国产ECRH 175 GHz兆瓦回旋管实现500 kW/100 s长脉冲输出OA

[Background]Electron cyclotron resonance heating(ECRH)is essential for plasma heating in magnetic confinement fusion,relying on high-power gyrotrons.Advanced fusion projects such as ITER,CFETR,and BEST require large numbers of high-frequency,high-power,long-pulse gyrotrons.Although such devices have been developed internationally,a fusion-compatible long-pulse megawatt gyrotron had not been achieved in China.[Purpose]This letter presents recent experimental results from a 175 GHz long-pulse gyrotron developed at China Academy of Engineering Physics,aiming to validate its design and demonstrate 100 s continuous operation at the hundred-kilowatt level.[Methods]The gyrotron uses a diamond window,operates in the TE28,11 mode,and employs a triode magnetron injection gun and a single-stage depressed collector with vertical sweeping.Power was measured calorimetrically using a water load,and thermal behavior of key components was monitored.Systematic conditioning and parameter tuning extended pulse length progressively.[Results]The gyrotron achieved a stable output of 500 kW for 100 s with 46%total efficiency.Output frequency remained at 175.04 GHz with less than 40 MHz drift.The measured efficiency matches the design expectations,confirming stable device performance.This is China's first hundred-kilowatt-level 100 s ECRH gyrotron operation.[Conclusions]Successful 500 kW/100 s operation validates the gyrotron design and supports its application in domestic fusion devices.Future efforts will upgrade the power supply for megawatt long-pulse operation and conduct joint tests with domestic fusion facilities.