ИСТИНА

The development of high power laser systems capable of delivering ultra-relativistic laser pulses of femtosecond duration led to the whole new area of investigation of particle motion and its acceleration directly by the field of the laser radiation. The complex non-Gaussian spatial and temporal profile of the pulse results in generation of electron with high residual energy. The interaction between tightly focused laser radiation and an electron is determined by a peculiar topology of the laser field in the tight focus. As a result direct electron acceleration has a unique spectral characteristic that is why these spectra are suitable to estimate the peak laser intensity [1,2]. Thus, the study of the spectral and angular characteristics of the particles, emitted from the high intensity region (focal area) of the pulse, may be utilized to reconstruct the basic parameters of the initial radiation – peak intensity and transverse energy distribution. In this work we present our recent experimental and numerical achievements in the investigation of the particles dynamics under the action of relativistically strong femtosecond laser radiation.