International Conference "Ultrafast Optical Phenomena" (UltrafastLight-2022), October 03-07, 2022, Moscow
Laser physics and laser optics

Spectra of optical harmonics 2 and 3/2 at subrelativistic laser-plasma generation of X-ray radiation

M. V. Chashchin^a, P. A. Shcheglov^a, A. A. Tausenev^ab, M. M. Nazarov^a, V. M. Gordienko<sup>b

a</sup> National Research Centre "Kurchatov Institute", 123182 Moscow, Russia
^b Lomonosov Moscow State University, 119234 Moscow, Russia

Abstract: The dependence of the visible spectrum (harmonics 2 and 3/2) and the output of $\mathrm{Cu}K_\alpha$ X-ray radiation on the energy and duration of subrelativistic intensity femtosecond laser pulse acting on a copper foil is investigated. It was found that for secondary radiation, the determining factor is the energy density, and not the intensity and duration of the pulse. The power-law dependencies of the secondary output radiation on the duration and the pulse energy have a significantly different indicator. The tendencies of changing the shape of the spectrum for regions dominated by various mechanisms of plasma heating are revealed.

Keywords: X-ray, second harmonic, harmonic three halves, energy density.

Received: 02.12.2022
Revised: 16.01.2023
Accepted: 28.01.2023

DOI: 10.21883/OS.2023.02.55003.19-23

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