scholarly journals XUV double-pulses with femtosecond to 650 ps separation from a multilayer-mirror-based split-and-delay unit at FLASH

2018 ◽  
Vol 25 (5) ◽  
pp. 1517-1528 ◽  
Author(s):  
Mario Sauppe ◽  
Dimitrios Rompotis ◽  
Benjamin Erk ◽  
Sadia Bari ◽  
Tobias Bischoff ◽  
...  
Keyword(s):  
Free Electron ◽  
Extreme Ultraviolet ◽  
Normal Incidence ◽  
Laser Flash ◽  
Time Range ◽  
Time Resolved ◽  
Spatial Overlap ◽  
Multilayer Mirror ◽  
Delay Unit ◽  
Long Time

Extreme ultraviolet (XUV) and X-ray free-electron lasers enable new scientific opportunities. Their ultra-intense coherent femtosecond pulses give unprecedented access to the structure of undepositable nanoscale objects and to transient states of highly excited matter. In order to probe the ultrafast complex light-induced dynamics on the relevant time scales, the multi-purpose end-station CAMP at the free-electron laser FLASH has been complemented by the novel multilayer-mirror-based split-and-delay unit DESC (DElay Stage for CAMP) for time-resolved experiments. XUV double-pulses with delays adjustable from zero femtoseconds up to 650 picoseconds are generated by reflecting under near-normal incidence, exceeding the time range accessible with existing XUV split-and-delay units. Procedures to establish temporal and spatial overlap of the two pulses in CAMP are presented, with emphasis on the optimization of the spatial overlap at long time-delays via time-dependent features, for example in ion spectra of atomic clusters.

scholarly journals The free-electron laser FLASH

2015 ◽  
Vol 3 ◽  
Author(s):  
Siegfried Schreiber ◽  
Bart Faatz
Keyword(s):  
Free Electron ◽  
Free Electron Laser ◽  
Extreme Ultraviolet ◽  
Laser Flash ◽  
Single Shot ◽  
Short Pulses ◽  
X Ray ◽  
Pump And Probe ◽  
User Facility ◽  
Diffraction Imaging

FLASH at DESY, Hamburg, Germany is the first free-electron laser (FEL) operating in the extreme ultraviolet (EUV) and soft x-ray wavelength range. FLASH is a user facility providing femtosecond short pulses with an unprecedented peak and average brilliance, opening new scientific opportunities in many disciplines. The first call for user experiments has been launched in 2005. The FLASH linear accelerator is based on TESLA superconducting technology, providing several thousands of photon pulses per second to user experiments. Probing femtosecond-scale dynamics in atomic and molecular reactions using, for instance, a combination of x-ray and optical pulses in a pump and probe arrangement, as well as single-shot diffraction imaging of biological objects and molecules, are typical experiments performed at the facility. We give an overview of the FLASH facility, and describe the basic principles of the accelerator. Recently, FLASH has been extended by a second undulator beamline (FLASH2) operated in parallel to the first beamline, extending the capacity of the facility by a factor of two.

Timing methodologies and studies at the FERMI free-electron laser

2018 ◽  
Vol 25 (1) ◽  
pp. 44-51 ◽  
Author(s):  
Riccardo Mincigrucci ◽  
Filippo Bencivenga ◽  
Emiliano Principi ◽  
Flavio Capotondi ◽  
Laura Foglia ◽  
...  
Keyword(s):  
Free Electron ◽  
Free Electron Laser ◽  
Electronic Effect ◽  
Extreme Ultraviolet ◽  
Laser Pulses ◽  
Time Resolved ◽  
New Era ◽  
Condensed Materials ◽  
Optical Laser ◽  
Partial Depletion

Time-resolved investigations have begun a new era of chemistry and physics, enabling the monitoring in real time of the dynamics of chemical reactions and matter. Induced transient optical absorption is a basic ultrafast electronic effect, originated by a partial depletion of the valence band, that can be triggered by exposing insulators and semiconductors to sub-picosecond extreme-ultraviolet pulses. Besides its scientific and fundamental implications, this process is very important as it is routinely applied in free-electron laser (FEL) facilities to achieve the temporal superposition between FEL and optical laser pulses with tens of femtoseconds accuracy. Here, a set of methodologies developed at the FERMI facility based on ultrafast effects in condensed materials and employed to effectively determine the FEL/laser cross correlation are presented.

scholarly journals The TRIXS end-station for femtosecond time-resolved resonant inelastic x-ray scattering experiments at the soft x-ray free-electron laser FLASH

2020 ◽  
Vol 7 (5) ◽  
pp. 054301 ◽  
Author(s):  
S. Dziarzhytski ◽  
M. Biednov ◽  
B. Dicke ◽  
A. Wang ◽  
P. S. Miedema ◽  
...  
Keyword(s):  
Free Electron ◽  
Free Electron Laser ◽  
Laser Flash ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

scholarly journals Segmental motion and rotational diffusion of the Ca2+-translocating adenosine triphosphatase of sarcoplasmic reticulum, measured by time-resolved phosphorescence depolarization

1983 ◽  
Vol 213 (1) ◽  
pp. 67-74 ◽  
Author(s):  
A Speirs ◽  
C H Moore ◽  
D H Boxer ◽  
P B Garland
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Rotational Diffusion ◽  
Linear Dichroism ◽  
Laser Flash ◽  
Time Range ◽  
Segmental Motion ◽  
Rotational Mobility ◽  
Temperature Dependent ◽  
Time Resolved ◽  
Limited Motion

We studied the rotational mobility of the Ca2+ + Mg2+-activated ATPase in skeletal-muscle sarcoplasmic-reticulum vesicles, using time-resolved measurements of the depolarization of laser-flash-excited phosphorescence of the extrinsic triplet probe erythrosin. Our results are in general agreement with those of others [Bürkli & Cherry (1981) Biochemistry 20, 138-145] obtained by linear dichroism methods. In addition, we directly observed fast depolarization in the 1-5 microseconds time range that can be attributed to limited motion of part of the protein (segmental motion). Temperature-dependent changes in phosphorescence anisotropy indicated the onset of a conformational change in structure of the Ca2+ + Mg2+-activated ATPase at 11-13 degrees C. We also describe the synthesis of 5-iodoacetamidoerythrosin.

scholarly journals Generating circularly polarized radiation in the extreme ultraviolet spectral range at the free-electron laser FLASH

2017 ◽  
Vol 88 (5) ◽  
pp. 053903 ◽  
Author(s):  
Clemens von Korff Schmising ◽  
David Weder ◽  
Tino Noll ◽  
Bastian Pfau ◽  
Martin Hennecke ◽  
...  
Keyword(s):  
Spectral Range ◽  
Free Electron ◽  
Free Electron Laser ◽  
Extreme Ultraviolet ◽  
Laser Flash ◽  
Circularly Polarized ◽  
Circularly Polarized Radiation ◽  
Polarized Radiation

scholarly journals Free Electron Laser Measurement of Liquid Carbon Reflectivity in the Extreme Ultraviolet

Photonics ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. 35
Author(s):  
Sumana Raj ◽  
Shane Devlin ◽  
Riccardo Mincigrucci ◽  
Craig Schwartz ◽  
Emiliano Principi ◽  
...  
Keyword(s):  
Free Electron ◽  
Free Electron Laser ◽  
Lattice Dynamics ◽  
Extreme Ultraviolet ◽  
Wavelength Dependence ◽  
Optically Pumped ◽  
Liquid Carbon ◽  
Electronic Temperature ◽  
Time Resolved ◽  
Probing Depth

Ultrafast time-resolved extreme ultraviolet (EUV) reflectivity measurements of optically pumped amorphous carbon (a-C) have been performed with the FERMI free electron laser (FEL). This work extends the energy range used in previous reflectivity studies and adds polarization dependence. The EUV probe is known to be sensitive to lattice dynamics, since in this range the reflectivity is essentially unaffected by the photo-excited surface plasma. The exploitation of both s- and p-polarized EUV radiation permits variation of the penetration depth of the probe; a significant increase in the characteristic time is observed upon increasing the probing depth (1 vs. 5 ps) due to hydrodynamic expansion and consequent destruction of the excited region, implying that there is only a short window during which the probed region is in the isochoric regime. A weak wavelength dependence of the reflectivity is found, consistent with previous measurements and implying a maximum electronic temperature of 0.8 eV ± 0.4.

Microspectroscopy Using a Solid Immersion Lens

2001 ◽  
Vol 7 (S2) ◽  
pp. 148-149
Author(s):  
C.D. Poweleit ◽  
J Menéndez
Keyword(s):  
Spatial Resolution ◽  
Focal Plane ◽  
Numerical Aperture ◽  
Normal Incidence ◽  
Spot Size ◽  
Index Of Refraction ◽  
Objective Lens ◽  
Improvement Factor ◽  
Oil Immersion ◽  
Long Time

Oil immersion lenses have been used in optical microscopy for a long time. The light’s wavelength is decreased by the oil’s index of refraction n and this reduces the minimum spot size. Additionally, the oil medium allows a larger collection angle, thereby increasing the numerical aperture. The SIL is based on the same principle, but offers more flexibility because the higher index material is solid. in particular, SILs can be deployed in cryogenic environments. Using a hemispherical glass the spatial resolution is improved by a factor n with respect to the resolution obtained with the microscope’s objective lens alone. The improvement factor is equal to n2 for truncated spheres.As shown in Fig. 1, the hemisphere SIL is in contact with the sample and does not affect the position of the focal plane. The focused rays from the objective strike the lens at normal incidence, so that no refraction takes place.

Generation and measurement of intense few-femtosecond superradiant extreme-ultraviolet free-electron laser pulses

2021 ◽  
Author(s):  
Najmeh S. Mirian ◽  
Michele Di Fraia ◽  
Simone Spampinati ◽  
Filippo Sottocorona ◽  
Enrico Allaria ◽  
...  
Keyword(s):  
Free Electron ◽  
Free Electron Laser ◽  
Extreme Ultraviolet ◽  
Laser Pulses

scholarly journals Measuring the frequency chirp of extreme-ultraviolet free-electron laser pulses by transient absorption spectroscopy

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Thomas Ding ◽  
Marc Rebholz ◽  
Lennart Aufleger ◽  
Maximilian Hartmann ◽  
Veit Stooß ◽  
...  
Keyword(s):  
Free Electron ◽  
Free Electron Laser ◽  
Transient Absorption ◽  
Extreme Ultraviolet ◽  
Ultrashort Pulses ◽  
Laser Pulses ◽  
Transient Absorption Spectroscopy ◽  
Energy Structure ◽  
Frequency Chirp

AbstractHigh-intensity ultrashort pulses at extreme ultraviolet (XUV) and x-ray photon energies, delivered by state-of-the-art free-electron lasers (FELs), are revolutionizing the field of ultrafast spectroscopy. For crossing the next frontiers of research, precise, reliable and practical photonic tools for the spectro-temporal characterization of the pulses are becoming steadily more important. Here, we experimentally demonstrate a technique for the direct measurement of the frequency chirp of extreme-ultraviolet free-electron laser pulses based on fundamental nonlinear optics. It is implemented in XUV-only pump-probe transient-absorption geometry and provides in-situ information on the time-energy structure of FEL pulses. Using a rate-equation model for the time-dependent absorbance changes of an ionized neon target, we show how the frequency chirp can be directly extracted and quantified from measured data. Since the method does not rely on an additional external field, we expect a widespread implementation at FELs benefiting multiple science fields by in-situ on-target measurement and optimization of FEL-pulse properties.

Sign in / Sign up

Export Citation Format

Share Document