Method for fabricating an electromagnetic actuator, an electromagnetic actuator, and a charged particle device comprising the same

摘要

The present invention is related to a method for fabricating an electromagnetic actuator. It is further related to an electromagnetic actuator and a charged particle device comprising such an actuator. According to the present invention, the method for fabricating is characterized by determining an optimal allocation of permanent magnets to reduce the magnetic stray field caused by deviations between the nominal and actual magnetization values of the permanent magnets. The invention further provides a charged particle device comprising an electromagnetic actuator fabricated using the method according to the invention.

主权项

1. A method for fabricating an electromagnetic actuator, comprising:
providing a plurality of permanent magnets each having a nominal magnetization value which is subjected to tolerance; providing a first frame part having an electric coil; providing an electrical supply for driving the electric coil; providing a second frame part having a plurality of predefined receiving positions for receiving the plurality of permanent magnets; arranging the plurality of permanent magnets at the plurality of receiving positions for obtaining a magnetic arrangement having an alternating pole pattern in a first direction; coupling the first and second frame part;wherein the first and second frame part are arranged to allow relative movement between them along the first direction as a result of driving the electric coil; characterized by
computing a correlation between an allocation of each of the plurality of permanent magnets to the plurality of receiving positions and the magnetic field at a first predefined interference point; optimizing the allocation with respect to a predetermined maximum value of the magnetic field at the first interference point using the correlation; arranging each permanent magnet to a receiving positions using the optimized allocation.