Concepts and techniques: active electronics and computers in safety-critical accelerator operation

The RHIC requires an extensive Access Control System to protect personnel from radiation, oxygen deficiency and electrical hazards. In addition, the complicated nature of operation of the collider as part of a complex of other accelerators necessitates the use of active electronic measurement circuitry to ensure compliance with established operational safety limits. Solutions were devised which permit the use of modern computer and interconnection technology for safety-critical applications, while preserving and enhancing, tried and proven protection methods. In addition a set of Guidelines, regarding required performance for accelerator safety systems and a handbook of design criteria and rules were developed to assist future system designers and to provide a framework for internal review and regulation. This paper is offered in the hope and belief that many of the techniques developed as part of the Access and Operational Safety systems designed for RHIC (and other recently completed large research accelerators) may be directly applicable to smaller research and clinical treatment facilities. Because of the relatively short length of this paper, I will concentrate on four topics: novel features of our system design; potentially useful applications of probability theory empowered by these system concepts: a listing of configuration control and design approaches, which when followed, will enable one to design high reliability hardware and systems (to meet required functionality); software design concepts and approaches