HIGH-RESOLUTION LOSS SPECTROSCOPY OF QUARTZ

Naval Research Laboratory (NRL) scientists have developed an instrumen t that has extreme sensitivity to energy dissipation in mechanical res onators. While previous instruments measured loss to one part in ten, the new instrument measures mechanical loss to one part in 10(4) or be tter. Low defect levels, that result in small residuals of loss above background, are detectable because of the instrument's high resolution . We have used the resonator to examine loss spectroscopy of quartz re sonators vibrating in flexure. The resonators have a large background loss that peaks up at low temperature. Although the peak very closely fits a Debye-like equation, the derived parameters, such as the decay time prefactor, are unphysical.