Laser spectroscopy for nuclear structure physics

Atomic physics techniques for the determination of ground-state properties of radioactive isotopes are very sensitive and provide accurate masses, binding energies, Q-values, charge radii, spins and electromagnetic moments. Many fields in nuclear physics benefit from these highly accurate numbers. They give insight into details of the nuclear structure for a better understanding of the underlying effective interactions, provide important input for studies of fundamental symmetries in physics, and help to understand the nucleosynthesis processes that are responsible for the observed chemical abundances in the Universe. Penning-trap and storage-ring mass spectrometry as well as laser spectroscopy of radioactive nuclei have now been used for a long time but significant progress has been achieved in these fields within the last decade. The basic principles of laser spectroscopic investigations, Penning-trap and storage-ring mass measurements of short-lived nuclei are summarized and selected physics results are discussed.

https://iopscience.iop.org/article/10.1088/0031-8949/2013/T152/014017/pdf

Precision Atomic Physics Techniques for Nuclear Physics with Radioactive Beams

The structure of nuclear isomeric states is reviewed in the context of their role in contemporary nuclear physics research. Emphasis is given to high-spin isomers in heavy nuclei, with [Formula: see text]. The possibility to exploit isomers to study some of the most exotic nuclei is a recurring theme. In spherical nuclei, the role of octupole collectivity is discussed in detail, while in deformed nuclei the limitations of the K quantum number are addressed. Isomer targets and isomer beams are considered, along with applications related to energy storage, astrophysics, medicine, and experimental advances.

https://iopscience.iop.org/article/10.1088/0034-4885/79/7/076301/pdf

Review of metastable states in heavy nuclei

Over three and a half decades of collinear laser spectroscopy and the COLLAPS setup have played a major role in the ISOLDE physics programme. Based on a general experimental principle and diverse approaches towards higher sensitivity, it has provided unique access to basic nuclear properties such as spins, magnetic moments and electric quadrupole moments as well as isotopic variations of nuclear mean square charge radii. While previous methods of outstanding sensitivity were restricted to selected chemical elements with special atomic properties or nuclear decay modes, recent developments have yielded a breakthrough in sensitivity for nuclides in wide mass ranges. These developments include the use of bunched beams from the radiofrequency quadrupole cooler–buncher ISCOOL, which allows a suppression of background by several orders of magnitude. Very recently, the combination of collinear laser spectroscopy with the principle of laser resonance ionisation took shape in the new CRIS setup, providing a very selective and efficient detection of optical resonance. We outline the basic experimental developments and discuss important results on nuclei or chains of isotopes in different mass ranges.

/pdf/collinear-laser-spectroscopy-at-isolde-new-methods-and-58447syfu6.pdf

Collinear laser spectroscopy at ISOLDE: new methods and highlights

This article summarizes the current specifications and the latest features of the CERN-ISOLDE resonance ionization laser ion source (RILIS). This includes a description of the optical layout and the newly designed reference system. The ionization schemes for the laser ionized beams at ISOLDE are tabulated, including six new elements. All RILIS schemes are also made publicly available in the RILIS elements on-line database. Finally, we announce a paradigm shift in RILIS operation – the combination of a machine protection and a monitoring and control system has enabled on-call operation of the laser ion source for selected beams in 2014 and has become the standard mode of operation in 2015.

/pdf/laser-ion-beam-production-at-cern-isolde-new-features-more-yhv4zjeg6g.pdf

Laser ion beam production at CERN-ISOLDE: New features – More possibilities

Collinear laser spectroscopy was performed on the $^{80}\mathrm{Ga}$ isotope at ISOLDE, CERN. A low-lying isomeric state with a half-life much greater than $200$ ms was discovered. The nuclear spins and moments of the ground and isomeric states and the isomer shift are discussed. Probable spins and parities are assigned to both long-lived states (${3}^{\ensuremath{-}}$ and ${6}^{\ensuremath{-}}$) deduced from a comparison of the measured moments to shell-model calculations.

/pdf/discovery-of-a-long-lived-low-lying-isomeric-state-in-ga-80-3o5cbb07fc.pdf

Discovery of a long-lived low-lying isomeric state in Ga-80

1 Schuster Building, University of Manchester, Brunswick Street, Manchester, M13 9PL, UK 2 Instituut voor Kernen Stralingsfysica, KU Leuven, B-3001 Leuven, Belgium 3 Physics Department, CERN, CH-1211 Geneva 23, Switzerland 4 School of Physics and Astronomy, The University of Birmingham, Birmingham, B15 2TT, UK 5 Department of Physics, University of Jyväskylä, PB 35 (YFL) FIN-40014 Jyväskylä, Finland

/pdf/collinear-laser-spectroscopy-of-manganese-isotopes-using-4vz00vrmgi.pdf

M. M. Rajabali

Papers

Discovery of a long-lived low-lying isomeric state in Ga-80

Collinear laser spectroscopy of manganese isotopes using optical pumping in ISCOOL.