Luminescence of the calcite under E-beam excitation

Luminescence of calcite from phlogopite-calcite viens, marbles, leuco-granites, apatite-calcite ores, and carbonatites in the spectral range of 200-800 nm under excitation of a nanosecond and subnanosecond e-beam with current densities of 40-500 A/cm² was investigated. It was observed that for all the samples under study have a fast-decaying broadband luminescence in the UV and visible, ranges of spectra with decay time comparable to that of the excitation pulse and a long-lived emission component (decay time over 20ms). The long-lived component has its peak centered around 610-620 nm. Characteristics of the luminescence spectra and decay kinetics for each of the studied calcites were investigated, along with the time-resolved characteristics of the spectra. Luminescence spectra and kinetics with temporal resolution 0,3 ns under electron beam excitation with pulse durations of 0.1, 0.25, and 0.65 ns. It was found that the studied samples are characterized by short time signal rise (~0.3 ns) excitation mechanisms and the types of luminescence centers are discussed.