LINAC ENERGY MANIPULATION FOR LONGITUDINAL PHASE SPACE PAINTING FOR SNS RING.

Control of instabilities and halo losses are important issues for a high beam power storage ring like the Spallation Neutron Source (SNS). One of the important issues is proper transverse and longitudinal phase space painting. The former is well studied and in this paper we discuss a robust way to achieve longitudinal phase space painting into a ring. Energy jitter correction and programmable energy spread are essential for controlling losses during the 1000 turn injection into the accumulator ring. Energy correction is needed to combat linac cavity amplitude and phase errors. Adequate energy spread is required to provide Landau damping in the accumulator ring during the accumulation process. Two CCL cavities, one for energy correction and the other for creating energy spread, are used for this purpose