The SPring-8 Angstrom Compact free electron LAser (SACLA) - Japanese XFEL facility

A new X-ray free electron laser facility at the SPring-8 campus in Harima, Japan, has started its user run. This is the world's second XFEL facility in the hard X-ray region after the LCLS at Stanford, USA. One of the most important properties of this new Japanese facility is the short wavelength of the X-ray photon; the shortest wavelength attained is 0.634 Å (63.4 pm), which is almost half that achieved at Stanford. The facility uses a 400m linear accelerator as well as a short-gap and very long undulator (periodic length 18mm, minimum gap 3.5 mm, total number of periods 4,986). The maximum power exceeds 10 GW with a pulse duration of 10-14 s. For more information, see the paper, "A compact X-ray free-electron laser emitting in the sub-angstrom region", T. Ishikawa et al., Nature Photonics, 6, 540 (2012). Also visit the Web page, http://xfel.riken.jp/eng/