Permanent Magnet Quadrupoles with Adjustable Field Strength and Centerline Movement Compensation

65179 Quadrupole focusing magnets for the Next Linear Collider will require magnetic centerline stability of <1 micron when fields are adjusted by 20% for beam-based alignment, a requirement that cannot be easily satisfied with existing electromagnets or permanent magnets. This project will demonstrate the suitability of a patent-pending, permanent magnet, multipole beamline optic design, with remotely variable magnetic field strength and independent centerline adjustment, for the Next Linear Collider and other potential users with a cost-competitive and reliable device. In Phase I, a simple laboratory test assembly was used to demonstrate a centerline stability of ¿0.1 micron over 24 hours and ¿0.4 micron over two weeks as the field strength was adjusted by 20%. Active centerline control was also demonstrated, and various actuator schemes were developed to reduce costs and improve radiation resistance. In Phase II, a prototype Next Linear Collider quadrupole will be developed. Commercial Applications and Other Benefits as described by the awardee: Multipole optical elements, such as quadrupoles, sextupole, and octopoles, are used in all accelerator systems, including research, medical, and industrial accelerators, and synchrotron storage rings. The adjustable multipole PM elements should have the advantage of eliminating the need for high current power supplies and cooling water with significant capital and operating cost savings. Also, the PM design is inherently compact and can be used where conventional EMs cannot fit.