News on China's scientific and technological development.

This has to be China first nuclear fusion technology company.
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StarRing Energy has successfully completed cryogenic excitation testing (at 20 K / -253°C) of the world’s first full-scale high-temperature superconducting (HTS) toroidal field magnet designed specifically for spherical tokamak fusion reactors. This marks a critical milestone in engineering fusion-grade magnets and lays the groundwork for their next-generation device, CTRFR-1 (StarRing One).

Achievements:​

StarRing Energy demonstrated full supply chain control, independently developing:

HTS tape acceptance, coil winding machines, and key components like insulation terminals and connectors. Custom cryogenic systems (including a 360 W/20 K cold helium system), full-size Dewars, and magnetic shielding. An AI-native control system and the proprietary EPIC test instrument for comprehensive signal acquisition. They also deployed an OFDR distributed sensing system for millimeter-level strain/temperature monitoring to prepare for future quench detection.

The fully automated test validated the entire technical route from design to cryogenic operation, proving the reliability of StarRing’s approach. This achievement accelerates the transition of fusion energy from scientific verification to engineering realization, positioning StarRing as a leader in compact, high-efficiency fusion technology.​

Recently, Professor Fan Wei's team at the Joint Laboratory of High Power Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, conducted research on the challenge of monitoring amplitude-frequency modulation ( FM-to-AM ) in high-power laser drivers for inertial confinement fusion ( ICF ). Their findings, titled " Frequency modulation-to-amplitude modulation monitoring in inertial confinement fusion high-power laser systems using dual-comparator delay-unlocked detection," were published in High Power Laser Science and Engineering .

In ICF high-power laser drivers, phase modulation is typically used to broaden the spectrum, suppressing transverse stimulated Brillouin scattering and achieving a smoother intensity distribution on the target surface. However, due to the non-uniform spectral transmittance and group velocity dispersion of optical components, broadband lasers undergo FM-to-AM conversion during transmission, resulting in periodic intensity fluctuations and local spikes in the time domain. This phenomenon easily damages large-aperture optical components and threatens the long-term operational stability of the driver. Current mainstream monitoring technologies heavily rely on expensive high-speed oscilloscopes and complex wavelength conversion processes, which not only significantly increases system costs but also limits their feasibility for multi-channel, large-scale deployment in large laser facilities.



Figure 1 : Structure diagram of the Delayed Unlock Modulation Extractor (DUME) module :a) Schematic diagram of the detection module structure; b) Delayed unlocking detection principle

In light of this, researchers have proposed a novel, low-cost, modular FM-to-AM detection architecture that eliminates the need for a high-speed oscilloscope—the Delay-Unlocked Modulation Extractor (DUME) . This system utilizes a high-speed photodetector, a low-noise amplifier, and an envelope detector to map the modulation depth to a voltage signal, and implements a delay-unlocking strategy through dual comparators controlled by a field-programmable gate array (FPGA) . This strategy introduces a hardware delay of approximately 1.3 nanoseconds, actively shielding transient spikes caused by the rapid rise and fall edges of nanosecond laser pulses, ensuring that amplitude is extracted only in the stable region, and adaptively adjusting the threshold dynamically. Experimental results show that, under conditions of a 20 GHz modulation frequency and a pulse rise time of less than 60 ps , this module can reliably measure modulation depths from 1.27% to 19.15% . Facing various complex pulse waveforms, including exponential and pre-pulse types, the system can accurately recover the true modulation depth. The peak-to-valley deviation for square wave pulse measurements is only 2.94% , and the root mean square error is 0.48% , fully meeting the high-precision monitoring requirements of ICF systems. This compact, modular design effectively eliminates the reliance on high-speed oscilloscopes for continuous sampling of traditional high-frequency signals, significantly reducing single-point monitoring costs and providing excellent frequency expansion flexibility . This technology offers a highly promising amplitude-frequency modulation monitoring solution for multi-beam ICF laser drivers .