title: Dielectric-Backed Aperture Resonators for X-Band in vivo EPR Nail Dosimetry.
abstract: A new resonator for X-band in vivo EPR nail dosimetry, the dielectric-backed aperture resonator (DAR), is developed based on rectangular TE102geometry. This novel geometry for surface spectroscopy improves at least a factor of 20 compared to a traditional non-backed aperture resonator. Such an increase in EPR sensitivity is achieved by using a non-resonant dielectric slab, placed on the aperture inside the cavity. The dielectric slab provides an increased magnetic field at the aperture and sample, while minimizing sensitive aperture resonance conditions. This work also introduces a DAR semi-spherical (SS)-TE011geometry. The SS-TE011geometry is attractive due to having twice the incident magnetic field at the aperture for a fixed input power. It has been shown that DAR provides sufficient sensitivity to make biologically relevant measurements both in vitro and in vivo Although in vivo tests have shown some effects of physiological motions that suggest the necessity of a more robust finger holder, equivalent dosimetry sensitivity of approximately 1.4 Gy has been demonstrated.
authors.affiliation: Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA.
authors.forename: Oleg
authors.initials: O
authors.lastname: Grinberg
authors.affiliation: Department of Biophysics, Medical College of Wisconsin, Milwaukee, WI 53211, USA.
authors.forename: Jason W
authors.initials: JW
authors.lastname: Sidabras
authors.affiliation: Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA.
authors.forename: Dmitriy S
authors.initials: DS
authors.lastname: Tipikin
authors.affiliation: Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Krymov
authors.affiliation: Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Mariani
authors.affiliation: Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA.
authors.forename: Matthew M
authors.initials: MM
authors.lastname: Feldman
authors.affiliation: Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA.
authors.forename: Maciej M
authors.initials: MM
authors.lastname: Kmiec
authors.affiliation: Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA.
authors.forename: Sergey V
authors.initials: SV
authors.lastname: Petryakov
authors.affiliation: Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA.
authors.forename: Spencer
authors.initials: S
authors.lastname: Brugger
authors.affiliation: Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA.
authors.forename: Brandon
authors.initials: B
authors.lastname: Carr
authors.affiliation: Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA.
authors.forename: Wilson
authors.initials: W
authors.lastname: Schreiber
authors.affiliation: Department of Radiation Oncology, University of Florida, Gainesville, FL 32610, USA.
authors.forename: Steven G
authors.initials: SG
authors.lastname: Swarts
authors.affiliation: Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA Harold.M.Swartz@dartmouth.edu.
authors.forename: Harold M
authors.initials: HM
authors.lastname: Swartz
mesh_terms: D001681:Biological Assay / Q000295:instrumentation*; D017097:Electric Impedance; D004578:Electron Spin Resonance Spectroscopy / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D008872:Microwaves; D009262:Nails / Q000737:chemistry* / Q000528:radiation effects*; D011874:Radiometry / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014159:Transducers