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A radio-frequency coil for the experimental investigation of the magnetic properties of thin superconducting films under microwave fields at different values of temperature and dc magnetic field has been developed. The system has been used for low-temperature microwave frequency-dependent magnetization measurements in a Pb thin film with an engineered periodical antidot array. The characteristic frequencies and the electric and magnetic fields of the resonant system formed by a multi-turn coil with a sample loaded in its core are estimated using the helical approach. A good agreement of the calculated values with those recorded in swept-frequency spectra is obtained. The relation between the characteristics of the resonant structure and the frequency-driven magnetic response of the sample at different nominal microwave powers documents the capability and sensitivity of the layout.
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http://dx.doi.org/10.1063/1.4921710 | DOI Listing |
Solid State Nucl Magn Reson
October 2025
CSIRO, Lucas Heights Science and Technology Centre, Lucas Heights, 2234, NSW, Australia.
The ability to rapidly detect the presence of narcotic substances in baggage and on personnel is a prime requirement in airports, mail distribution centres and mass screening portals. Nuclear Quadrupole Resonance (NQR) is well-suited to detect selected narcotics as the resonances can be highly discriminating of a given substance due to the presence of narrow, non-overlapping spectral lines. Furthermore, the transparency of non-conductive materials to radio frequency (RF) magnetic fields allows for NQR to measure bulk volumes without any sample preparation.
View Article and Find Full Text PDFRev Sci Instrum
August 2025
University of South China, Hengyang 421001,China.
High-power efficient coupling and high-density negative ion beam extraction are critical challenges urgently requiring solutions for the Radio Frequency (RF) driven Negative ion based Neutral Beam Injection (NNBI) systems. To improve the power transfer efficiency of the RF ion source power supply and simultaneously simplify the design of the NNBI filter magnetic field, this paper proposes a novel discharge control method for NNBI RF ion sources. The design scheme of the RF ion source inverter power supply is analyzed.
View Article and Find Full Text PDFNat Commun
August 2025
Kavli Institute of Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, Oxford, UK.
NMR experiments require sequences of radio frequency (RF) pulses to manipulate nuclear spins. Signal is lost due to non-uniform excitation of nuclear spins resonating at different energies (chemical shifts) and inhomogeneity in the RF unavoidably generated by hardware over the sample volume. To overcome this, we present Seedless, a tool to calculate NMR pulses that compensate for these effects to enhance control of magnetisation and boost signal.
View Article and Find Full Text PDFHardwareX
September 2025
CIIDIR Unidad Oaxaca, Instituto Politécnico Nacional, Calle Hornos No. 1003, Col. Noche Buena, Santa Cruz Xoxocotlán, Oaxaca 71230, Mexico.
This paper presents the design and construction of a cost-effective embeddable nuclear magnetic resonance sensor using 3D printing to improve the construction process. The sensor comprises two 25.4 mm diameter x 3 mm thick neodymium-iron-boron disk magnets and an elliptical radio frequency coil.
View Article and Find Full Text PDFBioengineering (Basel)
May 2025
Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK.
The acquisition of electroencephalography (EEG) concurrently with functional magnetic resonance imaging (fMRI) requires a careful consideration of the health hazards resulting from interactions between the scanner's electromagnetic fields and EEG recording equipment. The primary safety concern is excessive RF-induced heating of the tissue in the vicinity of electrodes. We have previously demonstrated that concurrent intracranial EEG (icEEG) and fMRI data acquisitions (icEEG-fMRI) can be performed with acceptable risk in specific conditions using a head RF transmit coil.
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