Two-dimensional tilt control of electron bunch for X-ray free electron laser

AbstractFor a real, meaningful pump-probe experiment with attosecond temporal resolution, an intense isolated attosecond pulse is in demand. For that purpose we report the generation of an intense isolated attosecond pulse, especially in X-ray region using a current-enhanced self-amplified spontaneous emission in a free electron laser (FEL). We use a few cycle laser pulse to manipulate the electron-bunch inside a two-period planar wiggler. In our study, we employ the electron beam parameters of Pohang Accelerator Laboratory (PAL)-XFEL. The RF phase effect of accelerator columns on the longitudinal energy distribution profile and current profile of electron-bunch is also studied, aiming that these results can be experimentally realized in PAL-XFEL. We show indeed that the manipulation of electron-energy bunch profile may lead to the generation of an isolated attosecond hard X-ray pulse: 150 attosecond radiation pulse at 0.1 nm wavelength can be generated.

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Slice collective dynamics, projected emittance deterioration and free electron laser performances detrimental effects

Journal of Plasma Physics ◽

10.1017/s0022377820001324 ◽

2020 ◽

Vol 86 (6) ◽

Author(s):

G. Dattoli ◽

S. Di Mitri ◽

F. Nguyen ◽

A. Petralia

Keyword(s):

Phase Space ◽

Output Power ◽

Free Electron ◽

Free Electron Laser ◽

Coherence Length ◽

Electron Bunch ◽

Laser Intensity ◽

Beam Transport ◽

X Ray ◽

Laser Dynamics

Self-amplified spontaneous emission (SASE) free electron laser (FEL) devices have disclosed an unexpected interplay between the laser intensity growth and regions of the electron bunch of the order of the coherence length. They are usually identified with the bunch slice and contribute to the laser dynamics with their own characteristics. The dynamical effects inducing geometrical and phase space misalignment of bunch slice in X-ray operating FELs can be traced back to a plethora of phenomena, both in the Linac accelerating section or inside the beam transport optic magnet. They are responsible for spoiling of the beam projected qualities and, if not corrected properly, induce an increase of the saturation length and a decreasing of the output power. We discuss the inclusion of these effects in models employing scaling formulae.

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Development of Focusing System for X-Ray Free Electron Laser

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.516.251 ◽

2012 ◽

Vol 516 ◽

pp. 251-256 ◽

Cited By ~ 1

Author(s):

Hidekazu Mimura ◽

Hitoshi Ohmori ◽

Kazuto Yamauchi

Keyword(s):

Radiation Damage ◽

Free Electron ◽

Free Electron Laser ◽

Two Dimensional ◽

Coherent Light ◽

X Ray ◽

Synchrotron Facility ◽

New Type

The X-ray free electron laser (XFEL) is a new type of synchrotron facility, which can produce full coherent light at X-ray wavelength ranges. Its focusing system makes it possible to create an extremely intensive XFEL beam. Long-size focusing mirrors are necessary for this system from the viewpoint of X-ray radiation damage. We established the figuring system with an accuracy at the nanometre level. The focusing mirror has an elliptical curved shape with a length of 400 mm. Figure accuracy with a peak-to-valley height of 2 nm is achieved. The Kirkpatrick Baez focusing system was also designed and developed for two-dimensional focusing at Japanese XFEL.

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A micro channel-cut crystal X-ray monochromator for a self-seeded hard X-ray free-electron laser

Journal of Synchrotron Radiation ◽

10.1107/s1600577519008841 ◽

2019 ◽

Vol 26 (5) ◽

pp. 1496-1502 ◽

Cited By ~ 5

Author(s):

Taito Osaka ◽

Ichiro Inoue ◽

Ryota Kinjo ◽

Takashi Hirano ◽

Yuki Morioka ◽

...

Keyword(s):

Free Electron ◽

Free Electron Laser ◽

Electron Bunch ◽

Optical Pulse ◽

Seed Pulse ◽

Micro Channel ◽

Free Electron Lasers ◽

X Ray ◽

Optical Delay ◽

Temporal Overlap

A channel-cut Si(111) crystal with a channel width of 90 µm was developed for achieving reflection self-seeding in hard X-ray free-electron lasers (XFELs). With the crystal a monochromatic seed pulse is produced from a broadband XFEL pulse generated in the first undulator section with an optical delay of 119 fs at 10 keV. The small optical delay allows a temporal overlap between the seed optical pulse and the electron bunch by using a small magnetic chicane for the electron beam placed between two undulator sections. Peak reflectivity reached 67%, which is reasonable compared with the theoretical value of 81%. By using this monochromator, a monochromatic seed pulse without broadband background in the spectrum was obtained at SACLA with a conversion efficiency from a broadband XFEL pulse of 2 × 10−2, which is ∼10 times higher than the theoretical efficiency of transmission self-seeding using a thin diamond (400) monochromator.

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