Contents INTRODUCTION
The SNS accelerator complex [1] consists of a 2.5 MeV H injector, a 1 GeV linear accelerator, an accumulator ring [2] and associated beam transport lines [3]. The ring and transport line layout is shown in Figure 1. The SNS baseline parameters are summarized in Table 1. The H-beam from the linac is transported to the ring in the High Energy Beam Transport (HEBT) line. Before the 90 degree bend in the HEBT is a tuning beam dump (the Linac Dump) which will be used for linac commissioning and linac tuneup during operations. The HEBT delivers the beam to the stripping foil for charge-exchange injection into the accumulator ring [4]. Unstripped H and partially stripped beams are fully stripped in a second foil and transported to the injection dump via the injection dump line [5]. In baseline operation, beam is accumulated in the ring over 1060 turns reaching an intensity of protons per pulse. When accumulation is complete the extraction kicker fires during the 250 nsee gap to remove the accumulated beam in a single turn and direct it into the Ring to Target Beam Transport (RTBT) line, which takes the beam to the liquid-mercury target. Located midway along the RTBT is another tuning beam dump (the Extraction Dump). Both the Extraction and Linac dumps have 7.5 kW beam power capability while the Injection Dump has 200 kW capability.
