[en] The AIRIX accelerator is used to realize flash radiography during hydro-test experiments. We have developed a tool to monitor the functioning state of this facility. This procedure is based first on signal processing and data mining. It allows to select the most important parameters to characterize the functioning state. A pattern recognition strategy realizes the identification of the functioning state. We propose an original algorithm to construct and initialize a radial basis function neural network with experimental data, and to take into account new states which could appear. The objective is to detect transient states before failure. (authors)

[en] Airix is a linear accelerator producing a 60 ns, 2 kA, 19 MeV electron beam. It has been operated in a single shot mode by the 'Commissariat a l'Energie Atomique et aux Energies Alternatives' (CEA) for flash X-ray radiography purposes for nearly 12 years. Usually each accelerating unit (a cell and its driver) delivers a 100 ns pulse of 250 kV amplitude to the beam. The test bench is used to determine the behaviour over time of the cells, the driver (high voltage generator) and the links between them (high voltage cables). We try different configurations and deal with ensuing problems. In this paper, we describe the test-bed in use, the problems we have met and how we dealt with them, and we establish the reliability performances we now expect from the accelerating units for the next decades. (authors)

[en] Radiography is an imaging technique capable to reveal information about internal structure of an object which is opaque to the visible light. It relies on the analysis of the different X-ray flux attenuations through an object under investigation. X-ray must be energetic enough to go through the object. Attenuation differences induce a contrast on the detector and form an image. According to the experimental requirements in terms of time resolution (static or fast moving object), X-ray pulse duration or gated time on the detector are adjusted. High pulsed power driver with their specific ability to deliver very short pulse have enable the development of X-ray flash radiography systems. Historically, the first X-ray flash radiographic machines had been developing for years by coupling a pulse power generator with a radiographic diode (generator + diode system). For those systems, X-ray photon energy (keV or MeV) is driven by the operational voltage of the pulse power machine (kV or MV). As a consequence, for this technology, breakdown voltage of insulating materials gives the upper limit of the photon energy. An alternative was found over time to reach higher energy levels. Looking at the AIRIX example, the interest of this approach is highlighted. Basically, there is no more need for having the so-called galvanic voltage inside the generator to set the photon end point energy. Instead, accelerating voltage is distributed all along the machine and supplied by small high voltage generator. The electron beam is natively emitted in an injector which operates at a relatively low voltage and which much lower current intensity comparatively to a generator + diode approach. (authors)