Citation
Abstract
We present preliminary design features for a second-generation thermomechanically compensated sapphire resonator. Developed a few years ago, the 77 K compensated sapphire oscillator (CSO) resonator showed a quality factor of Q = 2 £ 106 at an operating temperature of 85 K, enabling a frequency stability of –f=f < 1 £ 10¡13. The new design promises a frequency stability of parts in 1015 with cooling provided by a cryocooler consuming several hundred watts or less. Optimization of the resonator design for a temperature of 40 K results in a mechanical tuning-rate requirement (MHz/mm) reduced by a factor of 8, allowing for reduced electromagnetic (EM) fields at the surface of the sapphire and reduced sensitivity to mechanical deformation. This optimized EM design is implemented in a selfassembling mechanical design that allows easy disassembly for cleaning, together with a first-order cancellation for expected mechanisms of physical creep. The new design is expected to share the very short thermal time constants characteristic of the 10 K and 77 K CSO resonators, thus allowing efiective compensation of rapid temperature fluctuations.
Keywords
Details
- Volume
- 42-143
- Published
- November 15, 2000
- Pages
- 1–9
- File Size
- 311.9 KB