A soft X-ray free-electron laser beamline at SACLA: the light source, photon beamline and experimental station.

Shigeki Owada,Yasumasa Joti,Tadashi Togashi,Makina Yabashi,Takashi Tanaka,Yasunori Senba,Kyo Nakajima,Hitoshi Tanaka,Haruhiko Ohashi,Tetsuya Ishikawa,Mitsuhiro Yamaga,Hirokatsu Yumoto,Takahisa Koyama,Kensuke Tono,Kazuaki Togawa,Takahiro Inagaki,Toru Hara

doi:10.1107/s1600577517015685

Abstract

The design and performance of a soft X-ray free-electron laser (FEL) beamline of the SPring-8 Compact free-electron LAser (SACLA) are described. The SPring-8 Compact SASE Source test accelerator, a prototype machine of SACLA, was relocated to the SACLA undulator hall for dedicated use for the soft X-ray FEL beamline. Since the accelerator is operated independently of the SACLA main linac that drives the two hard X-ray beamlines, it is possible to produce both soft and hard X-ray FEL simultaneously. The FEL pulse energy reached 110 µJ at a wavelength of 12.4 nm (i.e. photon energy of 100 eV) with an electron beam energy of 780 MeV.

Highlights

The advent of X-ray free-electron lasers (XFELs) has stimulated marked progress in various scientific fields, such as ultrafast chemistry (Moshammer et al, 2007; Erk et al, 2014), nonlinear X-ray optics (Rohringer et al, 2012; Glover et al, 2012; Bencivenga et al, 2015) and structural biology (Boutet et al, 2012; Nango et al, 2016)
The first FEL operation in the extreme ultraviolet (EUV) region was achieved by the TESLA Test Facility (TTF; Andruszkow et al, 2000) at DESY, Germany, in 2000, which was later renamed FLASH (Ackermann et al, 2007)
The FEL wavelengths were shortened to the angstrom region by the Linac Coherent Light Source (LCLS) (Emma et al, 2010) at the SLAC National Accelerator Laboratory (SLAC), USA, in 2009

Summary

Introduction

The advent of X-ray free-electron lasers (XFELs) has stimulated marked progress in various scientific fields, such as ultrafast chemistry (Moshammer et al, 2007; Erk et al, 2014), nonlinear X-ray optics (Rohringer et al, 2012; Glover et al, 2012; Bencivenga et al, 2015) and structural biology (Boutet et al, 2012; Nango et al, 2016). The SPring-8 Angstrom Compact free-electron LAser (SACLA), constructed in Harima, Japan, achieved first lasing at 10 keV in June 2011 and started operation for users in March 2012 with two beamlines: BL3 for a hard X-ray FEL, which is capable of generating the shortest wavelength FEL below 0.8 A , and BL1 for wide range spontaneous emission (Ishikawa et al, 2012; Yabashi et al, 2015). The first high-harmonic-generation (HHG) seeded FELs in the ultraviolet (UV) and EUV region were demonstrated (Lambert et al, 2008; Togashi et al, 2011; Tomizawa et al, 2015) After these achievements and successful operation of SACLA, the SCSS was decommissioned in 2013. Undulator Periodic length Number of undulator modules Total number of period Maximum K Minimum gap Averaged betatron function, x/ y

Light source

Beamline

Experimental station

Findings

Conclusion and perspective