A SOFT X-RAY UNDULATOR BEAMLINE AT THE ADVANCED LIGHT SOURCE WITH CIRCULAR AND VARIABLE LINEAR POLARIZATION FOR THE SPECTROSCOPY AND MICROSCOPY OF MAGNETIC MATERIALS

2002 ◽  
Vol 09 (01) ◽  
pp. 549-554 ◽  
Author(s):  
ANTHONY T. YOUNG ◽  
ELKE ARENHOLZ ◽  
JUN FENG ◽  
HOWARD PADMORE ◽  
STEVE MARKS ◽  
...  
Keyword(s):  
Light Source ◽  
National Laboratory ◽  
X Rays ◽  
X Ray ◽  
Advanced Light Source ◽  
Linearly Polarized ◽  
Linearly Polarized Radiation ◽  
Elliptically Polarized ◽  
Photoemission Electron ◽  
Polarized Radiation

A new undulator beamline at the Advanced Light Source, Lawrence Berkeley National Laboratory is described. This new beamline has an Apple II type undulator which produces linearly and elliptically polarized X-rays. A high resolution monochromator directs the radiation to two branchlines. The first branchline is optimized for spectroscopy and accommodates multiple endstations simultaneously. The second branchline features a photoemission electron microscope. A novel feature of the beamline is the ability to produce linearly polarized radiation at arbitrary, user-selectable angles. Applications of the new beamline are also described.

scholarly journals Biological soft X-ray tomography on beamline 2.1 at the Advanced Light Source

2014 ◽  
Vol 21 (6) ◽  
pp. 1370-1377 ◽  
Author(s):  
Mark A. Le Gros ◽  
Gerry McDermott ◽  
Bertrand P. Cinquin ◽  
Elizabeth A. Smith ◽  
Myan Do ◽  
...  
Keyword(s):  
Data Collection ◽  
Light Source ◽  
Mammalian Cells ◽  
National Laboratory ◽  
Three Dimensional ◽  
Imaging Method ◽  
X Rays ◽  
X Ray ◽  
Correlative Imaging ◽  
Advanced Light Source

Beamline 2.1 (XM-2) is a transmission soft X-ray microscope in sector 2 of the Advanced Light Source at Lawrence Berkeley National Laboratory. XM-2 was designed, built and is now operated by the National Center for X-ray Tomography as a National Institutes of Health Biomedical Technology Research Resource. XM-2 is equipped with a cryogenic rotation stage to enable tomographic data collection from cryo-preserved cells, including large mammalian cells. During data collection the specimen is illuminated with `water window' X-rays (284–543 eV). Illuminating photons are attenuated an order of magnitude more strongly by biomolecules than by water. Consequently, differences in molecular composition generate quantitative contrast in images of the specimen. Soft X-ray tomography is an information-rich three-dimensional imaging method that can be applied either as a standalone technique or as a component modality in correlative imaging studies.

scholarly journals Linearly polarized X-ray fluorescence computed tomography based on a Thomson scattering light source: a Monte Carlo study

2020 ◽  
Vol 27 (3) ◽  
pp. 737-745
Author(s):  
Zhijun Chi ◽  
Yingchao Du ◽  
Wenhui Huang ◽  
Chuanxiang Tang
Keyword(s):  
Computed Tomography ◽  
Monte Carlo ◽  
Compton Scattering ◽  
Light Source ◽  
Thomson Scattering ◽  
X Rays ◽  
X Ray ◽  
Pile Up ◽  
Linearly Polarized ◽  
Scattering Light

A Thomson scattering X-ray source can provide quasi-monochromatic, continuously energy-tunable, polarization-controllable and high-brightness X-rays, which makes it an excellent tool for X-ray fluorescence computed tomography (XFCT). In this paper, we examined the suppression of Compton scattering background in XFCT using the linearly polarized X-rays and the implementation feasibility of linearly polarized XFCT based on this type of light source, concerning the influence of phantom attenuation and the sampling strategy, its advantage over K-edge subtraction computed tomography (CT), the imaging time, and the potential pulse pile-up effect by Monte Carlo simulations. A fan beam and pinhole collimator geometry were adopted in the simulation and the phantom was a polymethyl methacrylate cylinder inside which were gadolinium (Gd)-loaded water solutions with Gd concentrations ranging from 0.2 to 4.0 wt%. Compared with the case of vertical polarization, Compton scattering was suppressed by about 1.6 times using horizontal polarization. An accurate image of the Gd-containing phantom was successfully reconstructed with both spatial and quantitative identification, and good linearity between the reconstructed value and the Gd concentration was verified. When the attenuation effect cannot be neglected, one full cycle (360°) sampling and the attenuation correction became necessary. Compared with the results of K-edge subtraction CT, the contrast-to-noise ratio values of XFCT were improved by 2.03 and 1.04 times at low Gd concentrations of 0.2 and 0.5 wt%, respectively. When the flux of a Thomson scattering light source reaches 1013 photons s−1, it is possible to finish the data acquisition of XFCT at the minute or second level without introducing pulse pile-up effects.

scholarly journals Implementation and performance of SIBYLS: a dual endstation small-angle X-ray scattering and macromolecular crystallography beamline at the Advanced Light Source

2013 ◽  
Vol 46 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Scott Classen ◽  
Greg L. Hura ◽  
James M. Holton ◽  
Robert P. Rambo ◽  
Ivan Rodic ◽  
...  
Keyword(s):  
Data Collection ◽  
Light Source ◽  
Small Angle ◽  
National Laboratory ◽  
Department Of Energy ◽  
Macromolecular Crystallography ◽  
X Ray ◽  
X Ray Scattering ◽  
Advanced Light Source ◽  
Ray Scattering

The SIBYLS beamline (12.3.1) of the Advanced Light Source at Lawrence Berkeley National Laboratory, supported by the US Department of Energy and the National Institutes of Health, is optimized for both small-angle X-ray scattering (SAXS) and macromolecular crystallography (MX), making it unique among the world's mostly SAXS or MX dedicated beamlines. Since SIBYLS was commissioned, assessments of the limitations and advantages of a combined SAXS and MX beamline have suggested new strategies for integration and optimal data collection methods and have led to additional hardware and software enhancements. Features described include a dual mode monochromator [containing both Si(111) crystals and Mo/B4C multilayer elements], rapid beamline optics conversion between SAXS and MX modes, active beam stabilization, sample-loading robotics, and mail-in and remote data collection. These features allow users to gain valuable insights from both dynamic solution scattering and high-resolution atomic diffraction experiments performed at a single synchrotron beamline. Key practical issues considered for data collection and analysis include radiation damage, structural ensembles, alternative conformers and flexibility. SIBYLS develops and applies efficient combined MX and SAXS methods that deliver high-impact results by providing robust cost-effective routes to connect structures to biology and by performing experiments that aid beamline designs for next generation light sources.

Polarization Aspects of Localized Optical Spots Obtained Using Plasmonic Nano-Antennas

2010 ◽  
Vol 1248 ◽  
Author(s):  
Erdem Ogut ◽  
Kursat Sendur
Keyword(s):  
Electromagnetic Radiation ◽  
Incident Light ◽  
Diffraction Limit ◽  
Stokes Parameters ◽  
Polarization Angle ◽  
All Optical ◽  
Linearly Polarized ◽  
Linearly Polarized Radiation ◽  
Elliptically Polarized ◽  
Polarized Radiation

AbstractElectromagnetic radiation beyond the diffraction limit with a particular polarization emerges as a need for plasmonic applications. One of these applications is all-optical magnetic recording, which requires circularly-polarized electromagnetic radiation. In this study, a plasmonic cross-dipole nano-antenna is illuminated with diffraction-limited linearly polarized radiation. An optimal configuration for the nano-antenna and the polarization angle of the incident light is identified to obtain linearly, circularly, and elliptically polarized optical spots beyond the diffraction limit. The Poincaré sphere representation is utilized to visually present calculated Stokes parameters for optical spots with linear, circular, and elliptical polarizations from specific antenna geometries.

High-Resolution X-Ray Photoemission Electron Microscopy at the Advanced Light Source

1998 ◽  
Vol 524 ◽  
Author(s):  
Thomas Stammler ◽  
Simone Anders ◽  
Howard A. Padmore ◽  
Joachim Stöhr ◽  
Michael Scheinfein ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Light Source ◽  
Field Emission ◽  
Spatial Resolution ◽  
Experimental Program ◽  
Photoemission Electron Microscopy ◽  
X Ray ◽  
Advanced Light Source ◽  
Materials Research ◽  
Photoemission Electron

ABSTRACTX-ray Photoemission Electron Microscopy (X-PEEM) is a full-field imaging technique where the sample is illuminated by an x-ray beam and the photoemitted electrons are imaged on a screen by means of an electron optics. It therefore combines two well-established materials analysis techniques - photoemission electron microscopy (PEEM) and x-ray spectroscopy such as near edge x-ray absorption fine structure (NEXAFS) spectroscopy. This combination opens a wide field of new applications in materials research and has proven to be a powerful tool to investigate simultaneously topological, elemental, chemical state, and magnetic properties of surfaces, thin films, and multilayers at high spatial resolution. A new X-PEEM installed at the bend magnet beamline 7.3.1.1 at the Advanced Light Source (ALS) is designed for a spatial resolution of 20 nm and is currently under commissioning. An overview of the ongoing experimental program using X-PEEM in the field of materials research at the ALS is given by elemental and chemical bonding contrast imaging of hard disk coatings and sliders, field emission studies on diamond films as possible candidates for field-emission flat-panel displays, and the study of dewetting and decomposition phenomena of thin polymer blends and bilayers.

scholarly journals High Pressure Diffraction for the Geosciences at the Advanced Light Source

2014 ◽  
Vol 70 (a1) ◽  
pp. C1097-C1097
Author(s):  
Christine Beavers ◽  
Jason Knight ◽  
Bora Kalkan ◽  
Jinyuan Yan ◽  
Alastair MacDowell ◽  
...  
Keyword(s):  
High Pressure ◽  
Light Source ◽  
High Pressures ◽  
X Rays ◽  
X Ray Diffraction ◽  
User Friendliness ◽  
X Ray ◽  
Advanced Light Source ◽  
Diamond Anvil ◽  
Multiple Detectors

The Advanced Light Source, in concert with COMPRES, supports a superconducting bending magnet beamline devoted to extreme conditions diffraction. This facility, beamline 12.2.2, is aimed at the geoscience community, but is available to any who desire high pressures, high temperatures and hard X-rays. The latest development has been integrating single crystal x-ray diffraction for diamond anvil cells into the existing suite of high pressure powder diffraction and amorphous scattering techniques. Multiple heating techniques are available to the user, as well as multiple detectors, which can be chosen to best suit the sample. The current staff are dedicated to improving the user friendliness of the beamline; a difficult experiment need not to be further complicated by a difficult beamline. Beamline infrastructure, including recent advances and improvements, will be discussed.

Anisotropic angular distribution of Er L x-rays following photoionization by linearly polarized radiation

2005 ◽  
Vol 38 (7) ◽  
pp. 839-852 ◽  
Author(s):  
Raul A Barrea ◽  
Carlos A Pérez ◽  
Tomás S Plivelic ◽  
Edgardo V Bonzi ◽  
Héctor J Sánchez
Keyword(s):  
Angular Distribution ◽  
X Rays ◽  
Linearly Polarized ◽  
Linearly Polarized Radiation ◽  
Polarized Radiation

scholarly journals A cantilevered liquid-nitrogen-cooled silicon mirror for the Advanced Light Source Upgrade

2020 ◽  
Vol 27 (5) ◽  
pp. 1131-1140 ◽  
Author(s):  
Grant Cutler ◽  
Daniele Cocco ◽  
Elaine DiMasi ◽  
Simon Morton ◽  
Manuel Sanchez del Rio ◽  
...  
Keyword(s):  
Liquid Nitrogen ◽  
Light Source ◽  
National Laboratory ◽  
Lawrence Berkeley National Laboratory ◽  
Strehl Ratio ◽  
X Ray ◽  
Polarization Control ◽  
Insertion Device ◽  
Entire Energy ◽  
Advanced Light Source

This paper presents a novel cantilevered liquid-nitrogen-cooled silicon mirror design for the first optic in a new soft X-ray beamline that is being developed as part of the Advanced Light Source Upgrade (ALS-U) (Lawrence Berkeley National Laboratory, USA). The beamline is optimized for photon energies between 400 and 1400 eV with full polarization control. Calculations indicate that, without correction, this design will achieve a Strehl ratio greater than 0.85 for the entire energy and polarization ranges of the beamline. With a correction achieved by moving the focus 7.5 mm upstream, the minimum Strehl ratio is 0.99. This design is currently the baseline plan for all new ALS-U insertion device beamlines.

X-ray microscopy by phase-retrieval methods at the advanced light source

2003 ◽  
Vol 104 ◽  
pp. 557-561 ◽  
Author(s):  
M. R. Howells ◽  
H. Chapman ◽  
S. Hau-Riege ◽  
H. He ◽  
S. Marchesini ◽  
...  
Keyword(s):  
Light Source ◽  
Phase Retrieval ◽  
X Ray ◽  
Advanced Light Source
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