Abstract
Yields of neutron-rich isotopes produced by fast neutron induced fission of
238U were measured at the ISOL set-up Production d’Atomes Radioactifs Riches en Neutrons. A surface ion source was used to ionize selectively elements with low ionization potentials. In order to observe also the most n-rich isotopes, the identification was achieved by a combined measurement of β- and γ-rays and β-delayed neutrons. The flux of fast neutrons inducing fission was generated by a 1 μA beam of 26 MeV deuterons stopped in a graphite converter. The target was a standard ISOLDE type
238UC
X
/graphite (50 g/cm
2) heated by a tantalum oven to about 2050 °C. A large variety of radioactive isotopes could be determined quantitatively. Production rates measured for Rb and Cs isotopes are presented here.