Chinese scientists have achieved a major breakthrough in particle accelerator technology by developing the world's first high-power P-band klystron using metamaterial resonant cavities.

The device, developed by a joint team from the Institute of High Energy Physics of the Chinese Academy of Sciences, University of Electronic Science and Technology of China, and other partners, passed all performance tests on June 7, 2025, at the China Spallation Neutron Source (CSNS) site in Dongguan, Guangdong Province.

The klystron, operating at 324 MHz, acts as the "engine" of the CSNS linear accelerator, providing the high-power electromagnetic waves needed to drive particle beams. For years, such key components were imported, posing both technological and supply chain risks.

The newly developed klystron uses resonant cavity-loaded metamaterials, a cutting-edge design approach proposed by the research team for the first time globally. After more than four years of R&D, the system passed a 48-hour high-power stability test at 2.5 MW peak output, meeting all technical requirements.

It is expected to be officially integrated into the CSNS linear accelerator in September 2026.

This milestone marks a critical leap from import dependence to domestic innovation in China's advanced radiofrequency (RF) technology. As the world's first P-band klystron using metamaterial structures, the breakthrough holds enormous potential for large-scale scientific facilities, as well as applications in medical equipment and industrial systems