Quasi-rotational bands in neutron deficient doubly even Ba isotopes

Abstract Bombarding targets of 110 Cd, 108 Cd and 106 Cd with 16 O ions of 52.5–66 MeV, the neutron deficient isotopes 124 Ba, 122 Ba and 120 Ba were produced and their ground-state bands were investigated. To identify 120 Ba, which has 18 neutrons less than the most abundant barium isotope, neutron-gamma coincidences had to be applied in addition to charged-particle and gamma-gamma coincidence measurements. The upper limit for the lifetime of the ground state of 120 Ba is 90 sec. In the very light barium nuclei the moment of inertia and the rotational character is still increasing slowly with decreasing neutron number.