Results from Gamma Ray and Proton Beam Radiation Testing of Quartz Resonators

This paper summarizes the results of radiation tests on cultured quartz resonators. The tests were conducted to determine the frequency shifts (¿f/f) of the resonators as a result of high and low levels of proton and gamma irradiation. All resonators tested were 5 MHz, 5th overtone, AT cut units manufactured in different lots by Bliley Electric Company from nine bars of Premium-Q, swept, cultured quartz produced by Sawyer Research Products. Generally, the results were as follows: Resonators manufactured from the same bar of cultured quartz showed consistent frequency changes (¿f/f) when subjected to high level gamma radiation. However, this consistency did not exist when the resonators were exposed to low level gamma radiation. For low level radiation no apparent correlation exists between the aluminum content of a resonator and its radiation induced frequency shift (¿f/f). A correlation exists between the low level radiation induced frequency shift (¿f/f) of a resonator and the manufacturing lot in which the resonator was produced. The low level radiation sensitivity of a resonator cannot be extrapolated from high level radiation data. The radiation sensitivities of resonators subjected to low level radiation may be grouped into one of four distinctive signatures. The signatures and the frequency shifts (¿f/f) of resonators subjected to low level proton and gamma radiation are very similar. Radiative preconditioning of resonators reduces the radiation induced frequency shifts (¿f/f) at both high and low levels of gamma and proton radiation.