Saturated amplification of a collisionally pumped optical-field-ionization soft X-ray laser at 41.8 nm.

We report the first saturated amplification of an optical-field-ionization soft x-ray laser. The amplifying medium is generated by focusing a circularly polarized 330-mJ, 35-fs, 10-Hz Ti:sapphire laser system in a few-mm cell filled with xenon. A gain of 67 cm(-1) on the 4d(9)5p-4d(9)5d transition at 41.

High-resolution x-ray imaging of extended lasing plasmas.

An x-ray imaging system with a bent focusing crystal was used for time-resolved one-dimensional imaging of a long plasma column of highly ionized aluminum. This scheme uses a focusing geometry with a spherically bent crystal and a slit on the Rowland circle. Alternative schemes of x-ray monochromatic imaging are briefly discussed.