A saturated nickel-like samarium x-ray laser beam at 7 nanometers has
been demonstrated with an output energy of 0.3 millijoule in 50-picose
cond pulses, demonstrating that saturated operation of a laser at wave
lengths shorter than 10 nanometers can be achieved. The narrow diverge
nce, short wavelength, short pulse duration, high efficiency, and high
brightness of this samarium laser make it an ideal candidate for many
x-ray laser applications.