A realistic laser assisted charge exchange (LACE) scheme for 1.3~GeV H- beam injection into the Ring for Spallation Neutron Source is under development. The design considered here is supposed to demonstrate the possibility of H$^-$ charge exchange injection into the SNS ring as an alternative to carbon foil stripping. A realistic stripping magnet design is considered as an integrated part of the injection area. Beam dynamics at the injection area are optimised. Laser assisted stripping, painting and beam dynamics of protons in the ring is simulated. Several alternative stripping schemes are evaluated.

The {2, 2} Danilov distribution is self-consistent — it is a Vlasov equilibrium distribution that produces linear space charge forces. Additionally, the distribution has zero (four-dimensional) transverse emittance. Thus the Danilov distribution may be of use for overcoming space charge limitations at high intensities, increasing collider luminosity, or pushing the limits of transverse bunch compression using round-to-flat transformers. When such a distribution is matched to one of the eigenmodes of a ring it is possible to use phase space painting to build the distribution over many turns, maintaining self-consistency throughout. This provides a way to create high-intensity beams with unique properties that could increase accelerator performance, with direct implication for experiments.  Here we report on the results of a proof-of-principle experiment using the flexible transverse phase space painting system at the Spallation Neutron Source to demonstrate the creation of an approximate Danilov distribution, including the effect of recently installed solenoid magnets.