Chinese scientists stably operated an electron beam at a repetition rate of one megahertz for the first time on July 24 in Dalian, Liaoning province, marking a critical advancement for the Dalian Advanced Light Source project, a next-generation extreme ultraviolet free-electron laser.

The research team is led by academician Yang Xueming and researcher Zhang Weiqing from the Dalian Institute of Chemical Physics of the Chinese Academy of Sciences.

Generating high-repetition-rate, high-quality electron beams is one of the most formidable technical challenges in building the DALS.

The success of this experiment demonstrates that the joint team has now gained critical expertise in the core enabling technologies, laying a strong foundation for the project's future construction.

Scientists from the research team said it also represents a significant step forward in China's broader effort to advance cutting-edge free-electron laser facilities.

To support the development of the DALS, the Dalian government launched a prototype initiative focused on building a superconducting continuous-wave electron injector.

Launched in 2020, the project is a collaborative effort between the DICP and the Institute of Advanced Light Source Facilities in Shenzhen.

Over the past five years, the team has made significant progress in developing a suite of key technologies, including a photocathode electron gun, ultrafast laser systems, solid-state radio-frequency power sources, superconducting accelerator modules, and cryogenic helium refrigeration systems.