Observation and theory of X-ray mirages

Magnitskiy, S.*; Nagorskiy, N.*; Faenov, A.*; Pikuz, T.; Tanaka, Momoko; Ishino, Masahiko; Nishikino, Masaharu; Fukuda, Yuji; Kando, Masaki; Kawachi, Tetsuya; et al.

Nature Communications (Internet), 4, p.1936_1 - 1936_7, 2013/06

https://doi.org/10.1038/ncomms2923

Advent of plasma-based transient collisional excitation X-ray lasers allowed us to realize compact coherent X-ray sources, thus opening the way to a wide range of applications. Here we report the observation of unexpected concentric rings in the far-field beam profile at the output of a two-stage plasma-based X-ray laser developed in Japan Atomic Energy Agency, which can be considered as the first manifestation of a mirage phenomenon in X-rays. We have developed a method of solving the Maxwell-Bloch equations, which has allowed to find that the observed phenomenon is due to the emergence in the plasma-amplifier of X-ray mirage in the form of the phase matched coherent virtual point source. The obtained results bring a new insight into physical nature of amplification of X-ray radiation in laser-induced plasma amplifiers and open new opportunities for X-ray plasma diagnostics and extreme UV lithography.

Progress and prospects of coherent X-ray research using high power lasers in JAEA

Kawachi, Tetsuya; Nishikino, Masaharu; Sasaki, Akira; Ishino, Masahiko; Hasegawa, Noboru; Imazono, Takashi; Pikuz, T.; Faenov, A. Ya.*; Magnitskiy, S.*; Maruyama, Momoko; et al.

no journal, , 

Laser-driven X-ray sources are widely used in probing substances for new material development etc. Besides the laser-driven sources have potentials to downsizing and ultra-short duration, we carry out the coherent X-ray research, i.e., soft X-ray lasers and higher order harmonics generation (HHG) and their applications. In the source study, the first observation of X-ray mirage and HHG from relativistic plasma are presented. In the applications, we show the surface dynamics of fs laser ablation of metal observed by the X-ray interferometer. Finally we mention the prospects for the future: By the financial support from government, we started upgrade of J-KAREN laser toward PW level to realize keV coherent X-ray and high energy particle beams. By use of this high peak power laser and another high average power lasers, we will explore the possibility of ultra-short-duration short-wavelength lasers and open up new applications of high average power coherent X-rays.

Phase-matched coherent point source generation in plasma media by propagated X-ray laser seeded beam

Nagorskiy, N.*; Magnitskiy, S.*; Pikuz, T.; Faenov, A.*; Tanaka, Momoko; Ishino, Masahiko; Nishikino, Masaharu; Fukuda, Yuji; Kando, Masaki; Kato, Yoshiaki*; et al.

no journal, ,