Understanding the working of a B-dot probe

TL;DR

This paper investigates the transient response of B-dot probes, addressing electrical oscillations, and demonstrates methods to improve measurement accuracy of time-varying magnetic fields.

Contribution

It provides a detailed analysis of B-dot probe oscillations and introduces techniques to remove them, ensuring more accurate magnetic field measurements.

Findings

Oscillations in B-dot probes can be effectively removed.

Time-integrated emf is linearly proportional to the magnetic field.

Improved measurement fidelity of time-varying magnetic fields.

Abstract

Magnetic pickup loops or B-dot probes are one of the oldest known sensors of time-varying magnetic fields. The operating principle is based on Faraday's law of electromagnetic induction. However, obtaining accurate measurements of time-varying magnetic fields using these kinds of probes is a challenging task. A B-dot probe and its associated circuit are prone to electrical oscillations. As a result, the measured signal may not faithfully represent the magnetic field sampled by the B-dot probe. In this paper, we have studied the transient response of a B-dot probe and its associated circuit to a time-varying magnetic field. Methods of removing the oscillations pertaining to the detector structure are described. After removing the source of the oscillatory signal, we have shown that the time-integrated induced emf measured by the digitiser is linearly proportional to the magnetic field sampled by the B-dot probe, thus verifying the faithfulness of the measured signal.