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 3s – 3p transition in multiply charged ions with a ground electronic configuration 1s²2s²2p⁶. 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).