Fluorescence Spectroscopic Characteristics of Tb3+ and Sm3+ in LiCl-KCl Molten Salts

Laser-induced fluorescence was applied for the detection of lanthanide ions such as Tb3+ and Sm3+ in a pyrochemical processing. The fluorescence signals of Tb3+ and Sm3+ in LiCl-KCl molten salts were successfully observed at room temperature. Moreover, the fluorescence method was identified to be sensitive enough to detect a trace of Eu2+, originated from a reduction of Eu3+ contained in a LiCl-KCl eutectic reagent at a given high temperature molten salt condition. The non-destructive and direct fluorescence measurement can be an alternative method in on-line and in situ determination of the species and concentrations of lanthanides in a molten salt along with absorption measurement.