A Novel Method for Rubidium Bulb Bonding and Key Characterization for Future Space Clocks

Area of Science:

• Materials Science
• Atomic Physics
• Aerospace Engineering

Background:

• RF-discharge lamps are critical for rubidium atomic frequency standards (RAFSs).
• Reliable operation of atomic clocks depends on precise thermal and structural control of the rubidium (Rb) bulb.
• The potting material for the Rb bulb is crucial for thermal contact and temperature regulation.

Purpose of the Study:

• To investigate indium metal as a superior alternative to epoxy for Rb bulb bonding in atomic clocks.
• To evaluate the thermal and mechanical properties of indium for space-based applications.
• To assess the potential of indium for enhancing the reliability of Rb atomic clocks.

Main Methods:

• Design and simulation of indium-based Rb bulb mounting.
• Implementation and characterization of indium bonding.
• Testing of the indium-bonded Rb bulb in a simulated environment.

Main Results:

• Indium demonstrates significant thermal advantages over conventional space-qualified epoxies.
• Indium facilitates easier bonding and unbonding, crucial for maintenance and repair.
• Successful characterization and testing confirm the viability of indium for Rb clock applications.

Conclusions:

• Indium metal is a highly suitable replacement for epoxy in Rb bulb bonding for space and ground atomic clocks.
• The thermal properties and re-workability of indium offer enhanced performance and longevity for atomic frequency standards.
• Indium's unique characteristics present opportunities for broader applications in demanding environments.