CEPC Accelerator Technical Design Report Officially Released (2023-12-28)

On December 25, 2023, the Circular Electron-Positron Collider (CEPC) research working group officially released the CEPC "Accelerator Technical Design Report (TDR-accelerator)". This is the first TDR for a global circular electron-positron Higgs factory, marking an important milestone for CEPC.

In September 2012, Chinese high-energy physicists formally proposed the CEPC-SppC concept and subsequently initiated project design and preliminary research. CEPC serves not only as a Higgs factory (125 GeV beam energy) but also covers energy regions such as Z (45 GeV), WW (80 GeV), and ttbar (180 GeV). Its tunnel is also compatible with the Super Proton-Proton Collider (SppC). After more than five years of effort, the team completed the "Conceptual Design Report (CDR)" in November 2018. Following another five years of work, the "Accelerator Technical Design Report" has been completed and published on the global particle physics preprint website (arXiv: 2312.14363).

Over the past five years, the project team has optimized the accelerator's physical design, with specifications meeting the requirements of physical experiments in the W, Z, Higgs, and ttbar energy regions, achieving internationally leading design luminosity. With support from special funding, key technology research and development have been conducted, covering all CEPC technical requirements. Significant breakthroughs have been made, particularly in superconducting radio frequency, microwave power sources, and other fields, reaching internationally leading technical levels. Mass production technologies required by CEPC, such as magnets and vacuum systems, meet accelerator design specifications through prototype research. Additionally, numerous conventional accelerator technologies, including linear accelerators, beam diagnostics, control systems, power supplies, injection and extraction equipment, cryogenic systems, alignment, and mechanical components, have been developed and validated through projects undertaken by the Institute of High Energy Physics, such as the High Energy Photon Source, meeting CEPC construction requirements. Beyond physical design and key technology research, the TDR phase also encompasses general facilities, radiation protection, civil engineering design, and cost estimation.

Based on the above achievements, the CEPC accelerator team completed the technical design report, which was reviewed and approved by international first-class experts comprising the Technical and Price International Review Committees, chaired by Dr. Frank Zimmermann (CERN) and Dr. Loinid Rivkin (PSI), respectively. The CEPC civil construction cost was reviewed by a committee of domestic experts chaired by Chief Engineer Zongyin Guan (China Renewable Energy Engineering Institute). Experts highly commended the work during the CEPC technical report phase, stating that "CEPC key technologies have been developed, with prototypes meeting or exceeding specification requirements, and the project can proceed to the Engineering Design Report (EDR) phase." The International Advisory Committee (IAC), chaired by Professor Brian Foster, endorsed and supported the TDR review report conclusions and CEPC's next-phase development goals.

CEPC will enter the EDR phase in 2024, preparing for the target plan of construction commencement during the "15th Five-Year Plan" period and completion around 2035.