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In order to quantitatively analyze the high-precision traveling wave tube (TWT) electron gun anode welding micro deformation during the process of pulse laser beam welding (LBW), and meeting the terahertz electron vacuum device concentricity design requirements, the welding process of actual anode(Mo1) and anode positioning part(4J33) were studied. Eight LBW spots were pre positioned in the circumferential direction, then four symmetrically and uniformly sections were welded for reinforcement. Detection and compensation were carried out during and after welding. After considering the fit clearance, geometric measurement uncertainty, spot positioning accuracy and welding efficiency, a set of high-precision LBW deformation detection and compensation system was developed . The results showed that the concentricity of anode hole and gun end cover was better than 10μm; the eccentricity caused by the first two LBW joints was larger, about 5-10 μm; the deformation caused by the third spot was 2-4 μm, and that of the next 4-8 spots was less than 2 μm. After 8 spots were pre positioned, the deformation caused by the following four sections was less than 2 μm. After high-temperature baking at 550 °C for 72 hours, the deformation was less than 3 μm. The tensile strength of the weld could reach to 13.2N, which could ensure the anode parts which only weigh 2g could withstand enough mechanical acceleration impact. Compared with the one-time welding four sections, the concentricity was optimized by 60%, and the deformation of high-temperature baking was optimized by 50%.
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