Simultaneous flash x-ray induced fluorescence imaging and radiography of argon jets in ambient air

This paper describes the development and application of a new x-ray based d iagnostic technique. A compact flash x-ray source emitting 20 ns pulses of around 8 to 10 keV x-ray photons is used to induce the fluorescence of argo n jets in ambient air. This x-ray induced fluorescence (XIF) is then collec ted for imaging experiments. In these preliminary studies, the feasibility of the XIF imaging technique is demonstrated by the characterization of arg on flows in ambient air. The fluorescence of nitrogen molecules, resulting from the x-ray excitation of argon jets and successive energy transfers, is imaged on an intensified linear array CCD detector. The recording of the U V nitrogen fluorescence in our experimental conditions, pulsed excitation a nd atmospheric pressure, is shown to be an efficient and conclusive method for the characterization of argon flow in ambient air. The propagation path s of two converging argon jets are described and the divergence of each of the two jets expanding through a rectangular nozzle is measured. The reliab ility of the XIF imaging technique is successfully confirmed by a compariso n with data obtained using the x-ray radiography technique. The simultaneou s performance of XIF imaging and radiography for the diagnostics of one gas eous flow is achieved in this work. Some future improvements of both techni ques are proposed for their application in other experiments.