Observation of a saturated capillary discharge soft x-ray laser in a 450 mm long alumina capillary

We report a gain saturation in capillary discharge Ne-like Ar 46.9nm soft x-ray laser in an alumina capillary with the length of 450mm. A Ne-like Ar 46.9nm soft x-ray laser with a gain coefficient of 0.55 cm
^-1
and maxima gain product 23.7 is achieved, while the peak of main current is as low as 17.3 kA and the optimum Ar initial pressure in capillary is about 21pa.