THE ESS FAST BEAM INTERLOCK SYSTEM - DESIGN, DEPLOYMENT AND COMMISSIONING OF THE NORMAL CONDUCTING LINAC

The European Spallation Source (ESS) is a research facility based in Lund, Sweden. Its linac will have an high peak current of 62.5 mA and long pulse length of 2.86 ms with a repetition rate of 14 Hz. The Fast Beam Interlock System (FBIS), as core system of the Beam Interlock System at ESS, is a critical system for ensuring the safe and reliable operation of the ESS machine. It is a modular and distributed system. FBIS will collect data from all relevant accelerator and target systems through ~300 direct inputs and decides whether beam operation can start or must stop. The FBIS operates at high data speed and requires low-latency decision-making capability to avoid introducing delays and to ensure the protection of the accelerator. This is achieved through two main hardware blocks equipped with FPGA based boards: a mTCA ’Decision Logic Node’ (DLN), executing the protection logic and realizing interfaces to Higher-Level Safety, Timing and EPICS Control Systems. The second block, a cPCI form-factor ’Signal Condition Unit’ (SCU), implements the interface between FBIS inputs/outputs and DLNs. In this paper we present the implementation of the FBIS control system, the integration of different hardware and software components and a summary on its performance during the latest beam commissioning phase to DTL4 Faraday Cup in 2023.