Radio-frequency atomic magnetometer for defect detection and object surveillance
In person: 30 September 2021 • 2:40 PM - 3:00 PM BST | Lomond Auditorium
Instruments based on radio-frequency inductive technologies (Magnetic Induction Tomography) create an exciting alternative to standard defect detection and object surveillance methods. The rf atomic magnetometer brings superior sensitivity to inductive measurements, in addition to a range of functionalities. The inductive response of an object to an oscillating magnetic field reveals information about its electrical conductivity and magnetic permeability. We demonstrate that it is possible to determine material composition by measuring the angular, frequency, and spatial dependence of the inductive response. Identification is performed by referencing the object's response to that from materials with mutually exclusive properties such as copper (high electric conductivity, negligible magnetic permeability) and ferrite (opposite). This technique uses the difference in object response generated by eddy currents and magnetisation. Possible applications are in security screening devices.
National Physical Lab. (United Kingdom)
Patrick Bevington recently completed his PhD studying radio-frequency atomic magnetometers and their application for a non-destructive imaging technique called magnetic induction tomography. He has stayed on at the national physical laboratory to further these investigations and work on building a practical sensor.