Electrostatic extraction of cold molecules from a cryogenic reservoir

Area of Science:

• Atomic and Molecular Physics
• Chemical Physics
• Physical Chemistry

Background:

• Producing beams of cold molecules is crucial for precision measurements and quantum simulations.
• Existing methods often struggle with low densities or limited applicability to polar molecules.

Purpose of the Study:

• To present a novel method for generating continuous, high-density beams of slow and internally cold polar molecules.
• To demonstrate the effectiveness of this method for specific molecules like ND3 and H2CO.

Main Methods:

• Utilizing collisions with a cryogenic helium buffer gas to cool warm molecules.
• Employing an electrostatic quadrupole guide for the extraction of cold molecules.
• Characterizing the molecular beam properties, including flux and density, and rovibrational state populations.

Main Results:

• Achieving fluxes up to (7+/- 4) x 10^10 molecules/s for ND3.
• Reaching peak densities of up to (1.0+/- 0.6) x 10^9 molecules/cm^3 for ND3.
• Attaining single-state populations up to (82+/-10)% for H2CO, monitored by depletion spectroscopy.

Conclusions:

• The presented method successfully delivers continuous, high-density beams of cold polar molecules.
• The source is efficient and applicable to different polar molecules, showing high single-state populations.