The level schemes of Sr and Y isotopes in the mass chains A = 95, 97 and 99

The fission product separator Ostis at the Institut Laue-Langevin at Grenoble (France) was used for the investigation of the beta -decays and the level schemes of short-lived Rb, Sr and Y isotopes with A=95, 97 and 99. The studies in the mass chains 95 and 97 were made using a surface ionization source to provide Rb isotopes whereas the mass chain 99 was investigated using a high temperature ion source. The study of these nuclei close to /sup 98/Sr and /sup 100/Zr where a shape coexistence was evidenced is of great interest. Single gamma - ray and conversion electron spectra, and prompt and delayed gamma - gamma and beta - gamma coincidences were measured. The level schemes of /sup 95/Sr, /sup 95/Y, /sup 97/Sr and /sup 97/Y were established or extended and a preliminary level scheme is given for /sup 99/Y. (21 refs).