| Popis: |
Describes a device for measurement, control and mapping of magnetic fields. The magnetic sources, mainly coils, are powered by an alternating current; a pick-up coil detects the induced EMF, which is amplified by a phase-sensitive detector. Operating at low frequencies (below 100 Hz) substantially reduces the eddy current effects when conducting materials are near the coils. An application to control the linearity of a magnetic gradient is indicated. The simplicity of this device makes it very efficient in the design of gradient coil systems for nuclear magnetic resonance imaging. |
