Formal Verification of Real-Time Data Processing of the LHC Beam Loss Monitoring System: A Case Study

We describe a collaborative effort in which the HOL4 theorem prover is being used to formally verify properties of a structure within the Large Hadron Collider (LHC) machine protection system at the European Organization for Nuclear Research (CERN). This structure, known as Successive Running Sums (SRS), generates the primary input to the decision logic that must initiate a critical action by the LHC machine protection system in response to the detection of a dangerous level of beam particle loss. The use of mechanized logical deduction complements an intensive study of the SRS structure using simulation. We are especially interested in using logical deduction to obtain a generic result that will be applicable to variants of the SRS structure. This collaborative effort has individuals with diverse backgrounds ranging from theoretical physics to system safety. The use of a formal method has compelled the stakeholders to clarify intricate details of the SRS structure and behaviour.