A process for directional solidification of a cast part comprises energizing a primary inductive coil coupled to a chamber having a mold containing a material; generating an electromagnetic field with the primary inductive coil within the chamber, wherein said electromagnetic field is partially attenuated by a susceptor coupled to said chamber between said primary inductive coil and said mold; determining a magnetic flux profile of the electromagnetic field after it passes through the susceptor; sensing a component of the magnetic flux in the interior of the susceptor proximate the mold; positioning a mobile secondary compensation coil within the chamber; generating a control field from a secondary compensation coil, wherein said control field controls said magnetic flux; and casting the material within the mold.