Temperature-dependent radiative lifetime measurement of the $6^1\Sigma_g^+(v=9,J=31)$ state of sodium molecules

TL;DR

This study measures how the radiative lifetime of a specific sodium molecule state varies with temperature, using high-resolution spectroscopy and comparing results with theoretical predictions.

Contribution

It provides the first experimental data on the temperature dependence of the radiative lifetime for the $6^1\Sigma_g^+(v=9,J=31)$ state of sodium molecules.

Findings

Radiative lifetimes measured at different temperatures show good agreement with theoretical calculations.

The lifetime decreases with increasing temperature within the studied range.

The method used allows accurate extrapolation to zero buffer gas pressure.

Abstract

We report the measurement of radiative lifetimes of the $6^1\Sigma_g^+(v=9,J=31)$ state of gas-phase molecular sodium using a high-resolution double-resonance spectroscopy. Measurements were done using a time-correlated photon counting technique at various pressures and temperatures. Lifetimes were extracted from extrapolations to the zero buffer gas pressure, called Stern-Volmer plot, and the temperature-dependence of the radiative lifetimes were measured over a temperature range from 593 K to 653 K. Our result agrees well within the error limits with the theoretical calculations.