Abstract

At ISOLDE the majority of radioactive ion beams are produced using the resonance ionization laser ion source (RILIS). This ion source is based on resonant excitation of atomic transitions by wavelength tunable laser radiation. Since its installation at the ISOLDE facility in 1994, the RILIS laser setup has been developed into a versatile remotely operated laser system comprising state-of–the-art solid state and dye lasers capable of generating multiple high quality laser beams at any wavelength in the range of 210–950 nm. A continuous programme of atomic ionization scheme development at CERN and at other laboratories has gradually increased the number of RILIS-ionized elements. At present, isotopes of 40 different elements have been selectively laser-ionized by the ISOLDE RILIS. Studies related to the optimization of the laser–atom interaction environment have yielded new laser ion source types: the laser ion source and trap and the versatile arc discharge and laser ion source. Depending on the specific experimental requirements for beam purity or versatility to switch between different ionization mechanisms, these may offer a favourable alternative to the standard hot metal cavity configuration. In addition to its main purpose of ion beam production, the RILIS is used for laser spectroscopy of radioisotopes. In an ongoing experimental campaign the isotope shifts and hyperfine structure of long isotopic chains have been measured by the extremely sensitive in-source laser spectroscopy method. The studies performed in the lead region were focused on nuclear deformation and shape coexistence effects around the closed proton shell Z = 82. The paper describes the functional principles of the RILIS, the current status of the laser system and demonstrated capabilities for the production of different ion beams including the high-resolution studies of short-lived isotopes and other applications of RILIS lasers for ISOLDE experiments.

Highlights

  • The physical composition and intensity of ion beams, produced at radioactive ion beam facilities such as ISOLDE depends strongly on the type of ion source used to ionize the isotope of interest

  • The ongoing resonance ionization laser ion source (RILIS) development is focused on three main areas: Laser technologies—for improved reliability, stability, efficiency and spectral resolution

  • The laser ion source and trap (LIST) concept, proposed in 2003, required more than 10 years of modification and characterization until it became operational at ISOLDE in 2014

Read more

Summary

Introduction

The physical composition and intensity of ion beams, produced at radioactive ion beam facilities such as ISOLDE depends strongly on the type of ion source used to ionize the isotope of interest. This highly sensitive laser spectroscopy method for the study of unstable isotopes was pioneered at LNPI [21].

Laser resonance ionization of atoms
Ionization in a hot cavity
RILIS laser system
Ion source for highest selectivity
Hybrid plasma-laser ion source
Ion beam production
54–62 Stable 56–70 57–78
Separation of nuclear isomers
In-source RIS
Other applications of the RILIS laser installation
Conclusions and outlook
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call