A5038975156- Advanced X-ray Imaging Techniques
- Advancements in Photolithography Techniques
- X-ray Spectroscopy and Fluorescence Analysis
- Electron and X-Ray Spectroscopy Techniques
- Advanced Surface Polishing Techniques
- Optical Coatings and Gratings
- Surface Roughness and Optical Measurements
- Calibration and Measurement Techniques
- Adaptive optics and wavefront sensing
- Laser Material Processing Techniques
- Particle Accelerators and Free-Electron Lasers
- Optical Systems and Laser Technology
- Nuclear Physics and Applications
- Ion-surface interactions and analysis
- Laser-Plasma Interactions and Diagnostics
- Silicon and Solar Cell Technologies
- Crystallography and Radiation Phenomena
- High-pressure geophysics and materials
- Advanced Electron Microscopy Techniques and Applications
- Integrated Circuits and Semiconductor Failure Analysis
- Thin-Film Transistor Technologies
- Astrophysical Phenomena and Observations
- Infrared Target Detection Methodologies
- Diamond and Carbon-based Materials Research
- CCD and CMOS Imaging Sensors
Lawrence Livermore National Laboratory
2014-2024
Centre National de la Recherche Scientifique
2016-2019
Lawrence Berkeley National Laboratory
1994-2019
Université Paris-Saclay
2016-2019
Laboratoire Charles Fabry
2016-2019
Technical University of Denmark
2019
Institut d’Optique Graduate School
2016-2019
SLAC National Accelerator Laboratory
2009-2010
Czech Academy of Sciences, Institute of Physics
2009
Deutsches Elektronen-Synchrotron DESY
2009
The Atmospheric Imaging Assembly (AIA) instrument onboard the Solar Dynamics Observatory (SDO) is an array of four normal-incidence reflecting telescopes that image Sun in ten EUV and UV wavelength channels. We present initial photometric calibration AIA, based on preflight measurements response telescope components. estimated accuracy order 25%, which consistent with results comparisons full-disk irradiance spectral models. also describe characterization performance, including resolution,...
We have searched for solar axions or other pseudoscalar particles that couple to two photons by using the CERN Axion Solar Telescope (CAST) setup. Whereas we previously reported results from CAST with evacuated magnet bores (Phase I), setting limits on lower mass axions, here report where were filled 4He gas II) of variable pressure. The introduction generates a refractive photon mγ, thereby achieving maximum possible conversion rate those axion masses ma match mγ. With 160 different...
Measurements of the spatial and temporal coherence single, femtosecond x-ray pulses generated by first hard free-electron laser, Linac Coherent Light Source, are presented. Single-shot measurements were performed at 780 eV photon energy using apertures containing double pinholes in "diffract-and-destroy" mode. We determined a length 17 μm vertical direction, which is approximately size focused Source beam same direction. The analysis diffraction patterns produced with largest separation...
The soft x-ray materials science instrument is the second operational beamline at linac coherent light source free electron laser. operates with a photon energy range of 480-2000 eV and features grating monochromator as well bendable refocusing mirrors. A broad experimental stations may be installed to study diverse scientific topics such as: ultrafast chemistry, surface science, highly correlated systems, matter under extreme conditions, laboratory astrophysics. Preliminary commissioning...
A 5 ps gated framing camera was demonstrated using the pulse-dilation of a drifting electron signal. The is achieved by accelerating photoelectron derived information pulse with time varying potential [R. D. Prosser, J. Phys. E 9, 57 (1976)]. temporal dependence causes birth dependent axial velocity dispersion that spreads as it transits drift region. expanded then imaged conventional microchannel plate based and effective gating combined instrument reduced over alone. In region, image...
We present the x-ray optical design of soft materials science instrument at Linac Coherent Light Source, consisting a varied line-spaced grating monochromator and Kirkpatrick-Baez refocusing optics. Results from commissioning are shown. A resolving power 3000 was achieved, which is within factor two goal.
This paper reports novel measurements of x-ray optical radiation on an absolute scale from the intense and ultra-short generated in soft regime a free electron laser.We give brief description detection principle for which was specifically adapted this photon energy range.We present data characterizing instrument at Linac Coherent Light Source (LCLS) with respect to radiant power output transmission by using detector temporarily placed downstream end instrument.This provides estimation...
The recent development of x-ray free electron lasers providing coherent, femtosecond-long pulses high brilliance and variable energy opens new areas scientific research in a variety disciplines such as physics, chemistry, biology. Pump-probe experimental techniques which observe the temporal evolution systems after optical or pulse excitation are one main schemes currently use for ultrafast studies. key challenge these experiments is to reliably achieve spatial overlap pulses. Here we...
Abstract Key insights in materials at extreme temperatures and pressures can be gained by accurate measurements that determine the electrical conductivity. Free-electron laser pulses ionize excite matter out of equilibrium on femtosecond time scales, modifying electronic ionic structures enhancing scattering properties. The transient evolution conductivity manifests energy coupling from high temperature electrons to low ions. Here we combine accelerator-based, high-brightness multi-cycle...
The refractive index n = 1 - δ + iβ of Si in the energy range 50–180 eV is investigated with angle-dependent reflectance measurements. optical constants and β are both determined by fitting to Fresnel equations. results this method compared values atomic tables derived from experimental data for implementation Kramers–Kronig relations δ. samples were prepared UV irradiation HF:ethanol dipping H passivate surface. It found that 8–15% too high region 50–90 eV. This attributed missing...
We report on a series of normal-incidence reflectance measurements at wavelengths just longer than the beryllium K-edge (11.1 nm) from molybdenum/beryllium multilayer mirrors. The highest peak was 68.7 ± 0.2% λ = 11.3 nm obtained mirror with 70 bilayers ending in beryllium. To our knowledge, this is that has been demonstrated 1–80-nm spectral range.
This work discusses the experimental determination of optical constants (refractive index) DC-magnetron-sputtered boron carbide films in 30-770 eV photon energy range. Transmittance measurements three with thicknesses 54.2, 79.0, and 112.5 nm were performed for this purpose. These are believed to be first published data refractive index range above 160 near-edge x-ray absorption fine structure regions around K (188 eV), carbon (284.2 oxygen (543.1 eV) edges. The density, composition, surface...
The first X-ray free electron laser (XFEL) at keV energies will be the Linac Coherent Light Source (LCLS), located SLAC National Accelerator Laboratory. Scheduled to begin operation in 2009, this first-of-a-kind source produce ultra-short pulses of unprecedented brightness 0.8 8 harmonic photon energy regime. Much effort has been invested predicting and modeling XFEL properties undulator exit; however, as most LCLS experiments are ultimately dependent on beam focal spot it is equally...
The Solar Ultraviolet Imager (SUVI) is one of the several instruments that will fly on board next generation Geostationary Operational Environmental Satellites R-U platforms, as part National Oceanic and Atmospheric Administration's space weather monitoring fleet. SUVI a generalized Cassegrain telescope employs multilayer-coated optics operate in six extreme ultraviolet (EUV) narrow bandpasses centered at 93.9, 131.2, 171.1, 195.1, 284.2 303.8 Å. innovation design first EUV solar has...
Traditional multilayer reflective optics that have been used in the past for imaging at x-ray photon energies as high 200 keV are governed by classical wave phenomena. However, their behavior higher is unknown, because of increasing effect incoherent scattering and disagreement between experimental theoretical optical properties materials hard gamma-ray regimes. Here, we demonstrate can operate efficiently according to physics up least 384 keV. We also use particle transport simulations...
Substrate defect planarization has been shown to increase the laser resistance of 1053 nm mirror coatings greater than 100 J/cm2, an 20-fold, when tested with 10 ns pulses. surface particles that are overcoated optical interference become nodular defects, which behave as microlenses intensifying light into structure. By a discrete process angle-dependent ion etching and unidirectional ion-beam deposition, substrate defects can be reduced in cross-sectional area by over 90%.
We exposed bulk SiC and films of B4C to single 25 fs long free-electron-laser pulses with wavelengths between 13.5 32 nm. The materials are candidates for x-ray free-electron laser optics. found that the threshold surface-damage samples exceeds fluence required thermal melting at all wavelengths. damage film sample shows a strong wavelength dependence. For 21.7 nm, is equal or threshold, whereas nm falls below threshold.
Materials used for hard x-ray-free-electron laser (XFEL) optics must withstand high-intensity x-ray pulses. The advent of the Linac Coherent Light Source has enabled us to expose candidate optical materials, such as bulk B4C and SiC films, 0.83 keV XFEL pulses with pulse energies between 1 μJ 2 mJ determine short-pulse damage thresholds. fluence required onset single is around melt slightly lower multiple We observed strong mechanical cracking in which may be due larger penetration depths x-rays.
We have developed new, Mg/SiC multilayer coatings with corrosion barriers which can be used to efficiently and simultaneously reflect extreme ultraviolet (EUV) radiation in single or multiple narrow bands centered at wavelengths the spectral region from 25 80 nm. Corrosion mitigation was attempted through use of Al-Mg Al thin layers. Three different design concepts were deposited by magnetron sputtering reflectance measured near-normal incidence a broad range. Standard multilayers also for...
Transmission measurements for the optical constants delta, beta of thecomplex refractive index n = 1 - delta + ibeta molybdenum are performed in energy range 60-930eV. Free-standing C/Mo/C foils five different thicknesses used, and results normalized presence carbon layers samples. These absorption combined with previous experimental data lower values fromthe atomic tables to obtain imaginary (absorptive) part 1-30,000 eV. The real(dispersive) was calculated from Kramers-Kronig analysis...
The development and properties of reflective coatings for the x-ray offset mirror systems Linac Coherent Light Source (LCLS) free-electron laser (FEL) are discussed in this manuscript. uniquely high instantaneous dose LCLS FEL beam translates to strict limits terms materials choice, thus leading an design consisting a coating deposited on silicon substrate. wavefront preservation requirements these mirrors result stringent surface figure finish specifications. DC-magnetron sputtered B4C SiC...
We present experimental results on the development and testing of extreme ultraviolet (EUV) reflective multilayer coatings that will be used in Atmospheric Imaging Assembly (AIA) instrument. The AIA, comprising four normal incidence telescopes, is one three instruments aboard Solar Dynamics Observatory mission, part NASA's Living with a Star program, currently scheduled for launch 2008. Seven different used, covering wavelength region from 93.9 to 335.4 Å.
Multilayer coating results are discussed for the primary and secondary mirrors of micro-exposure tool (MET): a 0.30 NA lithographic imaging system with 200 microm x 600 field view at wafer plane, operating in extreme ultraviolet (EUV) region an illumination wavelength around 13.4 nm. Mo/Si multilayers were deposited by DC-magnetron sputtering on large-area, curved MET camera substrates. A velocity modulation technique was implemented to consistently achieve multilayer thickness profiles...