Tribothermoluminescence

Abstract

Glass, certain crystals and frits are rendered thermoluminescent by the process of grinding, emitting light of very low intensity. The phenomenon is observed not only in samples of low purity but also in compounds prepared from chemically pure grade materials. Quantitative measurements of light intensity were made by means of a polarization photometer. The particles tested were graded in size by means of a set of screens ranging from 20 to 200 mesh. The results show that the quantity of emitted light depends upon the nature of the substance and the size of the particles, and diminishes slowly with the time after grinding. Common glass tubing crushed to various grain sizes emitted the maximum amount of light when the linear dimensions of the average mesh size fell between 0.015 cm and 0.025 cm respectively.