The Isotope Separator On-Line facility (ISOLDE) is a unique source of low-energy beams of radioactive nuclides: those with too many or too few neutrons to be stable. The facility fulfils the old alchemical dream of changing one element into another, enabling the vast landscape of atomic nuclei, including the most exotic species, to be studied.
The proton beam from the Proton Synchrotron Booster (PSB), at energies ranging from 1 to 2 GeV, is directed onto specially developed thick targets, yielding a wide variety of atomic fragments. Different devices are used to ionise, extract and separate the nuclei according to their mass, forming a low-energy beam that is delivered to various experiment stations. These include the ISOLDE Decay Station and the total absorption spectrometer Lucrecia, which measure decay properties, the high-precision mass spectrometer ISOLTRAP, the collinear laser spectroscopy set-ups COLLAPS and CRIS and the laser-polarised instrument VITO, the emission channelling device EC-SLI, designed to study solid-state properties, and the WISArD experiment, which is investigating the weak interaction.
This beam can be further accelerated, allowing various nuclear reaction studies to be performed. In 2015, operation began of a new linear accelerator, HIE-ISOLDE, which could accelerate beams of up to 4.5 MeV/nucleon by 2016 and close to 10 MeV/nucleon when it was completed in 2018. HIE-ISOLDE beams are sent to three experiment stations: an array of high-purity germanium detectors known as Miniball, the ISOLDE Solenoidal Spectrometer , which uses a former MRI magnet, and a third beamline where a large vacuum chamber is used for scattering experiments.
The ISOLDE facility has developed unique capabilities in research with radioactive beams. Over 1300 isotopes of more than 70 elements have been used in a wide range of research domains, from cutting-edge nuclear structure studies, through atomic physics, nuclear astrophysics and fundamental interactions, to solid-state and life sciences. The ISOLDE facility has close to 1000 users, who perform some 50 experiments per year using 15 different beamline instruments.
See a list of experiment set-ups and active ISOLDE experiments.
