Abstract
We demonstrated photon emission during deformation and fracture of axially loaded polycrystalline ice. Emission of visible photons(300-650nm)was confirmed in accordance with crack generation and fracture. Time-resolved photon emission signals are presented along with load changes. After the intense emission occurring at a fracture event, there were several weak emissions which lasted for a few seconds. Emission intensity, including entire spectra ranging from 300 to 650nm, roughly increased with increasing strain energy released by fracture, while scattering in the intensity data showed that emission intensity also strongly depended on the characteristics of each individual crack. Intense emission contained shorter wavelengths than 320nm, indicating that near ultraviolet light is possibly emitted. Emission intensity and spectra may be attributed to microprocesses during fracture. Experimental evidence indicates that the generated electric charge on crack surfaces and at crack tips should have higher energy than that of the electrical potential difference reported previously (Fifolt et al.1993).
