Devices, systems, and methods for testing samples in temporally modulated magnetic fields

The system of 1, wherein the magnetic field generator comprises:

• a frame, which is rotatable about a rotational axis intersecting the frame from a frame back side to a frame front side;
• a motor configured to rotate the frame at a controllable angular velocity;
• and
• a magnet unit, which comprises one or more permanent magnets, is mounted on the frame front side at a location offset by a distance r0 relative to the rotational axis, and forms in front of the magnet unit a first magnetic field;
• wherein, when the frame is rotated, in front thereof, at any azimuth and offset relative to the rotational axis by the distance r0, a respective temporally modulated second magnetic field, is generated.

A method for magnetic testing of samples, the method comprising:

• a setup stage comprising providing a sample to be tested and a magnetic field generator configured to produce a temporally modulated magnetic field by rotating at least one magnet, which is permanent;
• a data acquisition stage comprising for each of a plurality of temporal modulation amplitudes of the magnetic field and/or frequencies of the EM signals:
• producing the magnetic field whereat the sample is positioned;
• transmitting an EM signal into a waveguide positioned adjacently to the sample;
• obtaining a measured signal by measuring a power of a transmitted portion of the EM signal over a time interval spanning multiple rotation cycles of the at least one magnet;
• and
• a data processing stage comprising:
• demodulating each of the measured signals using a respective reference signal indicative of the modulation rate of the respective magnetic field;
• and
• processing the demodulated signals to obtain one or more sample parameters parameterizing one or more properties of the sample.