Probe of Triple Shape Coexistence In Neutron Deficient Polonium Nuclei

γ‐ray transitions in the neutron deficient 190,197Po nuclei have been identified. The yrast band of 190Po has been extended up to a spin and parity of 14+ and is found to display similar systematic behaviour to isotones 186Hg and 188Pb above the 4+ level, thus confirming its prolate nature. In 197Po the band built upon the 13/2+ isomer has been extended up to a spin and parity of 33/2+, while the non‐yrast side‐band has been observed for the first time. The behaviour of 197Po is found to be similar to that of the nearby even‐mass isotopes, which is consistent with the model in which the i13/2 neutron is weakly coupled to the states in the even‐even core.