Investigation on the Optimal Fixation Condition of Cylindrical Resonators

The quality factor measurement of the cylindrical resonator is strongly affected by its fixation state. Poor fixation may result in much higher supporting loss, and cause dramatic quality factor reduction. Therefore, the fixation conditions of fused silica cylindrical resonators are investigated in this paper. Different clamping forces are precisely controlled by a torque wrench through the fixture. Different clamping forces are applied to the resonator, resulting in different supporting losses. Experimental results show that the frequency split of the n=1 mode decreases with the tightening torques. The quality factor of the n=2 mode increases from 5.34 million to 9.34 million when the tightening torque increases from 0.5 N·m to 0.8 N·m. The frequency split of the n=1 mode can be a reference parameter for the fixation state. For an optimal fixation condition of the fused silica cylindrical resonator, the sufficient supporting stiffness is suggested to reduce the supporting loss.