PHOSPHOR THERMOMETRY TECHNIQUES FOR THE REALIZATION OF THERMAL STANDARDS*

The possibility of using single-crystals of thermographic phosphors in a new realization of the degree kelvin has been explored. The experimental technique would involve the laser-induced fluorescence of a rare-earth-doped phosphor, the optical decay lifetime of which would be measured relative to an atomic clock, in order to obtain a primary standard of temperature based only on atomic quantities. In principle the technique could provide the first realization of the kelvin over continuous ranges of temperature, without the need for interpolation between fixed thermodynamic transition points. Possible experimental arrangements for carrying out such a realization of the degree kelvin will be discussed