Using spherically bent crystals for obtaining high-resolution,large-field, monochromatic X-ray backlighting imaging for wide range ofBragg angles

摘要

Summary form only given, as follows. The new advantages ofwell-known combination of a laser-produced X-ray plasma source andspherically bent crystal for the soft X-ray region backlighting schemewere experimentally demonstrated and theoretically modelling byray-tracing package SHADOW. The X-ray source was produced by heatingradiation of Ti:sapphire laser (120 fs, 3-5 mJ, laser flux density 10¹³ W/cm²) or XeCl laser (1-1.3 J, 10 ns, laserflux density 10¹³ W/cm²) with repetition 10 Hz atdifferent solid targets (Mg, Fe, Ni, Dy, BaF₂). X-ray sourcespot size on the target was well localised both spatially (~20 μm)and temporally (1 ps-10 ns, depend of used laser) and is spectrallytunable in a relatively wide range (6-19 Å). High qualitymonochromatic (δλ/λ~10^-5-10^-3)images with high spatial resolution (up to ~4 μm) and in a largefield of view (few mm) were obtained for different wavelengths using thesame spherically bent crystal. It was demonstrated at first time thatthe spherically bent crystals can be sufficiently used for obtaininghigh-resolution, large-field, monochromatic images in a wide range ofBragg angles (θ=40-90° ), thus spherically bent crystals areuniversal for very wide wavelength selection, what is very important formany applications. Obtained experimental results were independentlyconfirmed by ray-tracing modelling for different radius of crystalcurvatures, Bragg angles and linear magnification of images