Project status of the 1-GeV SNS linac

The U.S. Department of Energy has initiated construction of a $1.3 B Spallation Neutron Source (SNS) to be located at Oak Ridge, Tennessee. Five national laboratories, ANL, BNL, LANL, LBNL, and ORNL are collaborating in the design and construction of this major new U.S. Neutron science facility. The present design is a 60-Hz, 1-GeV H^- linac injecting into an accumulator ring to produce pulses of <1-μs on the neutron-producing target. The accelerator design has been refined from the CDR concept to provide improvements in assembly and maintainability. A converter-modulator design using IGBT technology replaces the conventional RF system to power the accelerating cavities. Cost estimates for the linac have utilized both accelerator modeling codes and more conventional cost-estimating approaches. Comparison of these two methods has led to increased confidence in the linac cost estimate of about $300 M (including R&D and controls but without contingency). A Monte-Carlo simulation of the project cost using risk-based analysis has further contributed to the estimate and identified critical areas. The project uses Primavera Project Planner as the scheduling software. A linac R&D program to develop key technologies is underway at Los Alamos