Attosecond pulse generation via relativistic Thomson scattering in xenon clusters

Interaction of lasers with atomic clusters finds application in various fields. Apart from the production of high energy ions and electrons, the electrons produced during this process also undergo Thomson scattering to emit radiation which can have the same frequency as the incident laser or higher order harmonics of the fundamental frequency of the laser. When the intensity of the laser beam interacting with a cluster exceeds 10¹⁸ W/cm², the interaction becomes relativistic. The electrons produced undergo non-linear Thomson scattering and not only produce higher harmonics spectra, but also produce high energy bursts of attosecond duration. Firstly, the laser ionizes a neutral cluster as a result of which electrons are produced which emit radiation. Presence of ions also causes the electrons to experience coulombic forces. Also, the laser effectively interacts with electrons at rest as compared to a counter-propagating laser-electron beam interaction. Thus, the ponderomotive force of laser drags the electrons along with the pulse. These factors facilitate the emission of high energy bursts of attosecond duration. In this study we have explored the possibility of production of attosecond pulses using interaction of short, intense laser beams with Xenon clusters. We have used the 3D molecular dynamics technique to simulate the interaction of femtosecond laser pulses with Xenon clusters and try to optimize the production of single attosecond pulses of high energy. (author)