The search for super-heavy ions

The present the search for heavy nuclei, they briefly draw a historical review of the production of heavy isotopes and then describe the means and possibilities the French GANIL (national great accelerator of heavy ions) facility offers. The different steps of the experimental process are described: production, selection, detection and identification. The production cross-sections are so weak that every parameter involved in the production process has to be optimized. It appears that the limit of our technological knowledge has been reached and unless an important technical step forward it seems impossible to go down below the pico-barn (10 sup - sup 1 sup 2 *10 sup - sup 2 sup 4 cm sup 2) for production cross-sections. The 2 remaining ways to improve the situation are: 1) to increase the intensity of the incident particle beam (today we have < 10 sup 1 sup 3 pps), this implies that an important development about accelerators and ion sources has to be achieved, 2) the other way is to use radioactive ion beams, the excess of neutrons of the incident ion gives a better production rate and will allow us to reach the neutron-rich part of the stability island. (A.C.)