Superconducting Induction Magnetometer

摘要

An attempt to generalize the current knowledge of passive magnetic field transducers-- SQUID and induction sensors (ISs) (MAFCOPS)--and to incorporate elements of both designs in order to find a way to improve their performance data (PD) by creating, in theory, a combined transducer-- superconducting induction magnetometer (SIM). State-of-the-art IS design is shown with two modifications for applications in outer space--LF with sensitivity threshold (ST) 5 pT/(Hz)~(1/2) / 5 fT/(Hz)~(1/2) in frequency range (FR) 20 Hz/16 kHz and HF with ST 0.5 pT/Hz~(1/2)/1 fT/(Hz)~(1/2) in FR 10 kHz / 10 MHz. The superconducting field-effect transistor (SuFET) is incorporated into a wide-band IS device in order to acquire an ST below 1 fT/(Hz)~(1/2) in the FR from small values of Hertz to tens of megahertz (0.1 / 10~(7) Hz). The proposed magnetometer circuit consists of both a room-temperature or cooled (up to superconductive) pickup coil (PC) and a SuFET. Both the transfer function and the ST for SIM are analytically investigated proceeding from the equivalent and noise circuit, respectively. The sensitivity improvement of some SIM variants is shown in comparison with other state-of-the-art MAFCOPS. Constructional and operational distinctions of the designed sensor are explained.