New measurement and reevaluation of the nuclear magnetic andquadrupole moments ofLi8andLi9<

Abstract

The nuclear magnetic moment of 9 Li and the quadrupole moments of 8 Li and 9 Li have been measured by use of the β-asymmetry detection of nuclear magnetic resonance on optically polarized beams at ISOLDE/CERN. The radioactive beams were implanted in Si for g-factor measurements and in Zn, LiNbO 3 , and LiTaO 3 crystals for quadrupole moment measurements. The electric-field gradient V zz = 4.26(4) × 10 15 V/cm 2 is deduced for Li in Zn. Using a recently adopted reference value, Q( 7 Li) = −40.0(3) mb, we reevaluated all earlier reported nuclear quadrupole moments of 8 Li and 9 Li. Based on all available previous and present data, the adopted quadrupole moments for these isotopes are Q( 8 Li) = +31.4(2) mb and Q( 9 Li) = −30.6(2) mb. The magnetic moment of 9 Li is deduced as µ( 9 Li) = 3.43678(6)µ N . The values are compared with predictions from shell-model and cluster-model calculations.

Collinear laser spectroscopy at ISOLDE: new methods and highlights

“…is an order of magnitude more accurate than the previous value [21], due to the narrow resonance linewidth in the Si crystal as compared to Au or LiF hosts [24].…”

“…Based on these achievements a new effort was made after 2000 towards a considerable improvement of the quadrupole moment measurement on 11 Li, with the primary goal of detecting an influence of the halo neutrons on the 9 Li core which is responsible for the electrical properties. Compared to the previous approach, a new NMR magnet offered a more homogeneous magnetic field and from a systematic study of implantation crystals it became possible to gain an order of magnitude in resolution by replacing the LiNbO 3 ionic crystal by a metallic Zn crystal [24]. The multiple-rf resonance technique employed already previously, uses a set of radio frequencies depending on the quadrupole moment Q as a parameter and requires the exact knowledge of the Larmor frequency which is determined by the magnetic moment.…”

High-precision quadrupole moment reveals significant intruder component inAl201333ground state

“…, 5/2). When the applied rf field has a frequency that matches one of these frequencies, the population of the two magnetic substates is equalized, which induces only a partial destruction of the ensemble polarization, reflected as a small change in the asymmetry A [24]. In order to enhance this change in asymmetry and thus the resonance signal, the polarization needs to be fully destroyed.…”

The ab initio No-Core Shell Model and Light Nuclei

“…Still, the decrease of the charge radius of A = 6 − 9 isotopes is reproduced. Final results for all isotopes are presented in Table 2 together with recent and very precise experimental results using the nuclear magnetic resonance technique [19,15].…”

“…[16][17][18] for energies, Refs. [15][16][17]19] for electromagnetic moments, and from Refs. [20,21] for radii By diagonalizing the Hamiltonian (H − E) (A) = 0 in the space spanned by our basis functions we obtain a non-local, integro-differential coupled-channels Schrödinger Equation for the relative motion of the clusters in our different channels.…”