ABSTRACT
Diffraction patterns on the shadow edges of crossed-wires and on an X-UV mirror edge were observed on the footprint of the 21.2 nm, Zn Ne-like X-ray laser beam. We used those patterns to calculate the XRL transverse coherence length at a distance of about 50 cm from the plasma at the center and on the side of the beam. We found that the value of that length changes across the XRL beam. The originality of this approach leads in simply using the half screen diffraction of the X-ray laser beam in the Fresnel range, instead of interference from the multiple Young slits. It allows us to have an idea of the contributions of the mutual and the proper coherence lengths by putting the half screen close enough (few mm) to the plasma.
