An Electromagnetic Induction System for Observation of Bulk Magnetization Response of UXO Targets
Abstract
The root of this problem is that the primary field transmitter and the secondary receiver in an EM system are both in vicinity of one another where primary implies the magnetic field produced by a transmitter coil, while secondary implies the magnetic field produced by a target, in response to the primary field. It is common knowledge that the primary field, in the vicinity of the receiver coil, is orders of magnitude larger than the secondary field at the receiver. To observe the secondary field, the primary field must be removed from the observation. This problem is circumvented in time domain EM systems by turning off the primary field and then observing the secondary field that persists after turn-off. The secondary field in this case is the eddy current response of the target. However, a target also has a bulk magnetic response and that response can only be observed while the primary field is present. The eddy current response is driven by changes in the primary field (dB/dt). The bulk magnetic response is driven directly by the primary field1. The bulkmagnetic response is exactly same shape as the primary and is present only while the primary is present.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 2012
- Accession Number
- ADA578935
Entities
People
- David George
- Thomas Bell