Stability analysis of the RF linac based on an AR model

We are pursing operational stability of the RF linac with a method of system analysis. The RF phase and the power for the pre-buncher have been measured, together with environmental parameters including temperatures of the main components, the room temperatures and the AC line voltage. The measured data have been analyzed with the autoregressive model, and the feedback structure of the system has been derived from noise contribution ratios and impulse responses analysis. It was found that the AC line voltage and the temperatures of the klystron room significantly affected operational stability of the linac.