TIME-DEPENDENCE OF THE SPATIAL COHERENCE OF THE 23.6 AND 23.2-NM RADIATION FROM THE GERMANIUM SOFT-X-RAY LASER

The time dependence of the spatial coherence of the combined spectral lines at 23.2 and 23.6 nm from the Ge XXIII collisionally pumped soft- x-ray laser with a double-slab target is examined within a single nano second pulse by use of Young's interference fringes and a streak camer a. High source intensity is linked with low spatial coherence and vice verse. Calculations of the source intensity, size, and position have also been made; these calculations refer to a single-slab source. Comp arison between the observed and calculated intensities, and of the sou rce sizes both calculated and derived from the Young's fringes by inte rpretation with a Gaussian model of source emission, show good agreeme nt in general trends. (C) 1998 Optical Society of America [S0740-3224( 98)01905-5].