scholarly journals Inductive Imaging of the Concealed Defects with Radio-Frequency Atomic Magnetometers

2020 ◽  
Vol 10 (19) ◽  
pp. 6871
Author(s):  
P. Bevington ◽  
R. Gartman ◽  
W. Chalupczak
Keyword(s):  
Radio Frequency ◽  
Frequency Dependence ◽  
Phase Contrast ◽  
The Self ◽  
Frequency Range ◽  
Background Signal ◽  
Electrically Conductive ◽  
Operational Frequency ◽  
Inductive Measurement ◽  
Non Destructive

We explore the capabilities of the radio-frequency atomic magnetometers in the non-destructive detection of concealed defects. We present results from the systematic magnetic inductive measurement of various defect types in an electrically conductive object at different rf field frequencies (0.4–12 kHz) that indicate the presence of an optimum operational frequency of the sensor. The optimum in the frequency dependence of the amplitude/phase contrast for defects under a 0.5–1.5 mm conductive barrier was observed within the 1–2 kHz frequency range. The experiments are performed in the self-compensated configuration that automatically removes the background signal created by the rf field producing object response.

Mathematical model for temperature estimation forecasting of electrically conductive plate elements under action of pulsed electromagnetic radiation of radio-frequency range

2020 ◽  
Vol 8 (1) ◽  
pp. 35-42
Author(s):  
R. S. Musii ◽  
◽  
A. Y. Nakonechnyy ◽  
Keyword(s):  
Mathematical Model ◽  
Energy Dissipation ◽  
Radio Frequency ◽  
Electromagnetic Radiation ◽  
Radio Pulse ◽  
Plate Element ◽  
Frequency Range ◽  
Electrically Conductive ◽  
Conductive Plate ◽  
Pulsed Electromagnetic

A mathematical model for determining the temperature of an electrically conductive plate element under the action of pulsed electromagnetic radiation of the radio-frequency range is proposed. This model allows us to take into account the influence of the process of thermoelastic energy dissipation on the forecasting of the value of temperature in addition to the joule heat. This process is determined by thermal expansion and the action of poendromotive forces arising in the element. This approach allows us to predict a decrease in the error of temperature determination. On this basis, the distributions of temperature in an electrically conductive plate element under the action of an amplitude-modulated radio pulse have been investigated numerically. Thermoelastic energy dissipation is taken into account when using the frequencies of the carrying electromagnetic oscillations beyond the resonant frequencies and of the first resonant frequency of the electromagnetic field for this element. An estimate of the influence of the process of taking into account mechanisms of energy dissipation on the total value of temperature in the element at the specified action and used frequencies is obtained. This has allowed us to increase the accuracy of temperature measurements in this element.

scholarly journals EXTENSION OF THE FREQUENCY-RANGE OF INTERFEROMETERS FOR THE "MAGNETIC" COMPONENTS OF GRAVITATIONAL WAVES?

2007 ◽  
Vol 22 (13) ◽  
pp. 2361-2381 ◽  
Author(s):  
CHRISTIAN CORDA
Keyword(s):  
Data Analysis ◽  
Frequency Dependence ◽  
Gravitational Waves ◽  
Response Functions ◽  
Frequency Range ◽  
Total Response ◽  
High Frequencies ◽  
Magnetic Components ◽  
Linear Dimensions ◽  
Dominant Part

Recently, with an enlightening treatment, Baskaran and Grishchuk have shown the presence and importance of the so-called "magnetic" components of gravitational waves (GW's), which have to be taken into account in the context of the total response functions of interferometers for GW's propagating from arbitrary directions. In this paper the analysis of the response functions for the magnetic components is generalized in its full frequency dependence, while in the work of Baskaran and Grishchuk the response functions were computed only in the approximation of wavelength much larger than the linear dimensions of the interferometer. It is also shown that the response functions to the magnetic components grow at high frequencies, differently from the values of the response functions to the well-known ordinary components that decrease at high frequencies. Thus the magnetic components could in principle become the dominant part of the signal at high frequencies. This is important for a potential detection of the signal at high frequencies and confirms that the magnetic contributions must be taken into account in the data analysis. More, the fact that the response functions of the magnetic components grow at high frequencies shows that, in principle, the frequency-range of Earth-based interferometers could extend to frequencies over 10000 Hz.

Radio Observations of Two Large Solar Disturbances

1951 ◽  
Vol 4 (1) ◽  
pp. 51
Author(s):  
JV Hindman ◽  
AG Little ◽  
R Payne-Scott ◽  
DE Yabsley ◽  
CW Allen
Keyword(s):  
Radio Frequency ◽  
Solar Flares ◽  
Radio Frequency Power ◽  
Frequency Range ◽  
Power Flux ◽  
Apparent Position ◽  
Radio Receivers ◽  
Solar Origin ◽  
Solar Disturbances ◽  
Frequency Power

On February 17 and 21-22, 1950, two exceptionally large radio-frequency disturbances of solar origin were observed on seven radio receivers working in the frequency range from 62 to 9400 Mc/s. At each of the frequencies the radio-frequency power flux was recorded continuously during the disturbance and at several frequencies the polarization of the radiation was examined. The apparent position of the origin of the radiation was determined at one frequency. The time of commencement and the duration of the disturbances at the different frequencies were compared with each other and with those of associated phenomena, solar flares, radio fade-outs, and geomagnetic effects. The two disturbances show marked similarities and marked differences ; these are summarized.

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