Nonlinear coherent Thomson scattering from relativistic electron sheets as a means to produce isolated ultrabright attosecond x-ray pulses

• Main Authors: H.-C. Wu (武慧春), J. Meyer-ter-Vehn, B. M. Hegelich, J. C. Fernández
• Format: Article
• Language: English
• Published: American Physical Society 2011-07-01
• Series: Physical Review Special Topics. Accelerators and Beams
• Online Access: http://doi.org/10.1103/PhysRevSTAB.14.070702

A new way to generate intense attosecond x-ray pulses is discussed. It relies on coherent Thomson scattering (CTS) from relativistic electron sheets. A double layer technique is used to generate planar solid-density sheets of monochromatic high-γ electrons with zero transverse momentum such that coherently backscattered light is frequency upshifted by factors up to 4γ^{2}. Here previous work [H.-C. Wu et al., Phys. Rev. Lett. 104, 234801 (2010)PRLTAO0031-900710.1103/PhysRevLett.104.234801] is extended to the regime of high-intensity probe light with normalized amplitude a_{0}>1 leading to nonlinear CTS effects such as pulse contraction and steepening. The results are derived both by particle-in-cell (PIC) simulation in a boosted frame and by analytic theory. PIC simulation shows that powerful x-ray pulses (1 keV, <10   attosecond, and >10   gigawatt) can be generated. They call for experimental verification. Required prerequisites such as manufacture of nanometer-thick target foils is ready and ultrahigh contrast laser pulses should be within reach in the near future.