic structure calculations. We discuss the choice of the reference isotope for absolute charge radii determinations in the lithium isotopic chain and report a new value for the charge radius of ${}^{6}$Li, based on the analysis of the world scattering data. A summary of the lithium nuclear charge radii obtained in this way is presented. Additionally, new calculations in fermionic molecular dynamics for the lithium isotopes were performed. We summarize the status of the lithium nuclear charge radii, magnetic dipole and electric quadrupole moment…
On total muon capture rates and the average neutrino energy
1973
A method of avoiding the uncertainty associated with the average neutrino energy nu in the usual closure approach to muon capture rates is discussed. Instead of neglecting the kinematic dependence on each particular channel, the partial capture rate is approximated by a first-order expansion around nu . After the sum over the final states is performed, the result is quite independent of the specific value of nu . Application to /sup 3/He, /sup 6/Li and closed-shell nuclei is given, as an effective test of the nuclear models used. (17 refs).
Experimental study of the halo nucleusHe6using theLi6(γ,π+)He6reaction
2007
The reaction $^{6}\mathrm{Li}$($\ensuremath{\gamma},{\ensuremath{\pi}}^{+})$$^{6}\mathrm{He}$ was studied over the angular range ${\ensuremath{\theta}}_{\ensuremath{\pi}}=40$--150$\ifmmode^\circ\else\textdegree\fi{}$ with the aim of investigating the halo structure of $^{6}\mathrm{He}$. Photons from a bremsstrahlung beam were tagged in the energy range ${E}_{\ensuremath{\gamma}}=170$--220 MeV at a resolution of $\ensuremath{\Delta}{E}_{\ensuremath{\gamma}}=630$ keV, and positively charged pions detected using high resolution stacked HpGe detectors. The measured angular distributions for the resolved $^{6}\mathrm{He}$ ground and 1.80 MeV excited states are compared to previous measurements a…
The quadrupole moment of the neutron-halo nucleus 11Li
1995
The quadrupole moment ratio of 9Li and 11Li was measured by a combination of in-beam laser induced nuclear polarization and β-NMR in LiNbO3. The result |Q(11Li)/Q(9Li)| = 1.14(16) is consistent with cluster models describing 11Li as composed of a 9Li core and a far extended halo of two loosely bound neutrons.
Absolute frequency measurements on the 2S→3S transition of lithium-6,7
2009
The frequencies of the 2S–3S two-photon transition for the stable lithium isotopes were measured by cavity-enhanced Doppler-free laser excitation that was controlled by a femtosecond frequency comb. The resulting values of 815 618 181.57(18) and 815 606 727.59(18) MHz, respectively, for 7Li and 6Li are in agreement with previous measurements but are more accurate by an order of magnitude. There is still a discrepancy of about 11.6 and 10.6 MHz from the latest theoretical values. This is comparable to the uncertainty in the theoretical calculations, while uncertainty in our experimental values is more than a hundred-fold smaller. More accurate theoretical calculation of the transition freque…
Stabilization of the rhombohedral phase in LiZr2(PO4)3 by thermal quenching
1993
Abstract Two LiZr2(PO4)3 samples, which show rhombohedral and monoclinic symmetries, have been studied by powder XRD and MAS-NMR (31P and 7Li) techniques. In the monoclinic sample phosphorus occupies three crystallographic sites and lithium is preferentially placed in M2 environment. When the samples are subjected to successive heating-quenching treatments, the rhombohedral phase is not appreciably modified while the monoclinic phase is transformed into the rhombohedral one. In the quenched samples only one site for phosphorus has been detected and occupancy of lithium in the more symmetric M1 site is favoured. After the thermal treatments, when the samples are stored at room temperature fo…