Fyzikální ústav Akademie věd ČR

Angular distributions of currents and velocities (energies) of ions produced at various target irradiation angles and laser intensities ranged from 10¹⁰ W/cm² to 10¹⁷ W/cm² were analyzed. It was confirmed that for low laser intensities the ion current distributions are always peaked along the target normal. However, at laser intensities comparable to or higher than 10¹⁴ W/cm², the preferred direction of ion emission strongly depends on the irradiation geometry (laser focus setting, the irradiation angle), and can be off the target normal. This is very likely caused by the non-linear interaction of the laser beam with produced plasma, in particular, by the action of ponderomotive forces and the laser beam self-focusing.

L. Láska, K. Jungwirth, J. Krása, E. Krouský, M. Pfeifer, K. Rohlena, A. Velyhan, J. Ullschmied, S. Gammino, L. Torrisi, J. Badziak, P. Parys, M. Rosinski, L. Ryc, J. Wolowski
Angular distributions of ions emitted from laser plasma produced at various irradiation angles and laser intensities
Laser Part. Beams 26 (2008) 555 - 565, doi: 10.1017/S0263034608000591