SNS accumulator ring collimator optimization with beam dynamics

It is required to have an uncontrolled beam loss less than 1 nA/m at 1 GeV energy for hands-on maintenance of the Spallation Neutron Source (SNS) Accumulator Ring. Collimators will be used for this end. Various beam dynamics questions related with the collimators have been studied. Various factors are optimized with the given ring lattice and error study is done. Numerical simulations also indicate that movable shielding is necessary for a few hot places downstream of the primary collimator. These simulations indicate that with properly designed collimators the uncontrolled beam-loss requirements of the SNS accumulator ring may be achievable.