Failure analysis of electron gun of a 10 MeV RF linac

Industrial Electron Linacs have become popular tools for a multitude of radiation technology applications in the fields of material modification, pollution control as well as national security. Although thousands of accelerators are being regularly used, failure analysis of Industrial Electron Accelerators remains a sparsely researched topic and not much information is available in public. Being an economically viable option, industrial electron accelerators need to have a 24 x 7 reliable operation. Hence, it is necessary to understand the failure modes and their mitigation techniques, so that the operation of the accelerators is stable, consistent and safe. In this study, failure mode analysis and identification of degradation mechanisms in an industrial 10 MeV RF electron linac have been studied, with emphasis on the electron gun. Failure modes of the linac and its sub-systems have been investigated. Failure Mode and Effects Analysis and Fault Tree Analysis techniques have been examined for the electron gun. Bayesian Networks are used for modelling the performance of electron gun sub system, utilising the operational data of the RF linac. This approach has facilitated the evidential reasoning process to investigate most probable mode of failure and preventive measures have been recommended for mitigation of failure.