The decay of 160Tb to levels in 160Dy

Abstract

The gamma radiation associated with the beta decay of X6°Tb to levels in Xe°Dy has been studied with curved-crystal and Ge(Li) spectrometers. Eight previously unreported transitions were observed with energies 237.6384-0.086 keV, 242.54-0.8 keV, 246.489i0.016 keV, 349.944-0.11 keV, 432.74-0.6keV, 10054-1 keV, 1069.14-0.4keV and 1300.04-0.8keV. The existence of transitions at 176, 379, 486, 872 and 1286 keV has been confirmed. Gammagamma coincidence studies employing two Ge(Li) detectors have led to a decay scheme which is essentially that given by previous investigators with the addition of levels at 1155.8, 1288.7 and 1535.2 keV. The level at 1155.8 keV has been identified as the 4 + member of the gamma-vibrational band. No evidence was obtained for the population of any K~ = 0 ÷ beta-vibrational levels from the decay of Xa°Tb.

Gamma Ray Intensity and Angular Correlation Measurements in 160Dy

“…Thus, in summary, our measurements for the relative intensities of y rays in 160Dy are found to be in good agreement with those obtained by Ludington et al (1968). We have established the multipolarities of the 197, 215, 299, 879 and 962 keY y rays to be E2 +(O'2±O'2)%M3, El +(2·5~~:~)%M2, El +(2~~)%M2, Ml + (99 ± 1) % E2 and Ml +(98 ± 1) % E2 respectively.…”

“…Our measurements of the relative intensities of the y rays, as obtained with a 7·77 cm 3 Ge(Li) detector, are given in Table 1 along with those determined by Ludington et al (1968). In general, there is good agreement between the two sets of results.…”

“…Dysprosium-160 is a doubly even nucleus in the deformed region and its level scheme has been studied by many workers (Nathan 1957;Ofer 1957;Arns et al 1959;Ewan et al 1961;Kundig 1961;Michaelis 1963;Gupta and Saha 1965) using scintillation, curved-crystal and magnetic spectrometers. Recently the decay scheme of 160Tb has been investigated using a Ge(Li) spectrometer (Ludington et al 1968;Keller and Zganjar 1970;McAdams and Ottesson 1972;Roehmer 1973). While several new y rays proposed by Ludington et al have been subsequently verified by Keller and Zganjar and by McAdams and Ottesson, there is some disagreement between the relative intensities of some of the y rays as measured by these workers.…”