Аннотация:We report efficient (∼10–4) generation of terahertz (THz) radiation under relativistic laserirradiation of nitrogen and oxygen gas-cluster targets. The relationship between the THz radiationyield and the process of laser-plasma generation of a megaelectronvolt electron beam, the diver-gence of which depends on the target density, is established. For a femtosecond laser beam inten-sity of ∼1019 W/cm2, an energy of 20 μJ is recorded in the frequency range from 0.1 to 3 THz at anaccelerated electron bunch charge of nanocoulomb units. Directionality and polarization of the THzpulse, as well as the dependence of its energy on the gas type, pressure, power, and duration of thepump pulse, are measured.
