(Image: A 3-D drawing of the Class A Lab with a photo inset)

The new Class A building at ISOLDE is built to enable UCx target material to be produced and irradiated targets to be handled safely. The Class A laboratory is equipped with fume cupboards, full protective measures and aerosol monitoring. It can handle 150 g UO₂ per day, corresponding to two target containers.

Industrial robots are installed for manipulation of ISOLDE targets, which allows all target changes and manipulations of used target-ion-source systems to be made without human intervention.

A new accelerator, REX-ISOLDE, is put into operation on 31 October 2001. This post-accelerator has opened up new fields of research using radioactive ion beams of higher energies. REX-ISOLDE can provide post-accelerated nuclei covering the whole mass range from He to U for reaction studies and Coulomb excitation with energies up to 3 MeV/u. To this day, REX has accelerated over 100 isotopes of more than 30 different elements.

The new ISOLDE PSB Facility has two isotope separators, a general-purpose separator with one magnet (GPS) and a high-resolution separator with two magnets, similar to the ISOLDE III design. The target handling in the facility is fully automatized with robots. 

On 19 December 1990, at noon, the beam from the Synchrocyclotron (SC) is stopped. At the end of the eighties the decision was taken to shut down the SC.

The ISOLDE programme should, however, continue at CERN and new facility will be built for an external beam from the Proton Synchrotron Booster. 

(image: The basic principle of the RILIS technique: Two laser beams  tuned to transitions between atomic levels - blue and yellow arrows - excite the atoms and a third beam induces the ionization)

The traditional ion sources used at ISOLDE were based on surface ionization and ionization in a plasma. These techniques together with different target matrices gave a large variety of beams for more than 20 years. A major step in improving the purity of and the number of available elements came in 1989 with a new technique based on laser ionization.

A combination of laser beams at wavelengths tuned to the sequence of atomic transitions enables highly efficient resonance excitation and ionization of selected atoms. Isotopes of other elements of the same mass do not interact with the laser radiation. This type of ion source is referred to as a Resonance Ionization Laser Ion Source (RILIS) and is a very powerful tool for the efficient and selective production of radioactive ion beams. The initial off-line RILIS development is then followed by its successful on-line application for laser ionization of ytterbium isotopes at ISOLDE-III on 10 October 1990.

To maximize the use of the Synchrocyclotron (SC) beam time and to meet the requests from the growing physics community using ISOLDE, the ISOLDE collaboration decides to build a second isotope separator of ultra-modern design. The separator design uses a two-stage separation (one 60 degree and one 90 degree magnet) in order to obtain a very high resolution. The target is placed in the SC vault and after the second magnet, the ion beam enters the proton hall, which serves as the new experimental area.

ISOLDE III, is approved at the CERN Research Board session in June 1983 and the final approval to start building the new separator is taken on 10 November of the same year. 

New experiments are installed at ISOLDE II and placed at the three main beam-lines. The photo shows the underground hall UR8 on April 6 1976, which only housed experimental installations. The control desk could be found one floor above.

(image: The ISOLDE II experimental area)

In March 1974, the SC improvement programme is completed and the first beams are directed towards the ISOLDE targets. 

The intensity increase of the external beam up to 1 μA together with new target designs hold their promises and give a considerable increase in the number of isotopes available for experiments.

A new target design and a new layout of the isotope separator is implemented. The target-ion-source unit is placed in the proton beam and the magnet of the isotope separator is placed close to the target. The separated isotopes are then directed towards the experimental setups via a switchyard, which allows researchers to experiment with isotopes of different mass numbers simultaneously.

The first experiment at the reconstructed ISOLDE Facility was performed on March 11, where a target-ion-source system for production of neutron deficient Cs isotopes was used to detect combined beta-delayed proton and alpha emission for the neutron deficient Cs isotopes with mass numbers 118 and 120.

(image: The Synchrocyclotron with the rotating condenser )

The Synchrocyclotron (SC) is shut down for a major reconstruction in 1972, called the SC Improvement Programme (SCIP).  An important part of the upgrade of the SC is to change the frequency system from one based on a tuning fork to a rotating condenser. The extraction system of the beam to ISOLDE is also improved, which means a beam intensity of about two orders higher can be delivered to the ISOLDE target.