Speaker: Jakub Cikhardt (Czech Technical University)

The interaction of a focused high-power laser with matter results in the generation of an electromagnetic pulse (EMP). In the case of terawatt and petawatt lasers, the intensity of the EMP is strong enough to interfere with diagnostic signals and may cause malfunction or distortion of electronic devices. Moreover, the laser-driven EMP could cause problems in experimental basic research, inertial nuclear fusion, laser-plasma biomedicine and other high-power laser technologies. On the other hand, the mechanisms of this phenomenon are not fully understood, making it an interesting topic for the fundamental physics of laser-matter interaction. Therefore, the laser-driven EMP is intensively studied at the PALS laser facility – a joint research infrastructure of the Institute of Plasma Physics and the Institute of Physics of the Czech Academy of Sciences in cooperation with other world-leading institutions such as the Univ. of Bordeaux, CLF Rutherford Appleton Laboratory, CLPU Salamanca, ENEA C.R. Frascati, and others.

In recent years we have achieved some interesting results, such as

• the observation of unprecedentedly broad EMP bandwidths;
• the dependence of the EMP spectrum shape and upper cut-off frequency on the laser beam energy/power, target material and target ground impedance;
• the relation between EMP emission and the escaped electron energy spectrum;
• the influence of the wave plate on the emission of charged particles and EMP; and
• the characterization of the EMP caused by laser interaction with various gas targets.

As part of this research, a number of EMP diagnostics have been developed, such as inductive target current probes, high-voltage target probes and B-dot arrays, and electro-optical probes have been tested. We believe that this research will contribute to EMP mitigation, will enrich fundamental physics knowledge, and will also lead to numerous high-tech applications, such as electromagnetic compatibility hardening, biology and defense.