Superradiation from non-ideal plasmas in electric field

An effect of external static electric field on emission of radiation from non-ideal plasmas of erosion focus has been experimentally observed. An order-of-magnitude increase in radiation intensity for spectral interval hv = 40 ? 350 eV with electric field increasing up to 10³V/cm has been found for plasmas with $\text{ξ}\text{Z}\text{?1}$, where ξ is the number of electrons in Debye sphere, Z = 2 ? 3 is the stage of ionization. The energy emitted has been several times higher than the black body energy for the same spectral interval at maximum electric field achieved. The effect vanishes at $\text{ξ}\text{Z}\text{?10}$.