scholarly journals Demonstration of Transmission Mode Soft X-ray NEXAFS Using Third- and Fifth-Order Harmonics of FEL Radiation at SACLA BL1

2020 ◽  
Vol 10 (21) ◽  
pp. 7852
Author(s):  
Hiroshi Iwayama ◽  
Masanari Nagasaka ◽  
Ichiro Inoue ◽  
Shigeki Owada ◽  
Makina Yabashi ◽  
...  
Keyword(s):  
Fine Structure ◽  
Free Electron ◽  
Free Electron Laser ◽  
Transmission Mode ◽  
Pump Probe ◽  
X Ray ◽  
The Third ◽  
Nexafs Spectroscopy ◽  
Fifth Order ◽  
X Ray Absorption

We demonstrate the applicability of third- and fifth-order harmonics of free-electron laser (FEL) radiation for soft X-ray absorption spectroscopy in the transmission mode at SACLA BL1, which covers a photon energy range of 20 to 150 eV in the fundamental FEL radiation. By using the third- and fifth-order harmonics of the FEL radiation, we successfully recorded near-edge X-ray absorption fine structure (NEXAFS) spectra for Ar 2p core ionization and CO2 C 1s and O 1s core ionizations. Our results show that the utilization of third- and fifth-order harmonics can significantly extend the available photon energies for NEXAFS spectroscopy using an FEL and opens the door to femtosecond pump-probe NEXAFS using a soft X-ray FEL.

scholarly journals Double chirp-taper x-ray free-electron laser for attosecond pump-probe experiments

2019 ◽  
Vol 22 (5) ◽  
Author(s):  
Zhen Zhang ◽  
Joseph Duris ◽  
James P. MacArthur ◽  
Zhirong Huang ◽  
Agostino Marinelli
Keyword(s):  
Free Electron ◽  
Free Electron Laser ◽  
Pump Probe ◽  
X Ray

scholarly journals Imaging at an x-ray absorption edge using free electron laser pulses for interface dynamics in high energy density systems

2017 ◽  
Vol 88 (5) ◽  
pp. 053501 ◽  
Author(s):  
M. A. Beckwith ◽  
S. Jiang ◽  
A. Schropp ◽  
A. Fernandez-Pañella ◽  
H. G. Rinderknecht ◽  
...  
Keyword(s):  
Energy Density ◽  
Absorption Edge ◽  
Free Electron ◽  
Free Electron Laser ◽  
Laser Pulses ◽  
High Energy ◽  
High Energy Density ◽  
Interface Dynamics ◽  
X Ray ◽  
X Ray Absorption

scholarly journals Switching of the harmonic order in free-electron lasers by controlling the density modulation of an electron bunch

2018 ◽  
Vol 25 (5) ◽  
pp. 1317-1322 ◽  
Author(s):  
Norihiro Sei ◽  
Hiroshi Ogawa ◽  
QiKa Jia
Keyword(s):  
Free Electron ◽  
Free Electron Laser ◽  
Extreme Ultraviolet ◽  
Free Electron Lasers ◽  
Harmonic Order ◽  
Third Harmonic ◽  
X Ray ◽  
The Third ◽  
Density Modulation ◽  
Higher Harmonic

It was demonstrated that harmonic order in free-electron laser (FEL) oscillations could be switched by adjusting the dispersive gap of the optical klystron ETLOK-III in the storage ring NIJI-IV. The effective gains for the fundamental and third-harmonic FEL oscillations were evaluated and it was confirmed that the FEL oscillated at the order of the harmonic with the higher effective gain. The ratio between the effective gain for the fundamental and that for the third harmonic was controlled by the dispersive gap. It was also demonstrated that a spectral measurement of the FEL-based Compton scattering X-ray beam was effective for directly observing the switching of the harmonic order. These results contribute to the development of higher-harmonic FEL oscillations suppressing the fundamental FEL oscillation in the extreme ultraviolet and X-ray regions.

Near Edge X-Ray Absorption Fine Structure (NEXAFS) Microscopy: Chemical Analysis at Sub Visible Spatial Resolution

1997 ◽  
Vol 3 (S2) ◽  
pp. 851-852
Author(s):  
H. Ade
Keyword(s):  
Fine Structure ◽  
Compositional Analysis ◽  
High Sensitivity ◽  
Linear Dichroism ◽  
X Rays ◽  
X Ray ◽  
Absorption Fine ◽  
Nexafs Spectroscopy ◽  
Wide Range ◽  
X Ray Absorption

Infrared, Raman, and fluorescence/luminescence microspectroscopy/microscopy in many instances seek to provide high sensitivity compositional and functional information that goes beyond mere elemental composition. This goal is shared by NEXAFS microscopy, in which Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy is employed to provide chemical sensitivity and can be relatively easily adopted in a scanning transmission x-ray microscope (STXM). In addition to compositional information, NEXAFS microscopy can exploit the dependence of x-ray absorption resonances on the bond orientation relative to the linearly polarized x rays (linear dichroism microscopy). For compositional analysis, NEXAFS microscopy is analogous to Electron Energy Loss Spectroscopy (EELS) in an electron microscope. However, when utilizing near edge spectral features, NEXAFS microscopy requires a considerable lower dose than EELS microscopy which makes it very suitable to studying radiation sensitive materials such as polymers. NEXAFS has shown to have excellent sensitivity to a wide range of moieties in polymers, including sensitivity to substitution isomerism.

scholarly journals Near edge x-ray absorption fine structure spectroscopy with x-ray free-electron lasers

2009 ◽  
Vol 95 (13) ◽  
pp. 134102 ◽  
Author(s):  
D. P. Bernstein ◽  
Y. Acremann ◽  
A. Scherz ◽  
M. Burkhardt ◽  
J. Stöhr ◽  
...  
Keyword(s):  
Fine Structure ◽  
Free Electron ◽  
Free Electron Lasers ◽  
X Ray ◽  
Absorption Fine ◽  
X Ray Absorption

Investigating the structure of boron nitride nanotubes by near-edge X-ray absorption fine structure (NEXAFS) spectroscopy

2005 ◽  
Vol 7 (6) ◽  
pp. 1103 ◽  
Author(s):  
Tirandai Hemraj-Benny ◽  
Sarbajit BanerjeeCurrent address: Department ◽  
Sharadha Sambasivan ◽  
Daniel A. Fischer ◽  
Weiqiang Han ◽  
...  
Keyword(s):  
Fine Structure ◽  
Boron Nitride ◽  
Boron Nitride Nanotubes ◽  
X Ray ◽  
Absorption Fine ◽  
Nexafs Spectroscopy ◽  
X Ray Absorption

Hybrid modelling of a high-power X-ray attenuator plasma

2018 ◽  
Vol 25 (3) ◽  
pp. 671-685
Author(s):  
Álvaro Martín Ortega ◽  
Ana Lacoste ◽  
Tiberiu Minea
Keyword(s):  
Free Electron ◽  
Free Electron Laser ◽  
Radial Profile ◽  
Analytical Description ◽  
Gas Temperature ◽  
Beam Path ◽  
Power Absorption ◽  
X Ray ◽  
Absorbed Power ◽  
X Ray Absorption

X-ray gas attenuators act as stress-free high-pass filters for synchrotron and free-electron laser beamlines to reduce the heat load in downstream optical elements without affecting other properties of the X-ray beam. The absorption of the X-ray beam triggers a cascade of processes that ionize and heat up the gas locally, changing its density and therefore the X-ray absorption. Aiming to understand and predict the behaviour of the gas attenuator in terms of efficiencyversusgas pressure, a hybrid model has been developed, combining three approaches: an analytical description of the X-ray absorption; Monte Carlo for the electron thermalization; and a fluid treatment for the electron diffusion, recombination and excited-states relaxation. The model was applied to an argon-filled attenuator prototype built and tested at the European Synchrotron Radiation Facility, at a pressure of 200 mbar and assuming stationary conditions. The results of the model showed that the electron population thermalizes within a few nanoseconds after the X-ray pulse arrival and it occurs just around the X-ray beam path, recombining in the bulk of the gas rather than diffusing to the attenuator walls. The gas temperature along the beam path reached 850 K for 770 W of incident power and 182 W m−1of absorbed power. Around 70% of the absorbed power is released as visible and UV radiation rather than as heat to the gas. Comparison of the power absorption with the experiment showed an overall agreement both with the plasma radial profile and power absorption trend, the latter within an error smaller than 20%. This model can be used for the design and operation of synchrotron gas attenuators and as a base for a time-dependent model for free-electron laser attenuators.

Femtosecond x-ray absorption spectroscopy with hard x-ray free electron laser

2013 ◽  
Vol 103 (13) ◽  
pp. 131105 ◽  
Author(s):  
Tetsuo Katayama ◽  
Yuichi Inubushi ◽  
Yuki Obara ◽  
Takahiro Sato ◽  
Tadashi Togashi ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Free Electron ◽  
Free Electron Laser ◽  
X Ray ◽  
X Ray Absorption
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