Distributed Implementation Plan for a Large, Distributed Accelerator Control System

The proposed Spallation Neutron Source (SNS) is an accelerator-based 1 – 2 MW pulsed neutron source to be built in Oak Ridge, Tennessee. The facility has five major sectionsó a "front end" consisting of a 65 Kev H ion source followed by a 2.5 MeV RFQ; a 1 GeV linac; a storage ring; a 1 MW spallation neutron target; and the conventional facilities to support these machines. These components will be designed and implemented by five collaborating institutions: Lawrence Berkeley National Laboratory (front end); Los Alamos National Laboratory (linac); Brookhaven National Laboratory (storage ring); Oak Ridge National Laboratory (neutron source and conventional facilities); and Argonne National Laboratory (instruments). It is proposed to implement a fully integrated control system for all aspects of this complex. The integration will be based upon the widely-used EPICS control system toolkit. This paper introduces the SNS project, discusses the technical and organizational issues of planning a large control system to be developed collaboratively at five different institutions, and describes approaches being taken to address those issues.