# Viscosity measurements in pulsed magnetic fields by using a quartz-crystal microbalance

## TL;DR

This paper introduces a method to measure liquid viscosity in pulsed magnetic fields using a quartz-crystal microbalance, enabling high-resolution, simultaneous measurements of frequency and quality factor during magnetic pulses.

## Contribution

The study develops a novel technique combining QCM with pulsed magnetic fields to measure viscosity with high resolution and demonstrates its effectiveness with liquid oxygen.

## Key findings

- Viscosity can be accurately measured up to 55 T.
- Resonant frequency and Q factor change with $(
ho ext{eta})^{0.5}$.
- Resolution of viscosity measurement is approximately 0.5%.

## Abstract

Viscosity measurements in combination with pulsed magnetic fields are developed by use of a quartz-crystal microbalance (QCM). When the QCM is immersed in liquid, the resonant frequency, $f_0$, and the quality factor, $Q$, of the QCM change depending on $(\rho\eta)^{0.5}$, where $\rho$ is the mass density and $\eta$ the viscosity. During the magnetic-field pulse, $f_0$ and $Q$ of the QCM are simultaneously measured by a ringdown technique. The typical resolution of $(\rho\eta)^{0.5}$ is 0.5 %. As a benchmark, the viscosity of liquid oxygen is measured up to 55 T.