Here is a six coil reactor:

yellow and red cones represent ion and electron guns.
the wire frame around the outside represents a spherical vacuum chamber
Here is one of the six segments:

This suggests to me that six identical segments could be built. All the internal and external equipment could be attached to one sixth of the vacuum chamber shell. Then the six pieces bolted together to create a complete reactor.
Here is another version:

The purple cylinders represent Alpha particle traps