Proton injection and RF capture in the National Spallation Neutron Source

The accelerator system for the 1 to 5 MW National Spallation Neutron Source (NSNS) consists of a linac followed by a 1 GeV proton accumulator ring. Since the ring is a very high current machine, the injection and RF capture of the protons is deeply affected by transverse and longitudinal space charge effects. Results of numerical simulation of the process are presented together with considerations on methods and results of space charge treatment in high intensity proton storage rings.