scholarly journals Compact coherence enhancement by subharmonic self-seeding in X-ray free-electron laser facilities

2018 ◽  
Vol 25 (2) ◽  
pp. 329-335 ◽  
Author(s):  
Eduard Prat ◽  
Sven Reiche
Keyword(s):  
Free Electron ◽  
Short Pulse ◽  
Spectral Brightness ◽  
X Rays ◽  
X Ray ◽  
X Ray Scattering ◽  
Order Of Magnitude ◽  
Longitudinal Coherence ◽  
Ultra Short Pulse ◽  
Photon Science

X-ray free-electron lasers (FELs) are cutting-edge scientific tools able to generate transversely coherent radiation with very high power and ultra-short pulse durations. The self-seeding mechanism has been proven to increase the longitudinal coherence of the FEL radiation but its efficiency could be significantly improved, especially for soft X-rays. This paper proposes the enhancement of the performance of self-seeding by combining it with the harmonic generation mechanism. In particular, by starting the process with a subharmonic of the wavelength of interest, the coherence of the produced radiation is improved, the undulator beamline becomes more compact, and the monochromator realization is simplified. Numerical simulations for SwissFEL are presented showing that the method can be employed, within a given space, to increase the spectral brightness by one order of magnitude or more with respect to standard self-seeding. This coherence enhancement will be fundamental for many photon science applications and techniques such as resonant inelastic X-ray scattering.

Thorough small-angle X-ray scattering analysis of the instability of liquid micro-jets in air

2013 ◽  
Vol 21 (1) ◽  
pp. 193-202 ◽  
Author(s):  
Benedetta Marmiroli ◽  
Fernando Cacho-Nerin ◽  
Barbara Sartori ◽  
Javier Pérez ◽  
Heinz Amenitsch
Keyword(s):  
Small Angle ◽  
Free Electron ◽  
Liquid Jets ◽  
Liquid Jet ◽  
X Rays ◽  
Free Electron Lasers ◽  
X Ray ◽  
X Ray Scattering ◽  
Break Up ◽  
Ray Scattering

Liquid jets are of interest, both for their industrial relevance and for scientific applications (more important, in particular for X-rays, after the advent of free-electron lasers that require liquid jets as sample carrier). Instability mechanisms have been described theoretically and by numerical simulation, but confirmed by few experimental techniques. In fact, these are mainly based on cameras, which is limited by the imaging resolution, and on light scattering, which is hindered by absorption, reflection, Mie scattering and multiple scattering due to complex air/liquid interfaces during jet break-up. In this communication it is demonstrated that synchrotron small-angle X-ray scattering (SAXS) can give quantitative information on liquid jet dynamics at the nanoscale, by detecting time-dependent morphology and break-up length. Jets ejected from circular tubes of different diameters (100–450 µm) and speeds (0.7–21 m s−1) have been explored to cover the Rayleigh and first wind-induced regimes. Various solvents (water, ethanol, 2-propanol) and their mixtures have been examined. The determination of the liquid jet behaviour becomes essential, as it provides background data in subsequent studies of chemical and biological reactions using SAXS or X-ray diffraction based on synchrotron radiation and free-electron lasers.

The advent of X-ray free electron lasers

Photoniques ◽  
2021 ◽  
pp. 22-26
Author(s):  
Marie-Emmanuelle Couprie
Keyword(s):  
Free Electron ◽  
Peak Power ◽  
Short Pulse ◽  
Far Infrared ◽  
Gain Medium ◽  
High Peak Power ◽  
X Rays ◽  
Free Electron Lasers ◽  
Free Electrons ◽  
X Ray

Free Electron Lasers (FEL) use free electrons in the periodic permanent magnetic field of an undulator as a gain medium. They extend from far infrared to X-rays, they are easily tunable and provide a high peak power. The advent of tunable intense (few mJ) short pulse (down to the attosecond regime) FELs with record multi GW peak power in the X-ray domain enables to explore new scientific areas. These unprecedent X-ray sources come along with versatile performance.

Photon Science at Accelerator-Based Light Sources

2010 ◽  
Vol 03 (01) ◽  
pp. 13-37 ◽  
Author(s):  
Jochen R. Schneider
Keyword(s):  
Storage Ring ◽  
Free Electron ◽  
Light Sources ◽  
Spectral Brightness ◽  
Third Generation ◽  
Free Electron Lasers ◽  
X Ray ◽  
Single Pass ◽  
The 1960S ◽  
Photon Science

Accelerator-based light sources stimulated progress in photon science in a truly extraordinary manner. The spectral brightness of storage-ring-based facilities increased by three orders of magnitude every 10 years since the 1960s. The extreme peak brightness at single-pass free electron X-ray lasers with pulse durations variable between about 1 and 300 femtoseconds will allow transformative experiments in many areas of science. This article is an attempt to show how progress in accelerator science and technology stimulated advancement in photon science, by discussing a limited number of examples of work at third generation storage ring facilities and free electron lasers. Hopes for further improvements in specific beam properties are expressed.

scholarly journals Ultra-short and ultra-intense X-ray free-electron laser single pulse in one-dimensional photonic crystals

2017 ◽  
Vol 24 (2) ◽  
pp. 376-385 ◽  
Author(s):  
Jean-Michel André ◽  
Philippe Jonnard
Keyword(s):  
Free Electron ◽  
Free Electron Laser ◽  
Short Pulse ◽  
Single Pulse ◽  
Wave Theory ◽  
One Dimensional ◽  
X Ray ◽  
Non Linear ◽  
Ultra Short Pulse ◽  
Induced Transparency

The propagation within a one-dimensional photonic crystal of a single ultra-short and ultra-intense pulse delivered by an X-ray free-electron laser is analysed with the framework of the time-dependent coupled-wave theory in non-linear media. It is shown that the reflection and the transmission of an ultra-short pulse present a transient period conditioned by the extinction length and also the thickness of the structure for transmission. For ultra-intense pulses, non-linear effects are expected: they could give rise to numerous phenomena, bi-stability, self-induced transparency, gap solitons, switching, etc., which have been previously shown in the optical domain.

scholarly journals Chemical interactions and dynamics with femtosecond X-ray spectroscopy and the role of X-ray free-electron lasers

2019 ◽  
Vol 377 (2145) ◽  
pp. 20170464 ◽  
Author(s):  
Philippe Wernet
Keyword(s):  
Structural Dynamics ◽  
Free Electron ◽  
Short Pulse ◽  
Exchange Interactions ◽  
X Rays ◽  
Free Electron Lasers ◽  
Substitution Reactions ◽  
X Ray ◽  
Orbital Interactions

X-ray free-electron lasers with intense, tuneable and short-pulse X-ray radiation are transformative tools for the investigation of transition-metal complexes and metalloproteins. This becomes apparent in particular when combining the experimental observables from X-ray spectroscopy with modern theoretical tools for calculations of electronic structures and X-ray spectra from first principles. The combination gives new insights into how charge and spin densities change in chemical reactions and how they determine reactivity. This is demonstrated for the investigations of structural dynamics with metal K-edge absorption spectroscopy, spin states in excited-state dynamics with metal 3p-3d exchange interactions, the frontier-orbital interactions in dissociation and substitution reactions with metal-specific X-ray spectroscopy, and studies of metal oxidation states with femtosecond pulses for ‘probe-before-destroy’ spectroscopy. The role of X-ray free-electron lasers is addressed with thoughts about how they enable ‘bringing back together’ different aspects of the same problem and this is thought to go beyond a conventional review paper where these aspects are formulated in italic font type in a prequel, an interlude and in a sequel. This article is part of the theme issue ‘Measurement of ultrafast electronic and structural dynamics with X-rays'.

Study of free electron laser and ultra-short pulse x-ray generation on NewSUBARU

2004 ◽  
pp. II-85-II-86
Author(s):  
S. Amano ◽  
S. Miyamoto ◽  
T. Inoue ◽  
Y. Shoji ◽  
T. Mochizuki
Keyword(s):  
Free Electron ◽  
Free Electron Laser ◽  
Short Pulse ◽  
X Ray ◽  
Ultra Short Pulse

The study of time dependent, broadband X-ray emission from ultra-short pulse laser produced plasmas

1994 ◽  
Author(s):  
Ronnie Shepherd ◽  
Rex Booth ◽  
Dwight Price ◽  
Rosemary Walling ◽  
Richard More ◽  
...  
Keyword(s):  
Pulse Laser ◽  
Short Pulse ◽  
Time Dependent ◽  
X Ray ◽  
Short Pulse Laser ◽  
Ultra Short Pulse ◽  
Ultra Short Pulse Laser

Mesoscopic structure of SiC fibers by neutron and x-ray scattering

1996 ◽  
Vol 11 (5) ◽  
pp. 1169-1178 ◽  
Author(s):  
Kentaro Suzuya ◽  
Michihiro Furusaka ◽  
Noboru Watanabe ◽  
Makoto Osawa ◽  
Kiyohito Okamura ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Volume Fraction ◽  
X Rays ◽  
X Ray ◽  
Sic Fibers ◽  
X Ray Scattering ◽  
Mesoscopic Structure ◽  
Angle Scattering ◽  
Momentum Transfer Range ◽  
First Time

Mesoscopic structures of SiC fibers produced from polycarbosilane by different methods were studied by diffraction and small-angle scattering of neutrons and x-rays. Microvoids of a size of 4–10 Å in diameter have been observed for the first time by neutron scattering in a medium momentum transfer range (Q = 0.1–1.0 Å−1). The size and the volume fraction of β–SiC particles were determined for fibers prepared at different heat-treatment temperatures. The results show that wide-angle neutron scattering measurements are especially useful for the study of the mesoscopic structure of multicomponent materials.

Resonant Inelastic X-ray Scattering at the ESRF: Hard and Soft X-rays

2012 ◽  
Vol 25 (4) ◽  
pp. 9-15 ◽  
Author(s):  
L. Braicovich ◽  
N. B. Brookes ◽  
G. Ghiringhelli ◽  
M. Minola ◽  
G. Monaco ◽  
...  
Keyword(s):  
X Rays ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering
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