0+ states and absolute E0 and E2 transition rates in even Sn nuclei

States and their depopulating E0 and E2 transitions have been studied in 112,114,116,118,120,122,124Sn. Several methods of γ-ray and electron spectrometry have been employed, including special coincidence techniques for lifetime, conversion electron and double Coulomb excitation measurements. For 114-118Sn the E2 transition probabilities from the first excited 0+ states (02+) are about 20 W.u., which is compatible with a vibrational two-phonon character. Also the E0 transition probabilities from these states are within a factor of two from the vibrational values. For the second excited 0+ states (03+) the corresponding E2 and E0 transition probabilities are considerably smaller. A total of 12 E0 transitions have been observed. The 03+→02+ transition is observed in 114-120Sn and has in 116Sn a a reduced transition probability 1-2 orders of magnitude larger than those of the ground state E0 transitions, which indicates that the 03+ and 02+ states are strong mixtures of components with different < r2>. (author)