B. S. Lunin

Influence of internal adhesive joints on the residual atmosphere in vacuum devices

The influence of outgassing from internal adhesive joints of vacuum devices on the residual atmosphere in them was analyzed. It is shown that the residual atmosphere in a sealed vacuum device with internal adhesive joints and a built-in getter consists mainly of hydrocarbons. Methods for improving the vacuum inside the cases of devices are considered. It is concluded for the first time that degassing of adhesive seams in a device in vacuum at an elevated temperature allows the outgassing of hydrocarbons to be reduced by several orders of magnitude.

Balancing of hemispherical resonator gyros by chemical etching

A procedure for balancing the four lower harmonics of the mass distribution defect in a fused quartz hemispherical toothless resonator of a hemispherical resonator gyroscope is considered. Chemical etching of unbalanced mass from the surface of a partially immersed resonator is done in accordance with analytically calculated angle of the resonator rotation about the axis of symmetry, inclination and depth of the resonator immersion into a chemical bath, and the time of chemical etching. It is shown that the proposed method significantly reduces the balancing time and labor input as compared with ion plasma etching.

Static balancing of metal resonators of cylindrical resonator gyroscopes

A technique based on electrochemical etching of metal is suggested for balancing the first four harmonics of nonuniform mass distribution in a metal cylindrical toothless resonator for a cylindrical resonator gyroscope (CRG). An algorithm for removing mass from the resonator surface has been designed with allowance made for analytically calculated angle and depth of the resonator inclined immersion into an electrochemical bath and its rotation about the cylinder axis of symmetry.

Preparation of silica glass with a low degree of internal friction

Based on the analysis of dissipative processes in solids, the factors which determine the magnitude of internal friction in silica glasses have been highlighted and the main principles of the synthesis of silica glass with low internal friction have been stated. In accordance with the developed principles, the process for the preparation and vacuum melting of the silica raw material has been implemented. The results of the study of the prepared glass specimens, which was performed based on the procedure for the measurement of the oscillation decay time, have shown a sufficiently a low degree of internal friction.

Influence of nonuniform thickness of hemispherical resonator gyro shell on its unbalance parameters

Formulas for the unbalance components of the hemispherical resonator gyro (HRG) with a shell of variable thickness in meridian direction are obtained. Various laws of thickness reduction from the pole to the edge are considered. It is shown that for the second form of excited oscillations, relative error in unbalance components (with the thickness variation neglected) can reach 10–15%. The obtained formulas for unbalance components, taking into account the variable thickness of the shell, can significantly improve the accuracy of HRG balancing, which is the most important process in the manufacture of medium and high precision devices.

Internal Friction in Quartz Glass Made Using Natural and Synthetic Raw Material

The sequence of operations involved in the fabrication of samples of quartz glass from highly enriched natural raw material and synthetic silicon dioxide is described and implemented. Attention is focused on purifying the raw material and maintaining a clean regime during the glass fabrication process. It is shown that synthetic raw material is best for obtaining quartz glass with low internal friction.