Dielectric permittivity of deeply supercooled water according to the measurement data at the frequencies 7.6 GHz and 9.7 GHz

TL;DR

This study measures the dielectric permittivity of supercooled water at GHz frequencies, updating the Debye model to accurately describe its temperature dependence from -20°C to -60°C.

Contribution

It provides new measurement data and refined formulae for dielectric permittivity of supercooled water applicable across a broad GHz frequency range.

Findings

Updated temperature dependence of relaxation frequencies.

Refined dielectric permittivity formulae for supercooled water.

Applicability of the model from 7 to 200 GHz.

Abstract

Dielectric permittivity of supercooled volume water has been measured in the range of temperatures from $-20\,^{\circ}$C to $-60\,^{\circ}$C at the frequencies $7.6$~GHz and $9.7$~GHz. The measurements have been made using microwave resonators and wetted silicate sorbents. From the data obtained, the temperature dependences of the relaxation frequencies were updated for the Debye model with two relaxation frequencies. The updated formulae for dielectric permittivity of cold water may be applied to the frequency range $7\ldots200$~GHz.