Calibration of the open-flat coil-based tunnel diode oscillator technique (OFC magnetometer) for quantitative extraction of physical characteristics of superconductive state

Newly-Proposed Methods for Early Detection of Incoming Earthquakes, Tsunamis & Tidal Motion

“…Besides, due to flat shape, even a little shift of the position of a normal-conducting plate, placed near the coil, may www.intechopen.com lead to strong distortion of the field distribution around the coil. These features, and the stability of TD-oscillators (F stability 1-10Hz, F/F10  7 -10  6  depending on the model & temperature  see [2,[11][12]) enabled us to reach 6 orders relative resolution in SFCO technique [3][4], permitting to effectively use it in a basic research [5][6][7][8], as well as in some modern technical applications [9][10]. In the last case, frequency of the oscillator is mainly used as a testing parameter, and the measuring effect is determined by a distortion of the MHz-range testing field configuration near the coil face by the vibrating copper plate, leading to the magnetic inductance changes of the coil, with a resolution  1-10pH (depending on operation temperature of a technique), resulting in the changes of test oscillator frequency.…”

“…Below, we discuss work-principle, and test data of such a new position sensor, installed in a known Russian SM-3 seismometer (for validation) as an additional pick-up element -showing its advantages compared to traditional techniques. We also discuss potentials of this novel absolute-position sensor, operating down to liquid- 4 He temperatures, and in high magnetic fields -as a real-time measurement element for early detection of earthquakes, incoming tsunamis, tidal motion, and for tracking borders. We discuss also possible design of seismic detectors based on this sensor.…”

“…It can be used for determination of too much little changes of distances with d~1-10Å absolute and d/d~10  5 -10  6 relative resolution (depending on a model and working temperature of the TD-oscillator [3][4]. It is also a sensitive radio-frequency (RF) Q-meter  to study absorption as small as 10  9 W in thin flat materials (for example, in plate-like high-T c superconductors [5][6][7]).…”

“…It is also a sensitive radio-frequency (RF) Q-meter  to study absorption as small as 10  9 W in thin flat materials (for example, in plate-like high-T c superconductors [5][6][7]). The SFCO method can operate down to the liquid 4 He temperatures. Presently, it is tested by us up to 12T magnetic fields [7].…”

“…ment of the resolution of measurements by 3-4 orders of magnitude (especially, in studies of thin, plate-like HTS materials [1,[3][4][5][6][7][8]). For comparison, typical values of the filling factor for solenoid coils are 10  4 10  3 for the said samples.…”