Plasma Diagnostics with a table-top soft x-ray laser

We discuss the first demonstrations of plasma diagnostics using a tabletop soft x-ray laser. A very compact capillary discharge pumped Ne-like Ar laser operating at 46.9nm was used to perform shadowgraphy and interferometry experiments in discharge-created and laser-created plasmas. A soft x-ray backlighting experiment was conducted to study the evolution of a micro-capillary discharge plasma waveguide. In a second set of experiments we took advantage of the good spatial coherence of the capillary discharge laser to perform soft x-ray interferometry measurements. In a first experiment the laser was used in combination with a simple wavefront division interferometer based on Lloyd's mirror to map the electron density distribution in the cathode region of a pinch discharge. In our most recent experiment we used an amplitude division interferometer, which utilizes diffraction gratings as beam splitters, to probe a large scale (2.7mm long) laser-created plasma. Both interferometer schemes can be adapted to operate at the wavelength corresponding to any of the presently available saturated soft x-ray lasers.