Our Organization
The Heads of the Health, Safety and Environmental protection (HSE) Department, the Legal Service (LS), the Audit and investigation Services (AIS), and the Internal Justice Secretariat (IJS) retain functional independency and report to the Director-General.
SO Leadership Team
Mar Capeans
Director for Site Operations sector
Mar Capeáns is a Spanish particle physicist who took up the role of CERN Director for Site Operations in January 2026. She earned a PhD in Particle Physics from the University of Santiago de Compostela in 1995, and was awarded Executive MBA in Management of Technology by the University of Lausanne and EPFL in 2007.
She joined CERN in 1992. From 2012 to 2017, she led the Detector Technologies Group, then moved to the Technology Department as Head of the Planning, Project and Resources Group. In 2019, she served as Upgrade Technical Coordinator for the CMS experiment. From 2021 to 2025, she headed the Site and Civil Engineering Department.
She is editor of the Journal of Instrumentation and serves as an adviser on scientific councils and for competitive funding programmes.
Benoit Delille
Head of Occupational Health and Safety and Environmental Protection Department (HSE)
Benoît Delille worked for 6 years in the private sector in Belgium, as manager of a Mechanical Design Office in the company ENGIE Fabricom, followed by an experience in the aerospace company SONACA.
He then joined CERN’s Safety Commission in 2002 as a Mechanical Safety Engineer, where he assessed the structural reliability of equipment for CERN’s accelerators and experimental areas during the construction of the LHC.
In 2010, he broadened his skills by joining CERN’s Human Resources (HR) Department as HR Advisor to the Technology Department (400 staff). Besides supporting managers in the application of various policies, he contributed to the implementation of HR strategies by analyzing and developing new ideas, especially in the domains of contract policy and workforce planning.
He joined CERN’s Accelerator and Technology Sector in 2014 as Executive Officer to the Director for Accelerators and Technology. In this role, he was closely working with the Director, preparing negotiations and arbitration exercises, as well as proposing and budgeting the implementation of measures, both administrative and technical, decided by the Director. At the same time he took over the leadership of the High-Luminosity LHC (HL-LHC) Project Budget Office. Under his leadership, the Budget Office implemented Earned Value Management (EVM) methods, which were used to determine the project’s Cost and Schedule performance and to report the Project’s financial situation to all levels of the Organization.
Combining the competencies he acquired in the various sectors of the Organization – technical, administrative and financial – Benoît Delille took over as Head of CERN’s HSE Department in January 2021.
Alex Kohls
Head of Organisational Support and Improvement Department (OSI)
Alexander Kohls, Head of CERN’s Organisational Support and Improvement (OSI) Department, spearheads initiatives to enhance CERN’s organisational effectiveness, resilience, records and information management, and open research practices. Prior to this role, he led the Scientific Information Service, which encompassed the CERN Library, CERN’s historical archives, and a diverse portfolio of international open-science initiatives, including SCOAP3 and INSPIRE.
Alex joined CERN in 2014 after a 20-year career in the financial industry, during which he held senior international roles in financial planning, operations, project management, and business development. His academic background includes a degree in Business Administration, and he is a passionate advocate for international collaboration, open science, and organisational transformation.
Cedric Garino
Head of Site and Civil Engineering Department (SCE)
Cédric Garino is a software engineer by training, with more than 10 years of experience in software development in both the private sector and at CERN, which he joined in 2009. He subsequently took on increasing technical and managerial responsibilities, first in the field of supply chain and later in site services. After serving as Deputy Head of CERN’s Site and Civil Engineering Department for three years, he took up the role of Head of the Department in January 2026. His career combines technical expertise, infrastructure management and organisational leadership.
The Site and Civil Engineering Department manages CERN’s built estate and infrastructure in support of the Organization’s scientific mission. Its responsibilities cover the full lifecycle of buildings and technical infrastructure, from long-term planning, civil-engineering design and project delivery to operation, maintenance and modernisation. The Department also provides campus-related services and oversees the operation of Science Gateway.
As Head of Department, Cédric guides these activities with a strong focus on safety, reliability, sustainability and performance. His ultimate goal is to provide CERN’s communities and visitors with a rich, welcoming and high-quality campus experience that supports scientific excellence and fosters collaboration.
Catherine Spencer
Head of the Audit and Investigations Services (AIS)
Catherine is a British-French chartered accountant who became Head of CERN’s Internal Audit and Investigation Services in January 2026. She brings extensive experience in governance, risk management, audit, finance and fraud investigation. She studied for a BSc in Economics at the London School of Economics and trained as a chartered accountant with PwC.
She joined CERN in 2006, following an earlier career in the private sector. From 2006 to 2008, she worked in Internal Audit before moving to the Finance Department, where she served as CERN Treasurer and subsequently became Group Leader for the Treasury, Processes and Reporting services. In 2019, she took on the role of Deputy Head of Finance and Administrative Processes. In 2022, Catherine became the Head of Internal Audit.
Alexandra Hahnel-Borgeaud
Head of Internal Justice Secretariat (IJS)
Alexandra is a French-German lawyer who was appointed Head of the newly established Internal Justice Secretariat in January 2026.
She obtained her law degree in Grenoble in 1998 and completed her PhD studies in Berlin in 2003. Following experience at the European Commission in Brussels and at a private law firm in Berlin, she joined CERN’s Legal Service in January 2004.
From 2007 to 2023, she led Procurement Legal, advising on CERN’s procurement rules and contracts, resolving contractual disputes and contributing to the development and implementation of the Organization’s legal framework.
From 2024 to 2026, she served within the HR Legal team, providing legal advice on employment and internal justice matters. Throughout this period, she also chaired CERN’s Joint Advisory Appeals Board for more than a decade.
Kirsten Baxter
Legal Counsel, Head of Legal Service (LS)
Kirsten Baxter was born and raised in the north of Scotland.She studied Scots law and public international law at the University of Glasgow before being awarded a Commonwealth Scholarship to pursue an LL.M. at the University of Toronto, Canada, graduating in 1997. Her research work focused upon the use of international and foreign domestic law and normativity in constitutional jurisprudence relating to capital punishment.
Kirsten’s legal career includes work at the North Carolina Resource Center (now the Center for Death Penalty Litigation) in Durham, North Carolina, and in the chambers of Justice Kriegler at the Constitutional Court of South Africa. She taught in the Department of Criminal Justice at Radford University, Virginia, before joining the United Nations in New York, where she spent ten years serving in the registries of the United Nations Administrative Tribunal and its successor, the United Nations Appeals Tribunal.
Kirsten joined CERN in 2009, returning in 2014 after a brief period away. She has held a succession of increasingly senior positions within the Legal Service and has served as Legal Counsel of the Organization since 2021.
A frequent speaker and published author on public international law and the law of the international civil service, Kirsten is co-Chair of FILIO (the Forum for Institutional Law in International Organisations) and was recently appointed President and Judge of the Administrative Court of the European Public Law Organization.