Effect of Irradiation on Crystal Defects in Quartz

X-and ¿-irradiation characteristics of optically non-clear natural quartz and electronic grade synthetic crystals have been investigated. In particular, it has been shown how, due to relatively large concentration of crystal imperfections in non-clear natural quartz, a positive frequency shift of crystal resonator on extended irradiation, increased smoky coloration, broad and sharp ESR signals observable at room temperature and increased intensity of thermoluminescence are produced compared to the corresponding characteristics of optically clear quartz crystals. It has been shown, how by increasing the imperfections in non-clear natural quartz still further by neutron irradiation, the frequency characteristics of natural quartz crystals would simulate those of the electronic grade synthetic crystals, and viceversa, by thermal annealing of the latter. Based on the appropriate thermal annealing of electronic grade synthetic crystals, the investigations yield a new way of achieving the much desired radiation hardening of quartz resonators used in satellite-borne frequency standards for space communication.