The decay of Au194

Abstract

Abstract The decay of Au 194 was investigated by the use of high resolution spectrometers for the measurements of the conversion spectrum and a double lens spectrometer for coincidence measurements. By careful analysis of the conversion spectrum, which was recorded at a resolution of ≈0.2%, it was possible to identify more than 100 transitions in Pt 194 . The use of strong sources and a double counter operated in coincidence made possible the detection of lines of intensity only 10 −5 times that of the strongest line. Multipolarities could be found from K/L ratios for a few low energy transitions and some information could also be extracted from a comparison with results of previous gamma ray work. Energies of the strongest lines were measured absolutely by means of an iron free double focusing instrument, and further energy determinations were made relatively to these lines. The standard error of the measurements was frequently as low as 2 parts in 10 4 . A complete set of energy sums was computed in order to survey the possibilities of cascade-crossover combinations. The reliability of the numerical relationships was investigated statistically, and it was shown that a reasonably unique level scheme could be constructed on the basis of energies, although the positions of transitions remained to some extent ambiguous. The results of 79 coincidence experiments are reported, and when analyzed these data lead to a level scheme in agreement with the conclusions of the other approach. Furthermore, these experiments helped in deciding the location of transitions. Evidence for at least two 0 + states was found. The discovery of a level at 923 keV, probably of 4 + character, revealed a close analogy with the level scheme of Pt 192 . The interpretation of this level as a three-phonon state is in agreement with theory.