Table of experimental nuclear ground state charge radii: An update

A ‘year-2001’ set of nuclear quadrupole moments, Q, is presented. Compared to the previous, ‘year-1992’ set, a major revision of the value or a considerable improvement of the accuracy is reported for 6 3Li, 7N, 19 9F (197 keV, I = 5/2), 11Na, 13Al, 21Sc, 22Ti, 26Fe (14 keV, I = 3/2 Mossbauer state), 31Ga, 32Ge, 77 34Se (250 keV, I = 5/2 state), 35Br, 36Kr, 37Rb, 39Y, 40Zr, 100 45Rh, 50Sn (24 keV, I = Mossbauer state), 53I, 54Xe, 55Cs and 83Bi.

Spectroscopic nuclear quadrupole moments

The experimental and theoretical evidence for intrinsic reflection-asymmetric shapes in nuclei is reviewed. The theoretical methods discussed cover a wide spectrum, from mean-field theory and its extensions to algebraic and cluster approaches. The experimental data for nuclear ground states and at low and high spin, cited as evidence for reflection asymmetry, are collected and categorized. The extensive data on electric dipole transition moments and their theoretical interpretation are surveyed, along with available data on electric octupole moments. The evidence for reflection-asymmetric molecular states in light nuclei is summarized. The application of reflection-asymmetric theories to descriptions of the fission barrier, bimodal fission, superdeformation, and hyperdeformations is reviewed, and some other perspectives in the wider context of nuclear physics are also given. [S0034-6861(96)00102-X]

Intrinsic reflection asymmetry in atomic nuclei

Signatures of criticality in the evolution of the nuclear ground-state shapes across the NxZ plane are discussed. Attention is paid to specific data indicating sudden structural changes in various isotopic and isotonic chains of medium-mass and heavy even-even nuclei, as well as to diverse theoretical aspects of the models used to describe these changes. The interacting boson model and the geometric collective model, in particular, are discussed in detail, the former providing global predictions for the evolution of collective observables in nuclei between closed shells and the latter yielding a parameter-efficient description of nuclei at the critical points of shape transitions. Some issues related to the mechanism of first- and second-order quantum phase transitions in general many-body systems are also outlined.

Quantum phase transitions in the shapes of atomic nuclei

Laser spectroscopy for nuclear structure physics

Laser-spectroscopy measurements of 72–96Kr spins, moments and charge radii

Xenon isotopes far from stability studied by collisional ionization laser spectroscopy

High-resolution laser spectroscopy for the study of nuclear sizes and shapes J Billowes and P Campbell High resolution laser spectroscopy of atomic systems R C Thompson High-resolution laser spectroscopy of Fr ns and nd Rydberg levels E Arnold, W Borchers, M Carre et al. Resonance laser ionization of atoms for nuclear physics V N Fedosseev, Yu Kudryavtsev and V I Mishin Laser detection of single atoms Viktor I Balykin, G I Bekov, V S Letokhov et al. Precision atomic physics techniques for nuclear physics with radioactive beams Klaus Blaum, Jens Dilling and Wilfried Nortershauser Resonance ionization spectroscopy on a fast atomic ytterbium beam

Resonance ionization spectroscopy on a fast atomic ytterbium beam

Resonance ionization spectroscopy in collinear geometry has been successfully applied to a fast beam of ytterbium atoms. The atoms were excited stepwise into a Rydberg state by pulsed laser light, ionized in an electrical field and deflected onto a secondary electron detector. The efficiency was 1*10-5 detected ions per incoming atom on a background from collisional ionization of 1*10-8. The technique has been exploited for the measurement of hyperfine structures and isotope shifts of unstable ytterbium isotopes, in particular 157Yb, 159Yb and 175Yb.

/pdf/resonance-ionization-spectroscopy-on-a-fast-atomic-ytterbium-1iau1z7yrj.pdf

The hyperfine structure (hfs) and isotope shift (IS) in the isotopic chain of the radioactive element radon have been studied for the first time. The measurements were carried out by collinear fast-beam laser spectroscopy at the mass separator facility ISOLDE at CERN. The IS between 16 isotopes in the mass range 202≦A≦222 and the hfs of 7 odd-A isotopes were determined in the transitions 7s [3/2]2-7p [5/2]3 (745 nm) of Rn I. The nuclear spins and moments, as well as the observed inversion of the odd-even staggering for218–222Rn, can be associated with the effects of octupole instability around N=134.

/pdf/hyperfine-structure-and-isotope-shift-investigations-in202-4h8ao2imsa.pdf

W Borchers

Papers

Laser-spectroscopy measurements of 72–96Kr spins, moments and charge radii

Xenon isotopes far from stability studied by collisional ionization laser spectroscopy

Resonance ionization spectroscopy on a fast atomic ytterbium beam

Resonance ionization spectroscopy on a fast atomic ytterbium beam

Hyperfine structure and isotope shift investigations in202–222Rn for the study of nuclear structure beyond Z=82