Practical Doppler broadening thermometry

TL;DR

This paper explores the development of a compact, calibration-free thermometer based on Doppler broadening thermometry (DBT) using alkali metal vapors, aiming for reliable long-term temperature measurements in challenging environments.

Contribution

It presents initial proof-of-concept research for a primary, calibration-free DBT sensor utilizing alkali metal vapors for long-term thermometry applications.

Findings

Demonstrated initial feasibility of DBT with alkali vapors

Achieved stable spectral line measurements for temperature estimation

Identified potential for in-situ long-term thermometry in nuclear environments

Abstract

We report initial research to develop a compact and practical primary thermometer based on Doppler broadening thermometry (DBT). The DBT sensor uses an intrinsic property of thermalized atoms, namely, the Doppler width of a spectral line characteristic of the atoms being probed. The DBT sensor, being founded on a primary thermometry approach, requires no calibration or reference, and so in principle could achieve reliable long-term in-situ thermodynamic temperature measurement. Here we describe our approach and report on initial proof-of-concept investigations with alkali metal vapour cells. Our focus is to develop long-term stable thermometers based on DBT that can be used to reliably measure temperatures for long periods and in environments where sensor retrieval for re-calibration is impractical such as in nuclear waste storage facilities.