LCF4CERN – A Linear Collider Facility for CERN / Environmental Impact and Considerations for Future Accelerators

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9/17（水）に欧州の加速器技術開発交流事業, The Europe-America-Japan Accelerator Development Exchange Programme(EAJADE)におけるサステナビリティーWGの研究者4名がKEKを訪問されます。この方々はリニアコライダー計画に長年携わられており、現在進められている欧州素粒子戦略アップデートにも深く関与されています。この機会にWGメンバーである、Karsten Buesser氏(DESY)によりLinear Collider Facility＠CERNの検討について、また、Maxim Titov氏(CEA-Saclay)より欧州の加速器研究機関におけるサステナビリティーの取り組みについてのご講演を頂けることになりました。

講演1：Karsten Buesser氏(DESY)
LCF4CERN – A Linear Collider Facility for CERN
Europe is preparing for the update of the European Strategy for Particle Physics of CERN Council. The strategy should be finalized in 2026 and it is expected that it will contain a recommendation for the next energy frontier collider project for CERN. European particle physics communities have already provided input for the strategy and there is a broad consensus that the Future Circular Collider FCC is the preferred project to provide interesting physics capabilities while securing CERN’s long-term future and leading role in particle physics. On the other hand, it is understood that the predicted FCC cost are too large to be covered from the CERN budget alone and that significant contributions would have to be found elsewhere. It seems therefore to be prudent to develop a less-costly option („Plan B“) for CERN’s future. The Linear Collider Vision team has started to assemble a proposal for a versatile Linear Collider Facility at CERN. In the baseline configuration it should start with a ~33km long tunnel, to be equipped with ILC-like superconducting technology. A sustainable upgrade path to higher energies and luminosities would enable a 20y+ physics program for electroweak, Higgs, and Top-Physics. The tunnel infrastructure would also allow for long term upgrades into the multi-TeV regime using other technologies, e.g., copper based RF (CLIC, C3) or Plasma Wakefield acceleration. Additionally, other physics modes like gamma-gamma collisions, should be made possible.

講演2：Maxim Titov氏(CEA-Saclay)
Environmental Impact and Considerations for Future Accelerators
The sustainability of future accelerator-based projects is increasingly central to their scientific, economic, and societal viability. The European Laboratory Directors Group (LDG) established the Working Group (WG) on the Sustainability Assessment of Accelerators in early 2024: https://ldg.web.cern.ch/working-groups/sustainability-assessment-of-accelerators. The WG mandate was to develop guidelines and a list of key parameters for the assessment of the sustainability of future accelerators in particle physics and to promote transparent, open discussions within research communities. This talk will highlight LDG Sustainability WG report, which will become (became) public in Sep. 2025. This document establishes a reference framework, summarizing the best practices and standards for assessing and guiding the sustainable development of large-scale facilities. Nature-based interventions and circular economy principles are proposed as complementary strategies to offset residual impacts (e.g. Green ILC in Japan).