SPring-8 Angstrom Compact free-electron LAser (SACLA) at SPring-8, Japan [1,2] was inaugurated in March, 2012 as the first compact XFEL facility that combines a low-emittance electron-beam injector, a high-gradient C-band linac, and short-period in-vacuum undulators. SACLA generates intense short-wavelength XFEL radiation below 1 Å with a moderate electron beam energy of 8 GeV. To extend capabilities, state-of-the-art X-ray optic, detectors, and experimental instruments have been continu-ously developed.
To further increase an intensity of XFEL pulses, we have developed a 1-um focusing optics [3] and a 50-nm focusing optics based on a two-stage scheme [4], by using state-of-the-art reflective mirrors in a collaboration with Osaka University. A significant intensity of 10^20 W/cm2 generated by the tight fo-cusing system has enabled unique opportunities for conducting non-linear X-ray sciences, for example, atomic K-alpha lasers excited with XFEL pulses [5], two-photon X-ray absorption [6], and X-ray-pump & X-ray-probe studies to investigate ultrafast damage processes induced by intense X-rays [7].
In this talk, I will review the status [8] and future perspective of the complex facilities SACLA and SPring-8.
References
[1] T. Ishikawa et al., Nature Photon., 6, 540 (2012).
[2] M. Yabashi et al., J. Synchrotron Rad., 22, 477 (2015).
[3] K. Yumoto et al., Nature Photon., 7, 43 (2013).
[4] H. Mimura et al., Nature Commun., 5, 3539 (2014).
[5] H. Yoneda et al., Nature, 524, 446-449 (2015).
[6] K. Tamasaku et al., Nature Photon. 8, 313 (2014).
[7] I. Inoue et al., Proc. Natl. Acad. Sci. USA. 113, 1492 (2016).
[8] http://xfel.riken.jp/research/indexnn.html
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