The Isotope mass 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 in fact the old alchemical dream of changing one element into another. It permits the study of the vast territory of atomic nuclei, including the most exotic species.

The 1.4 GeV proton beam from the Proton Synchrotron Booster (PSB) is directed into specially developed thick targets, yielding a large variety of atomic fragments. Different devices are used to ionize, extract and separate nuclei according to their mass, forming a low-energy beam that is delivered to various experimental stations.

This beam can be further accelerated, allowing various nuclear reaction studies. A newer linear accelerator HIE-ISOLDE began construction in 2015, accelerated beams up to 4.5 MeV/nucleon by 2016 and then close to 10 MeV/nucleon when completed in 2018. HIE-ISOLDE beams are sent to three experimental stations: an array of high purity germanium detectors known as Miniball, the ISOLDE Solenoid Spectrometer, which uses a former MRI magnet and a third beam line where a large vacuum chamber is used for scattering experiments.

The ISOLDE facility has gathered 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, fundamental interactions, to solid state and life sciences. The ISOLDE facility has more than 900 users who perform about 50 experiments per year using 15 different beamline instruments. 

See a list of experimental setups or active ISOLDE experiments