Generation and mitigation of Electromagnetic pulses from laser interacting with foam targets

Abstract High-power laser interacting with solid targets produces intense electromagnetic pulses (EMPs), which are strongly related to target configuration. In this study, EMPs induced by femtosecond (fs) laser irradiating CHO and Ag foam targets are recorded at the XG-III laser facility. Compared to planar targets, foam targets generate much stronger EMP radiation with a peak amplitude of 121.5 kV/m. The resulting EMPs have a broad frequency domain ranging from 0.5 MHz to 2 GHz. High temperature of hot electrons stimulated from foam targets is responsible for the enhanced EMPs. EMP signals recorded inside an aluminium shielding cage are attenuated from 98.1 kV/m to 67.2 kV/m, and the residual signals may stem from ionizing radiation of high-frequency radiations. This work is helpful to deeply understand the EMPs’ generation and establish the basis for EMP shielding within the target chamber.