ABSTRACT
We report direct measurement of the electromagnetic-field spatial distribution in a neonlike Ar capillary discharge-driven soft x-ray laser beam. The wave front was fully characterized in a single shot using a Shack-Hartmann diffractive optics sensor. The wave front was observed to be dependent on the discharge pressure and capillary length, as a result of beam refraction variations in the capillary plasma. The results predict approximately 70% of the laser beam energy can be focused into an area 4 times the size of the diffraction-limited spot, reaching intensities of approximately 4 x 10(13) W/cm(2).
ABSTRACT
The development of third-generation synchrotron sources has stimulated efforts toward high-resolution monochromators. A good knowledge of grating efficiency is needed to achieve an optimal compromise between resolution and photon flux. Because simple geometric models fail to describe correctly the gratings properties in the UVtosoft-X-ray range, we have developed a simulation software based on differential theory. A simplified R-matrix propagation algorithm assures the numerical stability of the code for deep gratings. Our numerical results are compared with previous research on deep gratings. Experimental and numerical studies have been performed on some test cases at a synchrotron source. Very good agreement between numerical prediction and measurement has been found.
ABSTRACT
We demonstrate how to use a cylindrical Bragg-Fresnel multilayer focusing system instead of spherical mirrors for two-dimensional focalization. We performed our tests at 8 keV with a collimated x-ray tube having an apparent anode source size of 75 microm x 100 microm. These tests demonstrate that focalization can be obtained within <20 microm. This offers new possibilities in optical systems for collimators and fine focusing of x-rays, especially for synchrotron radiation sources.
ABSTRACT
We describe under which conditions the x-ray energy dispersive method permits absolute reflectivity, energy band pass, and overlapping order determination on artificial multilayers. For such measurements a Si (Li) detector and a simple x-ray tube are used. Examples of experimental results on W/Si and Mo/Si x-ray mirrors are given for the photon energy range from 5 to 40 KeV.
