Thermal and Structural Analysis of a Fully Integrated Space Traveling Wave Tube

Most of the failures occurring in a traveling wave tube (TWT) are related to thermal and structural issues. Hence, it is very important to critically analyze the thermal and structural aspects under extreme operating conditions to ensure the reliability of space TWTs. It has been a general practice to study the thermal and structural performance of individual sub-assemblies of the TWT, namely the electron gun, coaxial couplers, slow wave structure (SWS), and multistage depressed collector. However, the practical results from the fully integrated tube differ from the results of thermal analyses of individual sub-assemblies by approximately 30%. The main reason behind this discrepancy is due to the elimination of interdependencies between the sub-assemblies, which is completely ignored in the sub-assembly level analyses, and the difference in the boundary conditions. Hence, it is essential to perform the thermal and structural analysis of the entire TWT as a whole instead of individual sub-assemblies. In this article, the authors systematically performed the thermal and structural analysis of a fully integrated tube under actual operating conditions and validated the results with a very close agreement with the experimental results. From the simulation results, it can be observed that the results of the fully integrated tube are in close agreement with the experimentally measured temperature values as opposed to the sub-assembly level simulations.