A 263 GHz continuous-wave (CW) gyrotron was developed at the IAP RAS for future applications as a microwave power source in Dynamic Nuclear Polarization / Nuclear magnetic resonance (DNP/NMR) spectrometers. A new experimental facility with a computerized control was built to test this and subsequent gyrotrons. We obtained the maximum CW power up to 1 kW in the 15 kV/0.4 A operation regime. The power about 10 W, which is sufficient for many spectroscopic applications, was realized in the low current 14 kV/0.02 A regime. The possibility of frequency tuning by variation of the coolant temperature about 4 MHz/1 °C was demonstrated. The spectral width of the gyrotron radiation was about 10(-6).
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http://dx.doi.org/10.1063/1.4921322 | DOI Listing |
IEEE Trans Electron Devices
November 2023
Department of Electrical and Computer Engineering, University of California, Davis, CA 95616, U.S.A.
In this letter, a 263 GHz traveling wave tube for electron paramagnetic resonance spectroscopy is designed, fabricated and tested. A periodic permanent magnet focused pencil beam electron optical system is adopted. A folded waveguide slow-wave structure with modified serpentine bends is optimized to provide high-power wideband performance and stable operation.
View Article and Find Full Text PDFWith the development of photonic integration technology, meta-waveguides have become a new research hotspot. They have broken through the theoretical diffraction limit by virtue of the strong electromagnetic manipulation ability of the metasurface and the strong electromagnetic field limitation and guidance ability of the waveguide. However, the reported meta-waveguides lack research on dynamic modulation.
View Article and Find Full Text PDFSci Rep
August 2023
Department of Electronics and Communication, Nagarjuna College of Engineering and Technology, Bengaluru, Karnataka, India.
In this communication, a planar dual port multiple input multiple output antenna of size 1.2λ × 0.6λ × 0.
View Article and Find Full Text PDFPhys Chem Chem Phys
September 2023
N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, 9 Pr. Ak. Lavrentjeva, Novosibirsk 630090, Russia.
The combination of fluorine labeling and pulsed electron-nuclear double resonance (ENDOR) is emerging as a powerful technique for obtaining structural information about proteins and nucleic acids. In this work, we explored the capability of Mims F ENDOR experiments on reporting intermolecular distances in trityl- and F-labeled DNA duplexes at three electron paramagnetic resonance (EPR) frequencies (34, 94, and 263 GHz). For spin labeling, we used the hydrophobic Finland trityl radical and hydrophilic OX063 trityl radical.
View Article and Find Full Text PDFJ Magn Reson
August 2023
Department of Statistical Science, University College London, WC1E 6BT, United Kingdom. Electronic address:
ENDOR spectroscopy is a fundamental method to detect nuclear spins in the vicinity of paramagnetic centers and their mutual hyperfine interaction. Recently, site-selective introduction of F as nuclear labels has been proposed as a tool for ENDOR-based distance determination in biomolecules, complementing pulsed dipolar spectroscopy in the range of angstrom to nanometer. Nevertheless, one main challenge of ENDOR still consists of its spectral analysis, which is aggravated by a large parameter space and broad resonances from hyperfine interactions.
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