Investigation of Basic Characteristics of Laser Heating in Thermoluminescence and of Laser-Stimulated Luminescence

摘要

A general solution of the heat diffusion equation is presented for the case of a semi-infinite two-layer system that is heated with a localized cw laser beam of Gaussian or uniform circular intensity profile. As an example, this theory is applied to thin layers of a thermoluminescent material on a substrate. The transient thermoluminescence emission response is calculated and compared with experimental results, illustrating the validity the solutions. Applications to transient laser heating of oxide-semiconductor sandwiches are discussed. The theory of heating a semi-infinite two-layer system with a localized C02 laser beam of uniform circular intensity profile is also applied to configurations consisting of thin thermoluminescent LiF; Ti, Mg phosphor layers on borosilicate glass substrates. Two optically stimulable phosphors (MgS:Ce, Sm and CaS;Ce, Sm) have been developed with the goal to eventually apply them to imaging of neutron dose distributions. These phosphors exhibit luminescence emission spectra that are different for UV excitation and for IR stimulation, a property necessary for nearly real-time radiography.