On August 10, ISO 19991:2026, Fusion technology — Experimental magnetic confinement fusion facilities — Supersonic molecular beam injection fueling technique for fusion devices, was officially published. Spearheaded by China, it is the first ISO international standard in the field of fusion fueling and the second fusion-related ISO standard led by the Southwestern Institute of Physics (SWIP) under China National Nuclear Corporation (CNNC).

Supersonic molecular beam injection is a key fueling technology for controlled fusion devices. Originally developed in China, it uses gas adiabatic expansion to generate a high-speed, directional molecular beam. The technology offers high injection speed, strong directionality, high fueling efficiency, and low particle recycling, significantly enhancing fuel control in fusion devices. It has been applied in more than 10 magnetic confinement fusion experimental devices in China and abroad.

The standard specifies the methods and basic requirements for supersonic molecular beam injection fueling in magnetic confinement fusion devices. It covers system components, key characteristics and inspection methods, providing a unified technical basis for the design, testing, acceptance, and application of related systems.

According to SWIP technical lead Xiao Guoliang, the standard translates China's original technology and experience gained from various fusion devices into measurable, verifiable and reusable international technical rules. It marks a major step forward in the development of supersonic molecular beam fueling technology — from original research and device application to international standardization.