High resolution spectroscopy of the hyperfine structure splitting in$^{97,99}$Tc
Résumé
Resonance ionization mass spectrometry is an efficient tool for detecting trace amounts of long-lived radio-isotopes in environmental samples. For absolute quantification a tracer with identical atomic properties and chemical behavior is needed to prevent a possible dependency onto the absolute efficiency for the analytical method. For an application in$^{99}$Tc, the isotope$^{97}$Tc could serve as a potential tracer. Therefore the optical transitions of an efficient ionization scheme for technetium were investigated for the two odd mass isotopes$^{97,99}$Tc, both with a nuclear spin of I= $\frac {9}{2}$ . Using a pulsed, single mode laser with narrow bandwidth, the hyperfine structures (HFS) of two transitions were fully resolved. The observed isotope shift is small in comparison to the width of the hyperfine structure splitting. This is ideal for the application of$^{97}$Tc as tracer isotope for$^{99}$Tc quantification. The evaluation of the observed HFS splitting results in a first experimental value for the magnetic dipole for$^{97}$Tc of μ=+5.82(9) μ$_{N}$ .