Measurment of the molar polarizability of argon

Purpose and goal

The purpose of this project is to investigate, through an innovative new method, the possibility of using an Fabry-Perot (FP) refractometer with ultra-high precision/resolution to measure the molar polarizability (Ar) of Argon. Should the methodology work as intended, it will also be able to be used to measure cavity deformation in FP refractometers, which would mean that the polarizability of different gases can be measured. This is important and relevant for several different applications in metrology.

Expected effects and result

The project will contribute to Sweden continuing to be at the forefront of the development of Fabry-Pérot refractometers. An improvement in the molar polarization of argon is the ultimate goal (which would indirectly lead to better pressure measurements). Today, there are very few quality-assured saturation measurements of the molar polarization, which means that new measurements are extremely relevant. This project will also further strengthen Sweden´s position within new quantum-based realizations of SI units, which is indisputably a future field for metrology.

Planned approach and implementation

The project is divided into three parts. In the first part, the proposed method will be demonstrated through preliminary measurements in our existing system. In the second part, a partially new system will be constructed to improve the possibilities of measuring with very high accuracy. Finally, the project ends with measurements of Argon´s molar polarizability and dissemination of these results through an article.