The topography of distribution of gaseous radiolytic products in potas
sium picrate crystals was studied. The products were found to form loc
al cavities primarily in the neighborhood of the external surface, edg
es, and large macrodefects of the crystals. Exterior changes of crysta
ls during irradiation were described. Concentration and size of caviti
es, distance between them, and gas pressure in the cavities were deter
mined.