Levels of Tl206 as Observed at High Resolution with the Tl205(d,p)Tl206 Reaction

Abstract

The energy level structure of ${\mathrm{Tl}}^{206}$ has been investigated with the ${\mathrm{Tl}}^{205}(d,p){\mathrm{Tl}}^{206}$ reaction induced with a 12-MeV beam from a tandem Van de Graaff. The proton spectrum was studied with a broad-range magnetic spectrograph at scattering angles from 20\ifmmode^\circ\else\textdegree\fi{} to 90\ifmmode^\circ\else\textdegree\fi{}. A ground-state $Q$ value of 4.276\ifmmode\pm\else\textpm\fi{}0.005 MeV was measured for this reaction. Forty-four levels were observed. Below 1.5-MeV excitation energy, levels were found at 263, 305, 635, 650, 802, 998, 1117, and 1335 keV excitation. On the basis of the differential-cross-section and angular-distribution measurements, the ground state and 305-keV state appear to belong to the $\frac{{s}_{1}}{\frac{_{2}p_{1}}{2}}$ configuration with spins of $J=0 \mathrm{and} 1$, respectively. The 263- and 650-keV states probably are the $J=2 \mathrm{and} 3$ members, respectively, of the $\frac{{s}_{1}}{\frac{_{2}f_{5}}{2}}$ configuration. The 635- and 802-keV states probably are the $J=2 \mathrm{and} 1$ members, respectively, of the $\frac{{s}_{1}}{\frac{_{2}p_{3}}{2}}$ configuration. Data on the ${\mathrm{Pb}}^{207}(d,p){\mathrm{Pb}}^{208}$ reaction were taken to aid in the interpretation of the data.