DOPPLER-SHIFT MEASUREMENTS OF LIFETIMES OF LOW-LYING LEVELS IN NA23

Lifetimes of low-lying levels in the nucleus Na23 have been measured using the Doppler-shift-attenuation method. Precise level energies have also been deduced. The measured lifetimes or limits on lifetimes {Ex (MeV) τm (psec)} for a number of levels of Na23 are 2.078 (<0.23), 2.391 (0.95±0.20), 2.640 (0.20±0.08), 2.705 (0.20±0.10), 2.982 (<0.07), 3.678 (<0.17), 3.913 (<0.10). The decay properties of the 2.640- and 3.678-MeV levels are discussed in terms of the Nilsson model. © 1969 The American Physical Society.