Source of gamma photons in multipetawatt multibeam systems of electric dipole configuration

Abstract: We study the possibility of developing an ultra-high-brightness photon source with energies up to several GeV based on promising multipetawatt multibeam laser systems. For a maximum photon energy to be reached and for a directed photon beam to be generated, use is made of an electric dipole field structure as the main configuration, which maximises the amplitude of the electric field in the focus region. The dependences of the characteristics of the generated gamma radiation on the number of laser beams irradiating the plasma target and their focusing are investigated. It is shown that at the laser system parameters close to the stated XCELS facility parameters and a total power of 36 PW, the maximum energy of gamma-ray photons can reach 2 GeV, the efficiency of conversion of laser radiation into photons with an energy of more than 1 MeV is 40%, and the flux of photons with an energy above 1 GeV may approach 10²⁵ s^–1. The radiation pattern of gamma radiation can be only a few mrad wide and carries information about various regimes of plasma-field dynamics in the focal region. The performed studies show that multibeam multipetawatt laser systems, such as XCELS, can become the basis for constructing an ultra-high-brightness source of gamma radiation.

Keywords: gamma photons, QED cascade, multipetawatt systems, ultra-high-brightness source, XCELS facility, multibeam configurations.