Monitoring Procedure of a Complex Facility, Example of High Voltage Generators Analysis

Abstract

The AIRIX 1 facility is a high current linear accelerator used for flash-radiography at the CEA of Moronvilliers (France)[1] [2]. This accelerator has been designed to generate an intense X-ray pulse of 500rads at 1m, using a 2kA, 20MeV, 60ns electron beam. This beam is created by an injector that delivers a 2kA, 3,5 to 3,8MeV, 60ns electron beam, and 64 induction cells powered by 32 high voltage generators. Each of this cells adds 250keV to the beam. After each trial, the signals picked up are checked to determine local problems. Our aim is to highlight the slow drifts of the performances of the facility which are not directly observable by the operators. We concentrate first on the high voltage generators to build our analysis. The final objective of our study is to develop signal processing tools for predictive maintenance of the whole AIRIX induction accelerator. We have set up a monitoring procedure based on two complementary methodologies. In the first one, relevant features are extracted from electrical signals of the facility, and statistical analysis are made on them. Results should improve the understanding of the functioning of the facility. The second one is based on a global analysis of the signal. We detect in the time-frequency plane the place of signal evolutions between two periods, making the analysis easier for the operators.