FLASH X-RAY RADIOGRAPHY OF ARGON JETS IN AMBIENT AIR

This paper describes the development and application of a soft x-ray f lash radiography technique. A very compact soft x-ray flash source has been specially designed for these studies. The table-top x-ray source developed in this work emits strong doses, up to one roentgen at the output window, of x-ray photons, with most of them in the characterist ic lines of the anode material (photon energy in the energy range 5-10 keV), in pulse of 20 ns FWHM with an x-ray emission zone smaller than 300 mu m. All these characteristics make this source attractive for t he x-ray radiography of high-speed phenomena, down to ten nanoseconds duration and/or for the media presenting weak absorption for the harde r x-ray photons emitted by more conventional flash x-ray systems. Argo n streams in ambient air were chosen as a typical case to enlighten th e potentialities of this method. Single-shot radiographs of such an ar gon jet through rectangular nozzles were obtained. No attempt of quant itative measurement of local density in the argon stream has yet been performed, only the qualitative structure of the jet has been investig ated. Nevertheless, these preliminary results enable us to state that the diagnostics of gaseous or plasma media, even at rather low pressur es, can proceed using soft x-ray flash radiography.