Mössbauer Effect inTm169and Total Internal Conversion of the 8.42-keV Transition

Abstract

The absolute yield of the Mössbauer absorption of the 8.42-keV transition in ${\mathrm{Tm}}^{169}$ was determined for a thulium oxide and a thulium metal absorber. The 8.42-keV gamma ray was resolved from the $L$ x rays of erbium by means of a flat lithium fluoride crystal diffraction spectrometer. From the observed Mössbauer absorption effect the total conversion coefficient ${\alpha }_{\mathrm{tot}}=325\mathrm{}\pm 35$ and the magnetic transition rate of $B(M1, \frac{3}{2}\to \frac{1}{2})=5.1\mathrm{}\times {10}^{-2\mathrm{}}{\left(\frac{e\hslash }{2Mc}\right)}^2$ was derived.