Magnetomodulating Magnetometer Based on High-Temperature Superconductors

• Published in: IEEE magnetics letters Vol. 10; pp. 1 - 5
• Main Authors: Ichkitidze, Levan P., Belodedov, Mikhail V., Selishchev, Sergey V., Telyshev, Dmitry V.
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 2019; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Artificial organs; Biomagnetics; Biomedical materials; Bismuth strontium calcium copper oxide; Coils; Diameters; Excitation; Harmonic analysis; Harmonic response; High temperature superconductors; high-temperature superconducting ceramics; Magnetic field measurement; magnetic field sensor; Magnetic fields; Magnetic flux; magnetic instruments; Magnetic measurement; Magnetometers; magnetomodulation; magnetosensitivity; noninvasive detection; Selectivity; Sensitivity; Sensors; SQUIDs; Superconducting magnets
• ISSN: 1949-307X; 1949-3088
• DOI: 10.1109/LMAG.2019.2957250

A magnetomodulation magnetic field sensor (MM-MFS) based on a high-temperature superconducting (HTSC) ceramic material in the Bi-2223 system was investigated. A cylindrical HTSC ceramic rod with a length of 10 mm and a diameter of 2 mm was used as a magnetically sensitive element. The MM-MFS operates in a differential mode, which automatically eliminates the effect of odd harmonics in the signal coil. The second harmonic response signal and magnetosensitivity of the sensor depend linearly on the frequency of the excitation field. The parameters of the sensor were experimentally determined, including a magnetosensitivity of about 500 V/T, a threshold sensitivity of about 20 pT, a magnetic field measurement range of approximately ±0.7 mT, and a dynamic measurement range of about 120 dB in the area ±15 μT. According to the estimates, the optimal choice of number of turns, selectivity, and identity of two parts of the excitation coil can significantly reduce the MM-MFS threshold sensitivity to below 1 pT. The MFS-MM can compete with HTSC SQUIDs in biomedical applications for noninvasive detection of magnetic particles and in various implantable devices and artificial organs.