Het HIE-ISOLDE project in CERN.

The fundamental interactions in atoms are the electromagnetic force, keeping the electrons around the nucleus, the weak force, responsible for nuclear beta decay, and the strong force, holding the protons and neutrons, called the nucleons, together in the nucleus. The electromagnetic force is well known, but the strong- and weak forces are still poorly known. This project aims to learn more specifically about the strong and the weak force. This is not only of fundamental importance, but also for solving questions such as how and where the chemical elements have been made in the universe or what makes the stars shine? Hidden secrets of the atomic nucleus are discovered by studying nuclei with an unusual number of protons and neutrons. Unfortunately, these nuclei are not available on earth as they are radioactive and disappear fast. We have developed a technique to produce these radioactive atoms and to shape them into a beam. The emitted radiation gives direct information on the nuclear properties. But it is also possible to accelerate these atoms to induce reactions. Another possibility is to merge the beam with laser light and observe the excitation of the electrons around the nucleus. Or the radioactive ions can be trapped in electromagnetic fields and their decays can be very precisely studied. All these complementary techniques contribute to fine tune our models and uncover new aspects of the strong and weak force. The radioactive ions are also used as spies in materials as their decay radiation gives information on their environment. The ultra-sensitive methods we develop are also of interest for the production of medical radio-isotopes and for trace detection. The experiments are performed at the radioactive ion beam facility ISOLDE at CERN, Geneva, Switzerland where a new project to substantially improve the intensity and quality of the beams and to accelerate radioactive ion beams to even higher energies (called HIE-ISOLDE) is now in full realization. ISOLDE is a facility dedicated to the production of a large variety of radioactive ion beams for many different experiments in the fields of nuclear and atomic physics, solid-state physics, material science and life sciences. Amongst the existing facilities, ISOLDE presently offers worldwide the widest diversity of radioactive isotopes.

Keywords:Experimental Nuclear Physics, Nuclear Structure, Radioactive Ion Beams, Radioactive decay, Nuclear reactions, Solid-state physics using Nuclear Method

Disciplines:Classical physics, Elementary particle and high energy physics, Other physical sciences