Induced transitions in a continuous spectrum and the possibility of radiation amplification

The paper presents a theoretical assessment of the feasibility of the amplification of electromagnetic radiation during the induced photorecombination of an electron into the rapidly decaying autoionization state of a negative ion. A relatively high gain value is obtained for a relatively low density of the amplifying medium, which indicates that the proposed scheme of transitions can be used effectively for the amplification of short-wave radiation in a wide frequency range. It is noted that the proposed scheme can also be used for the efficient absorption of intense radiation and for plasma heating.