| The decay properties of the low-lying levels of 207Pb and 116Cd have been investigated with the (n,n' gamma) reaction. Gamma-ray excitation functions, angular distributions, and coincidence measurements were used to establish the lower-energy portions of the level schemes of both isotopes. The Doppler-shift attenuation method was employed for measurements of level lifetimes in the feratosecond to picosecond range. Many new levels and new transitions from previously known states have been established, and spin-parity assignments and multipole mixing ratios have been measured. In addition, lifetimes and reduced transition probabilities for some states have been determined.; In 207Pb, the expected sextuplet of states from the 3 - ⊗ f-15/2 coupling is suggested, and the properties of the weak-coupled states are examined. Based on E1 transition rates observed in this study, the 2 + and 4+ members of the two phonon quartet from the 3- ⊗ 3- in 208Pb were assigned.; The 116Cd nucleus shows interesting properties in that two additional 0+ and 2+ states are observed along with the two-phonon triplet. These states are generally referred to as intruder states and affect the properties of the multiphonon states. The three-phonon states are expected at about 2 MeV and enhanced E2 transition to the two-phonon states are anticipated. From this (n,n'gamma) study of 116Cd, three-phonon candidates were suggested based on energy, spin, and E2 transition rates arguments. Negative-parity states resulting from the 2+ ⊗ 3- coupling are expected to decay by enhanced E1 and E2 transitions. The properties of the observed negative-parity states were examined and the 4- and 5- members of the quintuplet were suggested. |
