Fast-beam laser spectroscopy of neutron-rich barium isotopes

Systematic measurements of the bohr-weisskpf effect at isolde

The hyperfine anomaly gives an insight into the coupling of spin and orbital magnetic moments in the nucleus. More precisely, the nuclear magnetization is expressible through the nuclear wave functions with which is tested not only the magnetic moment operator, but also the tensor product [s×C2]1. The experiment can then be expected to be of value in testing the nuclear structure theory. The greatest value of these measurements is gained when these are made systematically over a large number of isotopes. We propose to initiate a program at ISOLDE to measure the hyperfine anomaly systematically in the heavy alkali elements. The experimental setup to achieve, in particular, a precise measurem…

Atomic beam magnetic resonance apparatus for systematic measurement of hyperfine structure anomalies (Bohr-Weisskopf effect)

Abstract An atomic beam magnetic resonance (ABMR) apparatus has been constructed at Orsay, and has been installed at the CERN PS Booster ISOLDE mass separator facility for “on-line” work with radioactive isotopes in a program to measure hyperfine structure anomalies (the Bohr-Weisskopf effect) over long isotopic chains. The hfs anomalies result from the effect of the spatial distribution of the nuclear magnetization on the atomic hfs interaction. Constructional details of the system are described: emphasis is placed on the measurement of nuclear g-factors by a triple resonance, laser state selected, ABMR method. A precision better than 10−4 for gI values has been obtained in stable atomic b…

Hyperfine structure and isotope shift of the neutron-rich barium isotopes139?146Ba and148Ba

The hyperfme structure and isotope shift in the 6s 2 S 1/2−6p 2P3/2 line of Ba II (455.4 nm) have been measured by collinear fast-beam laser spectroscopy for the neutron-rich isotopes139–146Ba and148Ba. Nuclear moments and mean square charge radii of these isotopes have been recalculated. The isotope shift of the isotope148Ba (T1/2=0.64 s) could be studied for the first time, yieldingδ〈r2〉138,148=1.245(3) fm2.

How Lasers Can Help Probe the Distribution of Nuclear Magnetism

Publisher Summary High-resolution atomic spectroscopy has played an important part in the study of nuclear electric and magnetic structure. Laser spectroscopy has been crucial for the measurement of isotope shifts, which reflect the variations of nuclear charge radii and shapes. High sensitivity and frequency resolution have allowed experiments to be carried out systematically over extensive ranges of stable and radioactive isotopes with lifetime as short as a few milliseconds. While the laser experiments also yield results for nuclear multipole moments, no measurements are obtained of the distribution of nuclear magnetization. Nuclear structure properties can be probed by penetrating elect…

Nuclear moments and charge radii of rare-earth isotopes studied by collinear fast-beam laser spectroscopy

The collinear fast-beam laser technique is being used to measure systematically hyperfine structures and isotope shifts of unstable nuclides in the rare-earth region. This brief report gives a general survey of the results obtained for the even-Z elements64Gd,66Dy,68Er and70Yb, with emphasis on the nuclear spins and moments. They allow a rather complete mapping of the single-particle structure and the development of nuclear deformation in the N > 82 region. The spins, magnetic moments and spectroscopic quadrupole moments of159–169Yb are presented in detail.

Determination of nuclear spins and moments in a series of radium isotopes

Abstract The first investigation of hyperfine structure in radium isotopes has enabled the determination of nuclear spins, magnetic dipole and electric quadrupole moments of the isotopes with mass numbers A = 211, 213, 221, 223, 225, 227 and 229. Isotope shifts in the mass range A = 208−232 have also been measured. These studies were carried out using the technique of on-line collinear fast beam laser spectroscopy.

Nuclear spins, moments, and changes of the mean square charge radii of sup.(140-153)Eu

The hyperfine structures and isotope shifts of 14 isotopes of Eu (Z=63) in the mass range 140≦A≦153, partly with isomeric states, have been measured in the atomic transitions at 4,594 A and 4,627 A, using the technique of collinear fast-beam laser spectroscopy at the ISOLDE facility at CERN. The nuclear spins, the magnetic dipole and electric quadrupole moments, and the changes in the mean square charge radii have been evaluated. These nuclear parameters clearly reflect the effects of theN=82 neutron-shell closure in the single-proton hole states with respect to the semi-magic gadolinium (Z=64), and theN=88−90 shape transition.