title: Optimization of axial RF field distribution in low-frequency EPR loop-gap resonators.
abstract: A novel coupling method that optimizes the axial RF distribution of low-frequency EPR loop-gap resonators is presented. It consists of a resonant coupling loop positioned at the centre of a two-section loop-gap resonator. This arrangement ensures a symmetrical distribution of the radio frequency field along the axis of the resonator. The design of a central coupling system suitable for EPR resonators operating at about 220 MHz is described. Experimental results show that with the central coupling system the RF field is symmetrical and has a very good axial homogeneity (100% of the resonator length).
authors.affiliation: INFM and Dipartimento di Scienze e Tecnologie Biomediche, Università dell'Aquila, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Diodato
authors.forename: M
authors.initials: M
authors.lastname: Alecci
authors.forename: J A
authors.initials: JA
authors.lastname: Brivati
authors.forename: V
authors.initials: V
authors.lastname: Varoli
authors.forename: A
authors.initials: A
authors.lastname: Sotgiu
mesh_terms: D055592:Biophysical Phenomena; D001703:Biophysics; D004578:Electron Spin Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D004582:Electronics, Medical / Q000295:instrumentation; D004867:Equipment Design; D005069:Evaluation Studies as Topic; D011846:Radio Waves