Emission kinetics of light, sound, and radio waves from single-crystalline quartz after impact on its surface

A steel striker impacting the surface of single-crystalline quartz generates strain waves and their related acoustic and electromagnetic emissions. Simultaneously, microcracks with free excited SiO$\bullet$ radicals at their edges appear in the single crystal. The relaxation of the electronic excitation causes bursts of fractoluminescence. The intensity of the bursts is proportional to the microcrack surface area. It is found that the linear sizes of microcracks vary from 15 to 70 $\mu$m. Cracking changes the slope of the time dependences of the acoustic and electromagnetic emission intensities. The microcrack size distribution obeys a power law with an exponent of about two.