Cold atom microwave clock based on intracavity cooling in China space station

Area of Science:

• Atomic, Molecular, and Optical Physics
• Space Science and Technology
• Metrology

Background:

• High-precision atomic clocks are crucial for autonomous space-time-frequency systems.
• Existing space-borne atomic clocks have limitations in frequency stability and accuracy.
• Advancements are needed for long-term, reliable space operations.

Purpose of the Study:

• To design and test a novel space cold atom clock using an intracavity cooling scheme.
• To evaluate the clock's performance characteristics and reliability for space station deployment.
• To demonstrate the feasibility of high-precision atomic clocks in a microgravity environment.

Main Methods:

• Development of a space cold atom clock employing an intracavity cooling technique.
• In situ interaction of cold atoms with microwaves within a resonant cavity.
• Testing and analysis of the clock's operational characteristics and engineering prototype performance.

Main Results:

• The space cold atom clock achieved a fractional frequency stability of 1.1 × 10^-12 τ^-1/2.
• A long-term stability of 2.5 × 10^-15 was reached at 200,000 seconds.
• The design provides robust technical and data support for future orbital operations.

Conclusions:

• The intracavity cooling scheme enables enhanced atomic clock performance in space.
• The developed clock meets the stringent requirements for operation on the China space station.
• This technology supports the advancement of autonomous space-time-frequency systems.