A New Design of Resonant Cavity for the W-band EPR spectrometer

TL;DR

This paper introduces a novel resonant cavity design for W-band EPR spectrometers that is adaptable to different magnet types and supports both CW and pulsed experiments, enhancing versatility in various scientific fields.

Contribution

The paper presents a new cavity design compatible with solenoid and split-pair magnets, featuring adjustable coupling for diverse EPR experiments.

Findings

Successful demonstration of coupling adjustment via reflection coefficient measurement.

Effective operation in both CW and pulsed EPR modes.

Potential for broad application in physics, chemistry, and biology.

Abstract

We report a new design of resonant cavity for W-band EPR spectrometer. It suits with both solenoid-type and split-pair magnets. The cavity operates on the TE$_{011}$ mode, where the microwave magnetic field is along the cylindrical axis. Its cylindrical axis is horizontal, so the magnetic field of the microwave is always perpendicular to the vertical external magnetic field provided by a solenoid-type magnet. By rotating the cavity, the microwave magnetic field can also be perpendicular to a horizontal external field when a split-pair magnet is used. Furthermore, a tiny metal cylinder allows for the adjustment of coupling. This enables both continuous-wave (CW) and pulsed EPR experiments. The coupling-varying ability has been demonstrated by reflection coefficient (S11) measurement, and CW and pulsed EPR experiments have been conducted. The performance data indicates a prospect of wide applications of the cavity in the fields of physics, chemistry and biology.