Ultrasensitive Leak Detection in the Production of Space Traveling Wave Tubes by Quadrupole Mass Spectrometer

It is low leak rate that is a necessary condition for the high reliability and longevity of space traveling wave tubes(Space TWTs).This paper develop an ultrasensitive leak detection method in the production of Space TWTs by quad-rupole mass spectrometer to solve the problem of small leaks being blocked.The reliability of leak detection is tested and verified through a reference leak of 1.8×10^-8Pa·m³/s and a leaking space traveling wave tube.The results show that the lower limit of leak detection under accumulation and under dynamic mode are 1.9×10^-14Pa·m³/s and 8.3×10^-12Pa·m³/s re-spectively.The ultrasensitive leak detection method in the production process can effectively detect the leaks exposed after baking,including leaks that are easy to be blocked in the atmosphere,leaks caused by defective material or weld,etc.