Efficiency enhancement for Kα x-ray yields from laser-driven relativistic electrons in solids

Phys Rev Lett. 2011 Jun 10;106(23):235002. doi: 10.1103/PhysRevLett.106.235002. Epub 2011 Jun 6.


High-irradiance short-pulse lasers incident on solid density thin foils provide high-energy, picosecond-duration, and monochromatic K(α) x-ray sources, but with limited conversion efficiency ϵ of laser energy into K(α) x-ray energy. A novel two-stage target concept is proposed that utilizes ultrahigh-contrast laser interactions with primary ultrathin foils in order to efficiently generate and transport in large quantities only the most effective K(α)-producing high-energy electrons into secondary x-ray converter foils. Benchmarked simulations with no free numerical parameters indicate an ϵ enhancement greater than tenfold over conventional single targets may be possible.