An alternative cold cesium frequency standard: the continuous fountain

Area of Science:

• Atomic Physics
• Metrology
• Quantum Optics

Background:

• Primary frequency standards are crucial for timekeeping and scientific research.
• Cesium atomic fountains represent the state-of-the-art in frequency standards.
• Previous designs faced limitations from atomic collisions and pulsed operation instabilities.

Purpose of the Study:

• To report on the design of a novel continuous cesium atomic fountain frequency standard at the Observatoire de Neuchatel (ON).
• To detail specific design features of the continuous fountain, including the atom source, microwave cavity, and modulation scheme.
• To analyze potential frequency biases and their impact on the overall accuracy.

Main Methods:

• Utilizing a continuous fountain of laser-cooled cesium atoms.
• Employing a TE(021) mode microwave cavity for interrogation.
• Implementing a specific microwave modulation scheme tailored for continuous operation.

Main Results:

• The continuous fountain design inherently reduces inaccuracies from atomic collisions.
• The absence of pulsed operation eliminates aliasing effects, enhancing stability.
• Expected accuracy is in the low 10^-15 range with short-term stability of 7x10^-14.

Conclusions:

• The continuous cesium atomic fountain offers significant advantages over pulsed designs.
• The ON frequency standard is projected to achieve state-of-the-art performance.
• This advancement will contribute to improved timekeeping and fundamental physics research.