A remote detection method for leak location of external ports in a tokamak: Theory and preliminary experimental validation

The vacuum vessel of fusion devices, equipped with an array of external ports characterized by intricate flange connections and welding joints, inherently carries a notable risk of leakage. With the impending introduction of deuterium-tritium fusion reactions, restrictions on technician access necessitate a more innovative approach. This paper introduces a groundbreaking leak detection method for fusion device ports, leveraging the differential pumping effects of molecular screens. A robotic arm is utilized to transport a mass spectrometer equipped with a molecular screen into the tokamak for detecting leaks at external ports. Through theoretical calculations, simulations, and proof-of-principle experiments, our method demonstrates the feasibility in detecting and localizing leaks, offering a promising solution for leak detection in tritium-operated fusion devices.