Chromatic correction and optical compensation in the sns accumulator ring usingsextupoles

摘要

The accumulator ring of the Spallation Neutron Source (SNS) will accumulate ahigh-intensity beam of 2.1 x 10(sup 14) protons in a single bunch with large transverse emittance of 160(pi) mm mrad at 95% beam intensity and energies of 1 to 1.3 GeV. In order to keep low beam losses ((approx) 10(sup (minus)4) in the ring, it is necessary to control the chromaticity and to minimize the dependence of the optical properties on the momentum spread. In this paper, we describe the procedure to accomplish this by using chromaticity sextupoles. We finally discuss the impact of these sextupoles in non-linear dynamics.