Apparatus and method of measuring the multi-dimensional magnetic field distribution of a magnetic sample in real-time

An apparatus for determining the magnetic field distribution of a magnetic sample, the apparatus comprising:

• magnetic field sensing means for sensing the magnetic field produced by the sample at a given location, said magnetic field sensing means comprising a sensing head having a plurality of magnetic sensors arranged to sense magnetic field strength in plural orthogonal directions;
• scanning means arranged to effect area scanning of said magnetic sample by movement of said sensing head relative to the sample along a predetermined scan pattern, said scanning means making sub-millimeter positional movements of said sensing head and thus achieving a correspondingly high resolution of the magnetic field distribution determined by the apparatus;
• data acquisition means coupled to said magnetic field sensing means and to said scanning means, said data acquisition means-being dedicated to the processing of signals outputted by said sensors and to the control of said scanning means and comprising analog-to-digital signal conversion means coupled to said sensors for converting the analog outputs thereof into corresponding digital signals;
• storage means for storing said digital signals;
• a microprocessor controlling the operation of said analog-to-digital signal conversion means and the storage of said digital signals in said storage means, said microprocessor additionally controlling the operation of said scanning means in coordination with said analog-to-digital signal conversion means and said storage means;
• and
• computer means including display means, said computer means being arranged to receive digital data from the storage means of said data acquisition means under control of said microprocessor, to process said digital data into user understandable magnetic field maps, and to display said magnetic field maps upon said display means,
• wherein the scanning means comprises a robot assembly to which said sensing means is coupled, said robot assembly including first means for moving said sensing means in one coordinate dimension, and second means for effecting relative rotation between the sample and the sensing means.