Dynamics of XUV and X-ray radiation spectrum from a 200-ns X-pinch plasma

Summary form only given. X-pinch plasmas are point-like X-ray sources with potential application for backlighting diagnostic in the keV range. A very compact LC generator (40 kV, 200 kA) has been used for driving X-pinches made of 18-25 mum diameter Cu, Mo and W wires with a current rise time of 200 ns. A series of XRD and silicon p-i-n detectors with various filters were used to study their X-ray spectra in the range 20 eV-10 keV. Time resolved spectral analysis allows us to assume some stages of X-pinch process. The first stage deals with plasma load preparation, while XUV radiation spectrum is below 400 eV. Its total radiation power is (5-10)times10⁷ W during ~125 ns before the main peak. It yields a total energy ~5-10 J. Then, 3-5 ns preceding the main peak one can observe plasma heating accompanied by emission increasing in the range 200-400 eV, but without appreciable value in the harder region >400 eV. Here, the total power is about (2-4)times10 ⁸ W. The main peak power is estimated to be a little bit higher than 1 TW with 20-35% in the E>900 eV photon energy range. Its FWHM is 0.4-0.7 ns in the energy region higher than 1 keV. At last, an emission tail with a specific times about 75-100 ns is composed of XUV radiation softer than 400 eV. Here, the radiation power varies at the range (1-4)times10⁸ W. A few humps with FWHW 6-20 ns are very often observed on the radiation tail