ABSTRACT
Two-dimensional imaging in the wavelength region of the water window (N Ly alpha) is demonstrated with a toroidally curved thallium acid phthalate crystal. Direct imaging of a plasma pinch line, as well as imaging of a mesh with plasma backlighting in which the same source is used, is shown. For verification, the results are compared with the results by other methods. An absolute intensity calibration of the images is demonstrated with theoretical data for the reflection properties of the crystal. This advance in two-dimensional imaging was possible owing to the recent progress in the precise bending of acid phthalate crystals to defined concave shapes of high quality (sphere, toroid). With these crystals, the two-dimensional imaging method is pushed to the wavelength of 2.66 nm, which is well inside the water window.
ABSTRACT
An x-ray imaging system with a bent focusing crystal was used for time-resolved one-dimensional imaging of a long plasma column of highly ionized aluminum. This scheme uses a focusing geometry with a spherically bent crystal and a slit on the Rowland circle. Alternative schemes of x-ray monochromatic imaging are briefly discussed. The homogeneity of the up to 40-mm-long laser-generated plasma column was studied with a temporal resolution of 100 ps. The potential spatial resolution of the instrument is 90 microm or better. Monochromatic images taken on the resonance He alpha line of Al XII characterize the homogeneity of a plasma generated to study a recombination x-ray laser scheme, giving an amplified spontaneous emission in Al XI.
