We are deeply saddened to announce the passing of Roger Perret on 20 December 2025.

A mechanical design engineer of exceptional expertise and professionalism, Roger joined CERN in 1975, where he served with distinction until his retirement in 2010. Over his 35-year career, within what later became the EN-MME Design Office, he made significant contributions to numerous major projects for a wide range of accelerators and experiments, from the ISR (the world’s first hadron collider) to the LEP, the SPS, CNGS and the HL-LHC.

Many of us got to know Roger through the LHC collimator project, to which he made a fundamental contribution. His ideas formed the basis of the mechanical design of these essential components and were widely adopted in the designs of the HL-LHC collimators, as well as of other beam intercepting devices. The performance of these systems over the years bears testimony to the soundness and relevance of his ideas.

Throughout his career, Roger passed on his knowledge and expertise to many designers, technicians and engineers, leaving a lasting legacy within the Design Office and the MME group.

We will remember him as a dedicated and generous colleague who was deeply attached to CERN and passionate about mechanics and craftsmanship. He leaves a lasting mark on all those who had the privilege of working alongside him.

His former colleagues from the EN-MME group