| 摘要 |
The invention relates to a system and a method for magnetic imaging. The imaging field Bo and the pre- polarisation field Bp are produced by means of electromagnets ALC in the air gap situated between its pole shoes IPP. The pole shoes IPP are designed so that when the current of the electromagnet is increased, the strength of the magnetic field between the central part of the pole shoes increases only to the pre-polarisation field strength Bp. This is due to the fact that the measurement of the magnetic field at the edge areas of the pole shoes defines the increase in the field strength at the edge areas of the air gap. <IMAGE>
|
