A bright, slow cryogenic molecular beam source for free radicals

Area of Science:

• Atomic and Molecular Physics
• Chemical Physics
• Experimental Physical Chemistry

Background:

• Producing beams of free radicals and refractory species is crucial for various experiments.
• Existing methods often face limitations in brightness or applicability.
• Advanced molecular beam sources are needed to overcome these challenges.

Purpose of the Study:

• To demonstrate and characterize a novel cryogenic buffer gas-cooled molecular beam source.
• To assess the source's capability in producing bright beams of free radicals and refractory species.
• To provide detailed beam properties for optimizing experimental conditions.

Main Methods:

• Utilizing a cryogenic buffer gas-cooled system for molecular beam generation.
• Characterizing beam properties including brightness, velocity distributions, and temperatures.
• Performing measurements on the molecular species Strontium Fluoride (SrF).

Main Results:

• Achieved a beam brightness of 1.2 × 10^11 molecules/sr/pulse for SrF in the X(2)Σ(+)(v = 0, N(rot) = 0) state.
• Measured a forward velocity of 140 m/s and a rotational temperature of approximately 1 K.
• Demonstrated favorable comparison with other existing methods for radical and refractory species beam production.

Conclusions:

• The cryogenic buffer gas-cooled source effectively produces bright beams of free radicals and refractory species.
• The source offers excellent beam characteristics suitable for a wide range of experiments.
• Detailed construction information is provided to facilitate adoption by other researchers.