Laser cooling of a potassium-argon gas mixture using collisional redistribution of radiation

TL;DR

This paper demonstrates laser cooling of a potassium-argon gas mixture through collisional redistribution, achieving a temperature reduction of 120 K, expanding the applicability of this cooling technique to different atomic species.

Contribution

It reports the first successful laser cooling of a potassium-argon mixture, showing the technique's effectiveness with atoms having smaller fine structures.

Findings

Achieved 120 K cooling in potassium-argon mixture.

Compared cooling efficiency with rubidium-argon, noting differences.

Validated collisional redistribution as a versatile cooling method.

Abstract

We study laser cooling of atomic gases by collisional redistribution, a technique applicable to ultradense atomic ensembles at a pressure of a few hundred bar. Frequent collisions of an optically active atom with a buffer gas shift atoms into resonance with a far red detuned laser beam, while spontaneous decay occurs close to the unperturbed resonance frequency. In such an excitation cycle, a kinetic energy of the order of the thermal energy kT is extracted from the sample. Here we report of recent experiments investigating the cooling of a potassium-argon gas mixture, which compared to an rubidium-argon mixture investigated in earlier experiments has a smaller fine structure of the optically active alkali atom. We observe a relative cooling of the potassium-argon gas mixture by 120 K.