Low dose proton radiation sensitivity of quartz resonators

The results of the testing of 4 MHz, 10.24 MHz and 10.95 MHz 3rd overtone SC-Cut quartz crystals confirms the earlier work of Norton and Suter on 5th overtone AT-Cut, SC-Cut crystals. The testing showed that low dose rate radiation sensitivity is manufacturing lot dependent. Frequency variations due to low dose rate proton and gamma ray exposures varied between <1×10^-11 and 4×10^-10 per Rad. The majority of the crystals exhibited radiation sensitivities of 3-5×10^-11 per Rad. The hypothesis that a nonlinear relationship exists between low dose rate and high total dose rate was confirmed. Testing indicated that the majority of crystals exhibited a conditioning effect during successive exposures to low dose radiation. The effect on performance of these types of sensitivities is highly system dependent. However, the capability exists to screen low sensitivity resonators for use in applications where this characteristic is important