LEVEL DENSITIES EXTRACTED FROM FIRST-GENERATION GAMMA-RAY SPECTRA

The level density of low-spin states (0 - 10 ($) over bar h) in Dy-162 has been determined from the ground state up to approximately 6 MeV o f excitation energy. Levels in the excitation region up to 8 MeV were populated by means of the Dy-163(He-3,alpha) reaction, and the first-g eneration gamma-rays in the decay of these states have been isolated. The energy distribution of the first-generation gamma-rays provides a new source of information about the nuclear level density over a wide energy region. A broad peak is observed in the first-generation spectr a, and we suggest an interpretation in terms of enhanced M1 transition s between different high-j Nilsson orbitals.