Optical generation of quasistationary plasma electromagnetic structures for particle collimation with petawatt picosecond lasers

Optical generation of energetic particle bunches requires high-power laser facilities operating in picosecond or femtosecond temporal domain. It is therefore preferable to use also short laser pulses in all-optical platforms providing quasistationary electromagnetic fields for guiding and focusing of such particle beams, increasing their brightness and decreasing their angular divergence. In this work, theoretical and experimental results are discussed for a novel electromagnetic guiding setup based on a shaped spiral-like "snail" target with a relatively large focusing aperture in comparison with the previous studies. Due to the diameter increased to a submillimeter scale, wider particle bunches may be efficiently focused, as shown with theoretical modeling using the field distributions, consistent with the presented experimental data.