Decay of Ta177 and Lu177 to Levels in Hf177

Abstract

The decays of ${\mathrm{Ta}}^{177}$ and ${\mathrm{Lu}}^{177}$ to levels in ${\mathrm{Hf}}^{177}$ have been investigated with beta-ray spectrometers, NaI(Tl) gamma-ray spectrometers, and fast coincidence and angular correlation techniques. Energy levels in ${\mathrm{Hf}}^{177}$ have been characterized according to their energy (kev), the Nilsson asymptotic quantum numbers ($N{n}_z\Lambda$), the total angular momentum and its component along the symmetry axis ($I, K$), and the parity ($\pi$) as follows: $0[514 \frac{7}{2}, \frac{7}{2}-]$; $112.97[514 \frac{9}{2}, \frac{7}{2}-]$; $249.7[514 \frac{11}{2}, \frac{7}{2}-]$; $321.34[624 \frac{9}{2}, \frac{9}{2}+]$; $447.9[624 \frac{11}{2}, \frac{9}{2}+]$; $420.95[642 \frac{3}{2}, \frac{3}{2}+]$; $488.8[642 \frac{5}{2}, \frac{3}{2}+]$; $585.8[642 \frac{7}{2}, \frac{3}{2}+]$; $509.0[512 \frac{5}{2}, \frac{5}{2}-]$; $605.5[512 \frac{7}{2}, \frac{5}{2}-]$; $746.04[633 \frac{7}{2}, \frac{7}{2}+]$; $848.2[633 \frac{9}{2}, \frac{7}{2}+]$; and $1058.38[503 \frac{7}{2}, \frac{7}{2}-]$. The levels at 447.9, 488.8, and 585.8 kev are tentative. The spins and parities have been uniquely determined by...