(Color online) Drawing describing the experimental detection geometry with the x-ray source-grating-detector positions. On the target the incident laser beam at is polarized. The light tight filter (aluminum) which delimits the spectrometer entrance and the debris protection filter (parylene) used in the experiments are shown. For time resolved experiments, the sample laser excited area (pump beam) and the corresponding area on the detector are shown.
(Color online) Illustration of the sample geometry used during the experiments. On the left to get both the measured transmission spectrum of the sample of interest (the rectangle represent the membrane with the layer of interest on the top of it and corresponds to condition 1) and the x-ray emission reference spectrum (empty window corresponding to the white rectangle) for high quality static XANES spectrum measurement. On the right to get both the laser excited sample transmission spectrum (condition 2: membrane window with laser excitation) and the reference transmission spectrum with no excitation (condition 1). Typically the windows are made with the help of layer on top of a Si wafer and then chemically etched. For example, for time resolved studies of , this material is deposited on the top of the layer before the etching process.
(Color online) Raw measured transmission spectrum with a tantalum solid target and a polyimide sample. No parylene filter was used. The time accumulation to get this picture was at repetition rate. The horizontal axis corresponds to the energy axis. From the left of the image, the characteristics features are an oxygen emission line, the oxygen edge, the nitrogen edge, and the carbon edge.
(Color online) Absorbance XANES spectrum of a thin film near the vanadium edge and the oxygen edge with signal accumulation.
(Color online) Absorbance XANES spectrum of a thin film near the nitrogen edge with signal accumulation.
(Color online) Transmittance XANES spectrum of a polyimide film near the carbon edge with signal accumulation.
Laser based x-ray source performance at several characteristic energies: number of photons measured with shot accumulation, corresponding signal to noise ratio (SNR), time accumulation needed for 1% SNR, and brightness of the x-ray source.
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