Scan Science and Technology
Contact Leading Edge Experts & Companies
The Experts below are selected from a list of 246 Experts worldwide ranked by ideXlab platform
Cheng Wang – One of the best experts on this subject based on the ideXlab platform.
Resonant Soft X-Ray scattering for polymer materialsEuropean Polymer Journal, 2016Co-Authors: Michael A. Brady, Cheng WangAbstract:
Abstract Resonant Soft X-Ray Scattering (RSoXS) was developed over the last a few years, and the first dedicated resonant Soft X-Ray scattering beamline for Soft materials was constructed at the Advanced Light Source, LBNL. RSoXS combines Soft X-Ray spectroscopy with X-Ray scattering and thus offers statistical information for 3D chemical morphology over a large length scale range from nanometers to micrometers. Using RSoXS to characterize multi-length scale Soft materials with heterogeneous chemical structures, we have demonstrated that Soft X-Ray scattering is a unique complementary technique to conventional hard X-Ray and neutron scattering. Its unique chemical sensitivity, large accessible size scale, molecular bond orientation sensitivity with polarized X-Rays, and high coherence have shown great potential for chemically specific structural characterization for many classes of materials.
Adam P. Hitchcock – One of the best experts on this subject based on the ideXlab platform.
Introduction of Soft X-Ray spectromicroscopy as an advanced technique for plant biopolymers researchPLoS ONE, 2015Co-Authors: Chithra Karunakaran, Colleen R. Christensen, Cedric Gaillard, Rachid Lahlali, Lisa M. Blair, Vijayan Perumal, Shea S. Miller, Adam P. HitchcockAbstract:
Soft X-Ray absorption spectroscopy coupled with nano-scale microscopy has been widely used in material science, environmental science, and physical sciences. In this work, the advantages of Soft X-Ray absorption spectromicroscopy for plant biopolymer research were demonstrated by determining the chemical sensitivity of the technique to identify common plant biopolymers and to map the distributions of biopolymers in plant samples. The chemical sensitivity of Soft X-Ray spectroscopy to study biopolymers was determined by recording the spectra of common plant biopolymers using Soft X-Ray and Fourier Transform mid Infrared (FT-IR) spectroscopy techniques. The Soft X-Ray spectra of lignin, cellulose, and polygalacturonic acid have distinct spectral features. However, there were no distinct differences between cellulose and hemicellulose spectra. Mid infrared spectra of all biopolymers were unique and there were differences between the spectra of water soluble and insoluble xylans. The advantage of nano-scale spatial resolution exploited using Soft X-Ray spectromicroscopy for plant biopolymer research was demonstrated by mapping plant cell wall biopolymers in a lentil stem section and compared with the FT-IR spectromicroscopy data from the same sample. The Soft X-Ray spectromicroscopy enables mapping of biopolymers at the sub-cellular (similar to 30 nm) resolution whereas, the limited spatial resolution in the micron scale range in the FT-IR spectromicroscopy made it difficult to identify the localized distribution of biopolymers. The advantages and limitations of Soft X-Ray and FT-IR spectromicroscopy techniques for biopolymer research are also discussed.
Soft X-Ray spectromicroscopy and ptychographyJournal of Electron Spectroscopy and Related Phenomena, 2015Co-Authors: Adam P. HitchcockAbstract:
Abstract Instrumentation and current capabilities of Soft X-Ray (50–2000 eV) spectromicroscopy are outlined with examples from recently published and some new work. Four common techniques are treated—transmission X-Ray microscopy (TXM), scanning transmission X-Ray microscopy (STXM), X-Ray photoemission electron microscopy (XPEEM) and scanning photoemission microscopy (SPEM). I also present a fifth, emerging technique, that of Soft X-Ray spectro-ptychography which has significantly improved spatial resolution and provides new contrast mechanisms. Perspectives for near future (5–10 years) evolution of Soft X-Ray spectromicroscopy are outlined based on current trends and instrumentation under development.
Zone plate focused Soft X-Ray lithographyApplied Physics A, 2011Co-Authors: Adam F. G. Leontowich, Adam P. HitchcockAbstract:
The zone plate focused Soft X-Rays of a scanning transmission X-Ray microscope have been used to pattern poly(methyl methacrylate) and poly(dimethylglutarimide) films by a direct write method which is analogous to lithography with a focused electron beam. The lithographic characteristics of both polymers have been determined for 300 eV X-Rays. With low doses (1 MGy), developed lines 40±5 nm wide were created in poly(methyl methacrylate). At higher doses an exposure spreading phenomenon substantially increases the lateral dimensions of the developed patterns. The spreading mechanism has been identified as the point-spread function of the zone plate lens. The performance of focused Soft X-Ray lithography is compared to other direct write methods. The practicality of a dedicated focused Soft X-Ray writer instrument is discussed.
Sophie Kazamias – One of the best experts on this subject based on the ideXlab platform.
Fourier-limited seeded Soft X-Ray laser pulseOptics Letters, 2010Co-Authors: O Guilbaud, F. Tissandier, Jean-philippe Goddet, Maxime Ribière, Stéphane Sebban, Julien Gautier, Denis Joyeux, D Ros, K Cassou, Sophie KazamiasAbstract:
We present what we believe to be the first measurement of the spectral properties of a Soft X-Ray laser seeded by a high-order harmonic beam. Using an interferometric method, the spectral profile of a seeded Ni-like krypton Soft X-Ray laser (32.8 nm) generated by optical field ionization has been experimentally determined, and the shortest possible pulse duration has been deduced. The source exhibits a Voigt spectral profile with an FWHM of 3.1±0.3 mÅ, leading to a Fourier-transform pulse duration of 4.7 ps. This value is comparable with the upper limit of the Soft X-Ray pulse duration determined by experimentally investigating the gain dynamics, from which we conclude that the source has reached the Fourier limit. The measured bandwidth is in good agreement with the predictions of a radiative transfer code, including gain line narrowing and saturation rebroadening.
Homogeneous focusing with a transient Soft X-Ray laser for irradiations experimentsOptics Communications, 2006Co-Authors: Sophie Kazamias, K Cassou, Annie Klisnick, David Ros, Olivier Guilbaud, Fabien Ple, Gérard Jamelot, Bedrich Rus, M. Koslova, M. StupkaAbstract:
We report the work done on a transient Soft X-Ray laser (SXRL) beam to deliver a proper extreme UV irradiation source for applications. The same optical tool was first demonstrated on a quasi stationnary state (QSS) Soft X-Ray laser at the PALS Institute in Prague. The problem set by the transient Soft X-Ray laser developed by the LIXAM at the LULI installation in Palaiseau is more crucial, first because the beam spatial profile is more irregular secondly because high repetition rate Soft X-Ray laser facilities in the future are based on this SXRL type. The spots obtained show a 20 micron average diameter and a rather homogeneous and smooth profile that make them a realistic irradiation source to interact with targets requiring relatively high fluence (near 1 J/cm2) or intensity (near 1011 W/cm2) in the extreme UV domain.