Precision Measurement of 11Li moments: Influence of Halo Neutrons on the 9Li Core

The electric quadrupole moment and the magnetic moment of the 11Li halo nucleus have been measured with more than an order of magnitude higher precision than before, |Q| = 33.3(5)mb and mu=3.6712(3)mu_N, revealing a 8.8(1.5)% increase of the quadrupole moment relative to that of 9Li. This result is compared to various models that aim at describing the halo properties. In the shell model an increased quadrupole moment points to a significant occupation of the 1d orbits, whereas in a simple halo picture this can be explained by relating the quadrupole moments of the proton distribution to the charge radii. Advanced models so far fail to reproduce simultaneously the trends observed in the radii and quadrupole moments of the lithium isotopes.Comment: 4 pages, 4 figures, 1 tabl

Optical polarization of neutron-rich sodium isotopes and β\beta-NMR measurements of quadrupole moments

The nuclear quadrupole moments of neutron-rich sodium isotopes are being investigated with the help of in-beam polarization by optical pumping in combination with $\beta$-NMR techniques. First measurements have yielded the quadrupole splittings of NMR signals in the lattice of LiNbO$_{3}$ for the isotopes $^{26}$Na, $^{27}$Na and $^{28}$Na. Interaction constants and ratios of the electric quadrupole moments are derived. In view of future experiments, $\beta$-decay asymmetries for the sequence of isotopes up to the $N$=20 neutron shell closure, $^{26-31}$Na, have been measured

Spins, Electromagnetic Moments, and Isomers of 107-129Cd

The neutron-rich isotopes of cadmium up to the N=82 shell closure have been investigated by high-resolution laser spectroscopy. Deep-UV excitation at 214.5 nm and radioactive-beam bunching provided the required experimental sensitivity. Long-lived isomers are observed in 127Cd and 129Cd for the first time. One essential feature of the spherical shell model is unambiguously confirmed by a linear increase of the 11/2- quadrupole moments. Remarkably, this mechanism is found to act well beyond the h11/2 shell

Quadrupole moments and mean-square charge radii in the bismuth isotope chain

Isotope shifts and hyperfine structures of the $^{205, 206, 208, 210, 210m, 212, 213}$Bi isotopes have been studied on the 306.7nm 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

Measurement of the magnetic moment of the one-neutron halo nucleus 11^{11}Be

The magnetic moment of $^{11}$Be was measured by detecting nuclear magnetic resonance signals in a beryllium crystal lattice. The experimental technique applied to a $^{11}$Be$^+$ ion beam from a laser ion source includes in-beam optical polarization, implantation into a metallic single crystal and observation of rf resonances in the asymmetric angular distribution of the $\beta$-decay ($\beta$-NMR). The nuclear magnetic moment $\mu(^{11}{\rm Be}) = -1.6816(8)\,\mu_N$ provides a stringent test for theoretical models describing the structure of the 1/2$^+$ neutron halo state

Monitoring Ion Channel Function In Real Time Through Quantum Decoherence

In drug discovery research there is a clear and urgent need for non-invasive detection of cell membrane ion channel operation with wide-field capability. Existing techniques are generally invasive, require specialized nano structures, or are only applicable to certain ion channel species. We show that quantum nanotechnology has enormous potential to provide a novel solution to this problem. The nitrogen-vacancy (NV) centre in nano-diamond is currently of great interest as a novel single atom quantum probe for nanoscale processes. However, until now, beyond the use of diamond nanocrystals as fluorescence markers, nothing was known about the quantum behaviour of a NV probe in the complex room temperature extra-cellular environment. For the first time we explore in detail the quantum dynamics of a NV probe in proximity to the ion channel, lipid bilayer and surrounding aqueous environment. Our theoretical results indicate that real-time detection of ion channel operation at millisecond resolution is possible by directly monitoring the quantum decoherence of the NV probe. With the potential to scan and scale-up to an array-based system this conclusion may have wide ranging implications for nanoscale biology and drug discovery.Comment: 7 pages, 6 figure

Calibration of the ISOLDE acceleration voltage using a high-precision voltage divider and applying collinear fast beam laser spectroscopy

A high-voltage divider with accuracy at the ppm level and collinear laser spectroscopy were used to calibrate the highvoltage installation at the radioactive ion beam facility ISOLDE at CERN. The accurate knowledge of this voltage is particularly important for collinear laser spectroscopy measurements. Beam velocity measurements using frequencycomb based collinear laser spectroscopy agree with the new calibration. Applying this, one obtains consistent results for isotope shifts of stable magnesium isotopes measured using collinear spectroscopy and laser spectroscopy on laser-cooled ions in a trap. The long-term stability and the transient behavior during recovery from a voltage dropout were investigated for the different power supplies currently applied at ISOLDE.Comment: 13 pages, 6 figure

Isomer shift and magnetic moment of the long-lived 1/2+^{+} isomer in 3079^{79}_{30}Zn49_{49}: signature of shape coexistence near 78^{78}Ni

Collinear laser spectroscopy has been performed on the $^{79}_{30}$Zn$_{49}$ isotope at ISOLDE-CERN. The existence of a long-lived isomer with a few hundred milliseconds half-life was confirmed, and the nuclear spins and moments of the ground and isomeric states in $^{79}$Zn as well as the isomer shift were measured. From the observed hyperfine structures, spins $I = 9/2$ and $I = 1/2$ are firmly assigned to the ground and isomeric states. The magnetic moment $\mu$ ($^{79}$Zn) = $-$1.1866(10) $\mu_{\rm{N}}$, confirms the spin-parity $9/2^{+}$ with a $\nu g_{9/2}^{-1}$ shell-model configuration, in excellent agreement with the prediction from large scale shell-model theories. The magnetic moment $\mu$ ($^{79m}$Zn) = $-$1.0180(12) $\mu_{\rm{N}}$ supports a positive parity for the isomer, with a wave function dominated by a 2h-1p neutron excitation across the $N = 50$ shell gap. The large isomer shift reveals an increase of the intruder isomer mean square charge radius with respect to that of the ground state: $\delta \langle r^{2}_{c}\rangle^{79,79m}$ = +0.204(6) fm$^{2}$, providing first evidence of shape coexistence.Comment: 5 pages, 4 figures, 1 table, Accepeted by Phys. Rev. Lett. (2016

TRIGA-SPEC: A setup for mass spectrometry and laser spectroscopy at the research reactor TRIGA Mainz

The research reactor TRIGA Mainz is an ideal facility to provide neutron-rich nuclides with production rates sufficiently large for mass spectrometric and laser spectroscopic studies. Within the TRIGA-SPEC project, a Penning trap as well as a beam line for collinear laser spectroscopy are being installed. Several new developments will ensure high sensitivity of the trap setup enabling mass measurements even on a single ion. Besides neutron-rich fission products produced in the reactor, also heavy nuclides such as 235-U or 252-Cf can be investigated for the first time with an off-line ion source. The data provided by the mass measurements will be of interest for astrophysical calculations on the rapid neutron-capture process as well as for tests of mass models in the heavy-mass region. The laser spectroscopic measurements will yield model-independent information on nuclear ground-state properties such as nuclear moments and charge radii of neutron-rich nuclei of refractory elements far from stability. This publication describes the experimental setup as well as its present status.Comment: 20 pages, 17 figure