Cold Beam of $^7$Li$^4$He Dimers

TL;DR

This paper presents a method to produce a high-flux, cold beam of $^7$Li$^4$He dimers using post-nozzle seeding in a supersonic helium expansion, supported by quantum scattering simulations.

Contribution

The study introduces a novel technique for generating a high-flux, ultracold molecular beam of lithium-helium dimers and compares experimental results with ab-initio simulations.

Findings

Achieved a molecular beam flux of approximately 10^11 dimers/sec.

Measured a longitudinal temperature of about 13 mK.

Validated Monte Carlo simulations with experimental data.

Abstract

We demonstrate an approach for producing a high flux beam of $^7$Li$^4$He dimers by performing post-nozzle seeding of a lithium beam into a supersonic helium expansion. The molecular beam has a longitudinal temperature of 13(6) mK and a continuous flux on the order of $10^{11}$ dimers/s. Monte Carlo simulations of molecular formation based on ab-initio quantum scattering calculations are carried out and compared to the experimentally observed molecular flux. Extensions of this work could lead towards a more quantitative understanding of few-body collision processes of alkali and helium atoms.