The drawing shows a part of magnetic core, to be used in a central core leg of a shunt reactor. In such radially laminated core the laminations have varying lengths and are positioned radially, in wedge-shaped sections. Such arrangement is especially useful for reduction of flux fringing in laminated cores.
Several such radially laminated discs would be used for construction of single core leg, with the air gaps distributed between them.
The drawing was adapted from: