Novel design of a personnel protection system for large particle accelerators: balancing safety, reliability, and cost

Abstract

As the primary safety protection system for particle accelerators, the Personnel Protection System (PPS) not only prioritizes safety but also recognizes the importance of system reliability to ensure the stable operation of the accelerator and foster trust among system stakeholders. When designing the PPS, a distinction can be made between critical safety functions and common functions. There are at least three critical safety functions: firstly, ensuring that personnel are prohibited from accessing the tunnel during accelerator operation; secondly, preventing accelerator activation in the presence of personnel within the tunnel; and thirdly, enabling prompt termination of accelerator operations during emergency situations. To meet the demanding safety integrity level requirement of SIL3, multiple layers of defense and safety redundancy are employed. In order to mitigate the potential risks arising from human errors, significant emphasis is placed on improving the automation and intelligence of the system. This research focuses on the development of a comprehensive novel system that incorporates multiple defense mechanisms to meet the stringent safety and reliability demands of large particle accelerators represented by High Energy Proton Source (HEPS). It designs novel local optimization schemes, including the semi-redundant control system, zero-count interlock, intelligent search and secure, and electromagnetic control key, among others. These pioneering approaches are seamlessly integrated into the comprehensive system, effectively enhancing its capabilities and overall efficiency. Furthermore, this study conducts an analysis of the reliability of interlocking equipment, employing measures such as hierarchical DC power, parallel redundancy, and optimized signal processing to enhance its overall reliability. Finally, a method for determining the Safety Integrity Level (SIL) and assessing the reliability of PPS is developed, and the system's performance is validated.