EN
The numerical model of ionization of short-lived nuclides in spherical hot cavities is presented. Two different cavity configurations are considered: one of them (the hemispherical one) resembles that known from already existing ion sources while the other (closer to the full sphere) could be more efficient for short-lived isotopes. Changes of ionization efficiency with the half-life period as well as with the particle average sticking time are presented and discussed. Influence of the extraction opening radius on ionization efficiency is also under investigation.