Investigation of x-ray emission induced by hot electrons in dense Cu plasmas

Spectral lines induced by the action of suprathermal electrons in a laser-irradiated (400 J, 1315 nm, 250 ps, I = 4 × 1016 W cm−2) Cu target were observed. A whole set of transitions between Kα and Heα lines originating from Be-like to Ne-like Cu was identified. The emission was modeled using the Flychk code [1]; the resulting theoretical spectra were integrated over a wide range of bulk plasma temperatures and hot electron fractions to obtain good agreement with the experimental data. The simulation procedure used offers a basis for the development of alternative x-ray spectroscopic diagnostics for hot electrons.