(FILES) A handout made available by the European Organization for Nuclear Research (CERN) on April 19, 2023, shows the tunnels of the Future Circular Collider (FCC) and the current Large Hadron Collider (LHC) in Geneva. The CERN physics laboratory chief welcomed China hitting pause on its major particle accelerator project, calling it an "opportunity" to ensure Europe's rival plan goes ahead. Ten years ago, China announced its intention to build the Circular Electron Positron Collider (CEPC), which would be the world's largest particle accelerator at 100 kilometres (62 miles) long. But Beijing recently put the project on ice, CERN's director-general Fabiola Gianotti told a small group of journalists in a recent briefing. (Photo by HANDOUT / European Organization for Nuclear Research (CERN) / AFP via Getty Images) / RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / European Organization for Nuclear Research (CERN)" - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS