Formation of a Strong Quasi-Static Electric Field under Irradiation of a Target with a Spherical Microcavity by Intense Laser Pulses

The collapse of a spherical microcavity in a plasma target under symmetrical irradiation by intense laser pulses has been numerically investigated. Configurations with 2, 4, and 8 laser pulses are considered. The formation of a strong quasi-static electric field at the cavity center as a result of the collapse is demonstrated. It is shown that the 8-pulse configuration is optimal from the point of view of increasing the ion density in the central bunch and increasing the electric field amplitude, while the transition from the 2-pulse to the 8-pulse configuration increases the field amplitude by a factor of 1.5, preserving the total laser pulse energy. Estimates show that, for the XCELS parameters in the 8-pulse configuration, one would expect the maximum electric field amplitude of 1.61 × 10 14 V/cm, or 1.2% of the Schwinger field.