Diagnostics of the condensate fraction in a clustered supersonic argon jet

TL;DR

This paper introduces a novel spectroscopic method to measure the condensate fraction and cluster density in supersonic argon jets, providing a new tool for analyzing quantum gas states in such systems.

Contribution

A new spectroscopic technique based on absolute line intensities for quantifying condensate fraction and cluster density in supersonic gases.

Findings

Determined the noncondensed atomic density in the jet.

Mapped the condensate fraction evolution across temperature range.

Validated the method with experimental data.

Abstract

A new method for determining the condensate fraction and cluster density in absolute units has been proposed and tested for a supersonic argon jet, which can also be applied to supersonic jets of other gases. The method is based on measuring the absolute intensities of the Ar II resonance lines (93.2 and 92.0 nm) when the supersonic jet is excited by an electron beam with constant current density. Knowing the absolute intensities of the lines and their emission cross sections, we determined the density of the noncondensed atomic component in the supersonic argon jet and the evolution of the condensate fraction over the whole temperature range investigated.