VARIABLE STRENGTH FOCUSING OF PERMANENT MAGNET QUADRUPOLES WHILE ELIMINATING X-Y COUPLING

摘要

ABSTRACT OF THE DISCLOSUREVarious configurations of permanent magnet quadru-poles are provided which produce no coupling in the twotransverse directions when focusing a charged particle beamis provided; each configuration comprises a plurality ofrotable quadrupole disks, and means for rotating the quadru-pole disks with respect to each other in a predeterminedrelationship.