Arrival timing diagnostics at a soft X-ray free-electron laser beamline of SACLA BL1

An arrival timing monitor for the soft X-ray free-electron laser (XFEL) beamline of SACLA BL1 has been developed. A small portion of the soft XFEL pulse is branched using the wavefront-splitting method. The branched FEL pulse is one-dimensionally focused onto a GaAs wafer to induce a transient reflectivity change. The beam branching method enables the simultaneous operation of the arrival timing diagnostics and experiments. The temporal resolution evaluated from the imaging system is ∼22 fs in full width at half-maximum, which is sufficient considering the temporal durations of the soft XFEL and the optical laser pulses.

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Single-shot arrival timing diagnostics for a soft X-ray free-electron laser beamline at SACLA

Journal of Synchrotron Radiation ◽

10.1107/s1600577517015284 ◽

2018 ◽

Vol 25 (1) ◽

pp. 68-71 ◽

Cited By ~ 8

Author(s):

Shigeki Owada ◽

Kyo Nakajima ◽

Tadashi Togashi ◽

Tetsuo Kayatama ◽

Makina Yabashi

Keyword(s):

Free Electron ◽

Free Electron Laser ◽

Imaging System ◽

Laser Pulses ◽

Single Shot ◽

Simultaneous Operation ◽

One Dimensional ◽

X Ray ◽

Arrival Timing ◽

Optical Laser

Arrival timing diagnostics performed at a soft X-ray free-electron laser (FEL) beamline of SACLA are described. Intense soft X-ray FEL pulses with one-dimensional focusing efficiently induce transient changes of optical reflectivity on the surface of GaAs. The arrival timing between soft X-ray FEL and optical laser pulses was successfully measured as a spatial position of the reflectivity change. The temporal resolution evaluated from the imaging system reaches ∼10 fs. This method requires only a small portion of the incident pulse energy, which enables the simultaneous operation of the arrival timing diagnostics and experiments by introducing a wavefront-splitting scheme.

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Software for the data analysis of the arrival-timing monitor at SACLA

Journal of Synchrotron Radiation ◽

10.1107/s1600577517016654 ◽

2018 ◽

Vol 25 (2) ◽

pp. 592-603 ◽

Cited By ~ 5

Author(s):

Kyo Nakajima ◽

Yasumasa Joti ◽

Tetsuo Katayama ◽

Shigeki Owada ◽

Tadashi Togashi ◽

...

Keyword(s):

Free Electron ◽

Free Electron Laser ◽

Laser Pulses ◽

Pump Probe ◽

Network Connection ◽

Online Tools ◽

Timing Data ◽

Arrival Timing ◽

Optical Laser ◽

Analysis Environment

X-ray free-electron laser (XFEL) pulses from SPring-8 Ångstrom Compact free-electron LAser (SACLA) with a temporal duration of <10 fs have provided a variety of benefits in scientific research. In a previous study, an arrival-timing monitor was developed to improve the temporal resolution in pump–probe experiments at beamline 3 by rearranging data in the order of the arrival-timing jitter between the XFEL and the synchronized optical laser pulses. This paper presentsTiming Monitor Analyzer (TMA), a software package by which users can conveniently obtain arrival-timing data in the analysis environment at SACLA. The package is composed of offline tools that pull stored data from cache storage, and online tools that pull data from a data-handling server in semi-real time during beam time. Users can select the most suitable tool for their purpose, and share the results through a network connection between the offline and online analysis environments.

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