On June 7, 2025, led by the accelerator RF team of the China Spallation Neutron Source (CSNS), GLVAC in collaboration with the research group of Professor Zhaoyun Duan from the School of Electronic Science and Engineering at University of Electronic Science and Technology of China, as well as the CEPC klystron team, jointly developed the world's first compact P-band high-power metamaterial klystron. The device successfully passed acceptance testing with all performance indicators meeting the required standards. This achievement marks another major breakthrough in China's innovative research on high-power klystrons.

The successful development of the metamaterial klystron marks another milestone in GLVAC's long march toward the localization of RF components, and is also a vivid reflection of China’s "full-chain independent control" in major scientific facilities:

In 2020, we broke through technological barriers and successfully developed China's first 650 MHz continuous-wave klystron, filling a critical technology gap in the field;

In 2023, we developed China's first 648 MHz klystron, and in 2024 secured an order for 26 units of 648 MHz klystrons for the CSNS upgrade project;

In 2024, building on the 650 MHz klystron platform and applying high-efficiency technologies, we successfully developed a 650 MHz high-efficiency klystron with an efficiency of 78.5%, achieving the highest operational efficiency in the world;

In 2025, after four years of technological accumulation and countless rounds of experimental breakthroughs, we applied metamaterial technology to develop the world's first P-band metamaterial klystron — a 324 MHz metamaterial klystron — marking China's global leadership in this field. This fully demonstrates that China now possesses full-chain independent innovation capabilities from fundamental theoretical breakthroughs to engineering practice.

In Phase I of the CSNS project, GLVAC helped achieve 100% domestic production of core accelerator equipment, with its hydrogen thyratrons performing at international top-tier levels.

Now, the metamaterial klystron will be officially integrated into the CSNS Phase II project in September 2026, boosting beam power from 100 kilowatts to 500 kilowatts, providing a powerful “Chinese power source” for cutting-edge research in new materials, new energy sources, and beyond.

The P-band high-power klystron serves as the "power heart" of the China Spallation Neutron Source (CSNS) linear accelerator. Like a "super engine" for particle beams, it converts electrical energy into high-frequency microwave energy, accelerating particles to near-light speed so they can bombard target nuclei and generate neutrons. Previously, such high-end components were completely monopolized by overseas companies, resulting in high procurement costs and risks of supply cutoffs.

In 2021, GLVAC formed a joint research team with the Institute of High Energy Physics, Chinese Academy of Sciences, and University of Electronic Science and Technology of China to tackle this “bottleneck” technology. We successfully broke through three core technological barriers:

Metamaterial Resonant Cavity Design: For the first time globally, metamaterials were integrated into a 324 MHz high-power klystron. Leveraging electromagnetic field localization enhancement effects, the design achieves miniaturization of the cavity structure while maintaining a peak power of 3.0 MW (pulse width 650 μs, repetition frequency 25 Hz);

Ultra-Precision Manufacturing Process: The klystron team at GLVAC Research Institute overcame 12 key process challenges, including high-precision electron gun assembly and nanoscale surface treatment, ensuring continuous stable operation under megawatt-level power for 48 hours;

Material Innovation Breakthrough: A special composite ceramic metallization technology was developed, delivering heat-resistant and radiation-resistant performance that exceeds international counterparts by 30%, providing "armor-grade" protection for device longevity.

After four years of intensive research and development, this "Chinese engine" has finally been unveiled with remarkable performance: half the size, double the power density, and significantly reduced cost.

Deputy Director Sheng Wang of the Institute of High Energy Physics at the Chinese Academy of Sciences commented: "This represents a qualitative leap in P-band klystron technology—and more importantly, it demonstrates China's systematic innovation capability in high-end manufacturing!"