Gain in the far vacuum ultraviolet region due to transitions in multiply charged ions

It is shown that a gain of the order of 10–25 cm –1 can be obtained in the 300–700 Å range due to the 3 s – 3 p transition in multiply charged ions with a ground electronic configuration 1 s 2 2 s 2 2 p 6 . This gain may be obtained as a result of heating of electrons in a plasma by high-power ultrashort light pulses (two-stage plasma heating).