Rubidiumklokker

Rubidiumklokker are atomic clocks that use the hyperfine transition of rubidium-87 atoms as a reference to keep time. The key transition lies at about 6.8 GHz, commonly cited as around 6.834 GHz. In a typical device, rubidium atoms are contained in a small glass cell (or a beam tube) and interrogated by microwave radiation near this resonance. Through optical pumping and fluorescence detection, the atomic population is monitored, and the resulting signal is used to stabilize a local oscillator, usually a quartz oscillator, to remain in resonance with the atomic transition.

The stabilized oscillator provides a precise and stable frequency output that serves as a time reference. Rubidium clocks are a form of compact, robust atomic clock suitable for use as secondary standards and in timing infrastructure. They offer excellent short-term stability and are generally more compact and cost-effective than primary cesium standards, though they typically do not reach the long-term accuracy of high-end cesium or optical clocks.

Applications include telecommunications networks, data centers, calibration laboratories, and field timing where a reliable, inexpensive frequency reference is needed. Modern rubidium standards are available in portable and rack-mounted formats, and are often integrated into timing modules for GPS receivers, network synchronization, and test equipment.

Advantages include small size, low power consumption, good short-term stability, and relatively low cost. Limitations involve sensitivity to temperature and magnetic fields, environmental conditions, and component aging. Among atomic clocks, rubidium standards are valued for practicality and reliability rather than ultimate long-term accuracy.