Uniform Field Resonators for EPR Spectroscopy: A Review. Cell Biochem Biophys 2019 Mar;77(1):3-14
Date
06/27/2018Pubmed ID
29943362Pubmed Central ID
PMC6309773DOI
10.1007/s12013-018-0845-6Scopus ID
2-s2.0-85049038251 (requires institutional sign-in at Scopus site) 7 CitationsAbstract
Cavity resonators are often used for electron paramagnetic resonance (EPR). Rectangular TE102 and cylindrical TE011 are common modes at X-band even though the field varies cosinusoidally along the Z-axis. The authors found a way to create a uniform field (UF) in these modes. A length of waveguide at cut-off was introduced for the sample region, and tailored end sections were developed that supported the microwave resonant mode. This work is reviewed here. The radio frequency (RF) magnetic field in loop-gap resonators (LGR) at X-band is uniform along the Z-axis of the sample, which is a benefit of LGR technology. The LGR is a preferred structure for EPR of small samples. At Q-band and W-band, the LGR often exhibits nonuniformity along the Z-axis. Methods to trim out this nonuniformity, which are closely related to the methods used for UF cavity resonators, are reviewed. In addition, two transmission lines that are new to EPR, dielectric tube waveguide and circular ridge waveguide, were recently used in UF cavity designs that are reviewed. A further benefit of UF resonators is that cuvettes for aqueous samples can be optimum in cross section along the full sample axis, which improves quantification in EPR spectroscopy of biological samples.
Author List
Hyde JS, Sidabras JW, Mett RRAuthors
Richard R. Mett PhD Adjunct Professor in the Biophysics department at Medical College of WisconsinJason W. Sidabras PhD Assistant Professor in the Biophysics department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
Electron Spin Resonance SpectroscopyEquipment Design
Magnetic Fields
Microwaves
