Common Coil Design to Handle Large Lorentz Forces in High Field Magnets
In common coil design, geometry and forces are such that the impregnated solid volume can move as a block without causing quench or damage (over 1 mm motion in LBL RT1 common coil test configuration).
Horizontal forces are larger
In cosine theta designs, the geometry is such that coil module cannot move as a block. These forces put strain on the conductor at the ends and may cause premature quench. The situation is somewhat better in single aperture block design, as the conductors donít go through complex bends.
We must check how far we can go in allowing such motions in the body and ends of the magnet. This may significantly reduce the cost of expensive support structure. Field quality optimization should include it (as was done in SSC and RHIC magnet designs).