On the geometry optimization of X-band resonator for electron paramagnetic resonance application

TL;DR

This paper presents a detailed computer model for optimizing the geometry of an X-band resonator used in Electron Paramagnetic Resonance, significantly enhancing its sensitivity by tenfold compared to the original design.

Contribution

A comprehensive electromagnetic model of the EPR resonator was developed, enabling geometric optimization for maximum sensitivity improvement.

Findings

Optimized resonator has 10 times greater sensitivity.

Detailed electromagnetic model includes all physical components.

Resonator geometry significantly influences Q-factor and frequency.

Abstract

The microwave resonator is one of the key components in the modern Electron Paramagnetic Resonance (EPR) spectroscopy setup, as it largely determines the performance characteristics and limitations of the entire spectrometer. In this research note the possible way of resonator optimization is described. A detailed computer model describing the distribution of the electromagnetic field for Bruker 4118X-MD-5W1 design resonator has been developed. All details including a dielectric insert, conductive screen, coupling antenna and PTFE supports were included in the model. All dissipation processes were considered in the calculation. The influence of the resonator geometry on the Q-factor, filling factor and operating frequency of the resonant mode has been investigated. The resonator geometric parameters are optimized to achieve maximum sensitivity. According to the calculations, the optimized resonator structure has in 10 times greater sensitivity than the original MD-5 design.