Study of theTl203(nth, γ)Tl204Reaction

The gamma-ray spectrum following the capture of thermal neutrons in natural thallium has been observed with a lithium-drifted germanium detector. The energies and approximate intensities of 42 transitions in the energy range 4 to 6.6 MeV have been determined. From these transitions a level scheme and neutron-separation energy of ${\mathrm{Tl}}^{204}$ have been obtained. Several transitions in the low-energy region have also been observed and a decay scheme has been constructed on the basis of energy considerations.