In experiments on irradiation of metal surfaces by ions of keV energy, the emission of X-ray laser beams from the metal was observed not only during irradiation but also 20 h after it was switched off (from the “dead” sample). In contrast to a usual laser, the emitted collimated X-ray beams were of continuous frequency. In this paper the mechanism of that phenomenon is proposed. Subatomic electron states are formed inside the metal. These states are associated with anomalous wells within the subatomically small (10−11 cm) region. An anomalous well is formed by the local reduction (of MeV scale) in that region of zero point electromagnetic energy. States in anomalous wells are long-lived, which results in population inversion and the subsequent laser generation observed. The energies of emitted X-ray beams are due to the conversion of zero point electromagnetic energy (X-ray laser beams from vacuum).
Population inversion and gain measurements for soft X-ray laser development in a magnetically confined plasma column