CERN Accelerating science

Article
Title	Radiation Resistant Magnets for the RIA Fragment Separator
Author(s)	Zeller, Al ; Blideanu, Valetin ; Gupta, Ramesh C ; Ronningen, Reginald ; Sherrill, Bradley
Affiliation	(BNL, Upton, Long Island, New York) ; (NSCL, East Lansing, Michigan)
Publication	2005
In:	21st IEEE Particle Accelerator Conference, Knoxville, TN, USA, 16 - 20 May 2005, pp.2200
Subject category	Accelerators and Storage Rings
Abstract	The high radiation fields around the production target and the beam dump in the fragment separator at the Rare Isotope Accelerator requires that radiation resistant magnets be used. Because large apertures and high gradients are required for the quadrupoles and similar demanding requirements for the dipole and sextupoles, resistive coils are difficult to justify. The radiation heating of any materials at liquid helium temperatures also requires that superconducting versions of the magnets have low cold-masses. The final optical design has taken the practical magnets limits into account and sizes and fields adjusted to what is believed to be achievable with technology that is possible with sufficient R&D. Designs with higher obtainable current densities and having good radiation tolerances that use superconducting coils are presented, as well as the radiation transport calculations that drive the material parameters.