Vacuum Degassing of Parts in Development of Gain and Phase Matched (CW) Mini Helix TWT

Abstract

Vacuum degassing of the components and prototypes (operating in cw mode) of gain & phase matched miniature helix TWT becomes more stringent and critical as heavy gas load is generated during RF-testing of the tube which may affect its performance adversely. These tubes require ultimate vacuum in the range of 10-7 to 10-8 torr, which is not possible without through degassing of the components in the vacuum at different stages of assembly. This paper high lights the different stages of vacuum degassing of parts, components, sub-assemblies etc. in the process of the development and testing of G & P matched (CW) mini helix TWT. In addition to above the vacuum processing of the tantalum sheet to make it suitable for fabrication of components by deep drawing has been presented in this paper.