Abstract
Two possible approaches to spectroscopic measurements of the internal temperature of Y2O2S: Eu are discussed. Methods based on relative Eu3+ fluorescence line intensities are found either to be insufficiently sensitive or to suffer from unavoidable experimental difficulties. The method which is adopted exploits the quadratic shift of the Eu3+5D0→7F0 transition energy with temperature. Controlled-temperature UV- and CR-excited fluorescence measurements establish the temperature calibration, which is then used to obtain the operating temperature of phosphor screens in a demountable CR excitation apparatus and in a tricolor CRT.