scholarly journals Validation of numerical methods for electromagnetic dosimetry through near-field measurements

ACTA IMEKO ◽  
2015 ◽  
Vol 4 (1) ◽  
pp. 90 ◽  
Author(s):  
Domenico Giordano ◽  
Luca Zilberti ◽  
Michele Borsero ◽  
Roberto Forastiere ◽  
Wencui Wang
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Field ◽  
Electromagnetic Field ◽  
Boundary Element Method ◽  
Near Field ◽  
Larmor Frequency ◽  
Field Measurements ◽  
Magnetic Element ◽  
Resonance Imaging ◽  
Set Up

This paper describes the arrangement of a first experimental set-up which allows the comparison between the measurement of the electromagnetic field quantities induced inside a simple cylindrical phantom and the same quantities estimated numerically through a boundary element method. The reliability of the numerical method has been tested at 64 MHz, the Larmor frequency associated to the magnetic resonance imaging devices with an isocenter magnetic field of 1.5 T. To assess its robustness, the comparison is also performed by introducing, inside the phantom, a metallic non magnetic element, which roughly simulates a medical implant.

Far field modeling of the Mamala Bay outfalls

1998 ◽  
Vol 38 (10) ◽  
pp. 323-330
Author(s):  
Philip J. W. Roberts
Keyword(s):  
Field Model ◽  
Near Field ◽  
Far Field ◽  
Field Modeling ◽  
Visitation Frequency ◽  
Statistical Variation ◽  
Long Time ◽  
Harmonic Average ◽  
Ocean Outfall ◽  
Acoustic Doppler Current Profilers

The results of far field modeling of the wastefield formed by the Sand Island, Honolulu, ocean outfall are presented. A far field model, FRFIELD, was coupled to a near field model, NRFIELD. The input data for the models were long time series of oceanographic observations over the whole water column including currents measured by Acoustic Doppler Current Profilers and density stratification measured by thermistor strings. Thousands of simulations were made to predict the statistical variation of wastefield properties around the diffuser. It was shown that the visitation frequency of the wastefield decreases rapidly with distance from the diffuser. The spatial variation of minimum and harmonic average dilutions was also predicted. Average dilution increases rapidly with distance. It is concluded that any impact of the discharge will be confined to a relatively small area around the diffuser and beach impacts are not likely to be significant.

scholarly journals Efficient Planar Near-field Measurements for Radiation Pattern Evaluation by a Warping Strategy

IEEE Access ◽  
2021 ◽  
pp. 1-1
Author(s):  
Maria Antonia Maisto ◽  
Giovanni Leone ◽  
Adriana Brancaccio ◽  
Raffaele Solimene
Keyword(s):  
Radiation Pattern ◽  
Near Field ◽  
Field Measurements

Atomic 2D electric field imaging of a Yagi–Uda antenna near-field using a portable Rydberg-atom probe and measurement instrument

2020 ◽  
Vol 9 (5) ◽  
pp. 305-312
Author(s):  
Ryan Cardman ◽  
Luís F. Gonçalves ◽  
Rachel E. Sapiro ◽  
Georg Raithel ◽  
David A. Anderson
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Field Measurement ◽  
Near Field ◽  
Measurement Instrument ◽  
Rydberg Atom ◽  
Field Measurements ◽  
Atom Probe ◽  
Electric Field Measurement ◽  
Measurement Uncertainties

AbstractWe present electric field measurements and imaging of a Yagi–Uda antenna near-field using a Rydberg atom–based radio frequency electric field measurement instrument. The instrument uses electromagnetically induced transparency with Rydberg states of cesium atoms in a room-temperature vapor and off-resonant RF-field–induced Rydberg-level shifts for optical SI-traceable measurements of RF electric fields over a wide amplitude and frequency range. The electric field along the antenna boresight is measured using the atomic probe at a spatial resolution of ${\lambda }_{RF}/2$ with electric field measurement uncertainties below 5.5%, an improvement to RF measurement uncertainties provided by existing antenna standards.

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