Patent attributes
An apparatus and method for dynamically stabilizing the fields in a permanent magnet assembly, including a nuclear magnetic resonance machine. One or more magnetically active elements affect the fields of the magnet assembly. A mechanism controls and changes the position(s) of the magnetically active element(s) to affect and adjust the magnetic field strength in the working volume of the assembly. A sensor provides a control signal indicating the status of the magnetic field strength, and an algorithm is executed for determining, based on the signal, the manner in which the adjustment should be made. The adjustment may be continuous and dynamic, and stabilization of the field may occur during operation of the permanent magnet assembly. The adjustments of the position of the magnetically active element stabilize the field without unduly degrading the field homogeneity, even for high homogeneity magnets.