scholarly journals Scanning Transmission X-Ray Microscopy in the Soft Energy Range with Very Large Solid Angle of Detection for X-ray Fluorescence Imaging

2018 ◽  
Vol 24 (S2) ◽  
pp. 86-87
Author(s):  
L. Luhl ◽  
K. Andrianov ◽  
A. Haidl ◽  
H. Dierks ◽  
A. Dehlinger ◽  
...  
Keyword(s):  
Energy Range ◽  
Fluorescence Imaging ◽  
Solid Angle ◽  
X Ray ◽  
Scanning Transmission

scholarly journals Scanning transmission X-ray microscopy with efficient X-ray fluorescence detection (STXM-XRF) for biomedical applications in the soft and tender energy range

2019 ◽  
Vol 26 (2) ◽  
pp. 430-438 ◽  
Author(s):  
Lars Lühl ◽  
Konstantin Andrianov ◽  
Hanna Dierks ◽  
Andreas Haidl ◽  
Aurelie Dehlinger ◽  
...  
Keyword(s):  
Energy Range ◽  
Fluorescence Detection ◽  
Biomedical Applications ◽  
Solid Angle ◽  
Fluorescence Yield ◽  
Fluorescence Signal ◽  
X Ray ◽  
Elemental Imaging ◽  
Scanning Transmission ◽  
Biochemical Mechanisms

Scanning transmission X-ray microscopy, especially in combination with X-ray fluorescence detection (STXM-XRF) in the soft X-ray energy range, is becoming an increasingly important tool for life sciences. Using X-ray fluorescence detection, the study of biochemical mechanisms becomes accessible. As biological matrices generally have a low fluorescence yield and thus a low fluorescence signal, high detector efficiency (e.g. large solid angle) is indispensable for avoiding long measurement times and radiation damage. Here, the new AnImaX STXM-XRF microscope equipped with a large solid angle of detection enabling fast scans and the first proof-of-principle measurements on biomedical samples are described. In addition, characterization measurements for future quantitative elemental imaging are presented.

A scanning transmission X-ray microscope at the Pohang Light Source

2018 ◽  
Vol 25 (3) ◽  
pp. 878-884 ◽  
Author(s):  
Hyun-Joon Shin ◽  
Namdong Kim ◽  
Hee-Seob Kim ◽  
Wol-Woo Lee ◽  
Chae-Soon Lee ◽  
...  
Keyword(s):  
Energy Range ◽  
Light Source ◽  
Photon Energy ◽  
Chemical State ◽  
Photon Energy Range ◽  
X Rays ◽  
X Ray ◽  
Space Resolution ◽  
Scanning Transmission ◽  
Pohang Light Source

A scanning transmission X-ray microscope is operational at the 10A beamline at the Pohang Light Source. The 10A beamline provides soft X-rays in the photon energy range 100–2000 eV using an elliptically polarized undulator. The practically usable photon energy range of the scanning transmission X-ray microscopy (STXM) setup is from ∼150 to ∼1600 eV. With a zone plate of 25 nm outermost zone width, the diffraction-limited space resolution, ∼30 nm, is achieved in the photon energy range up to ∼850 eV. In transmission mode for thin samples, STXM provides the element, chemical state and magnetic moment specific distributions, based on absorption spectroscopy. A soft X-ray fluorescence measurement setup has been implemented in order to provide the elemental distribution of thicker samples as well as chemical state information with a space resolution of ∼50 nm. A ptychography setup has been implemented in order to improve the space resolution down to 10 nm. Hardware setups and application activities of the STXM are presented.

Analytical Formulae for Calculation of X-Ray Detector Solid Angles in the Scanning and Scanning/Transmission Analytical Electron Microscope

2014 ◽  
Vol 20 (4) ◽  
pp. 1318-1326 ◽  
Author(s):  
Nestor J. Zaluzec
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Solid Angle ◽  
Analytical Electron Microscopy ◽  
X Ray ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
Scanning Transmission ◽  
Analytical Formulae ◽  
Detector Configurations

AbstractClosed form analytical equations used to calculate the collection solid angle of six common geometries of solid-state X-ray detectors in scanning and scanning/transmission analytical electron microscopy are presented. Using these formulae one can make realistic comparisons of the merits of the different detector geometries in modern electron column instruments. This work updates earlier formulations and adds new detector configurations.

Quantitative Analysis of Atomic-Resolution X-ray Maps in an Aberration- Corrected Scanning Transmission Electron Microscope with a Large Solid- Angle Detector

2012 ◽  
Vol 18 (S2) ◽  
pp. 974-975 ◽  
Author(s):  
M. Watanabe ◽  
A. Yasuhara ◽  
E. Okunishi
Keyword(s):  
Electron Microscope ◽  
Quantitative Analysis ◽  
Transmission Electron Microscope ◽  
Solid Angle ◽  
Scanning Transmission Electron Microscope ◽  
Atomic Resolution ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Aberration Corrected

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.

Quantitative Assessment and Measurement of X-ray Detector Performance and Solid Angle in the Analytical Electron Microscope

2021 ◽  
pp. 1-13
Author(s):  
Nestor J. Zaluzec
Keyword(s):  
Solid Angle ◽  
Collection Efficiency ◽  
Analytical Formula ◽  
Individual Performance ◽  
Detector Performance ◽  
X Ray ◽  
Wide Range ◽  
Analytical Electron ◽  
Scanning Transmission ◽  
Electron Microscopes

A wide range of X-ray detectors and geometries are available today on transmission/scanning transmission analytical electron microscopes. While there have been numerous reports of their individual performance, no single experimentally reproducible metric has been proposed as a basis of comparison between the systems. In this paper, we detail modeling, experimental procedures, measurements, and specimens which can be used to provide a manufacturer-independent assessment of the performance of an analytical system. Using these protocols, the geometrical collection efficiency, system peaks, and minimum detection limits can be independently assessed and can be used to determine the best conditions to conduct modern hyperspectral and/or spectrally resolved tomographic analyses for an individual instrument. A simple analytical formula and specimen is presented which after suitable system calibrations can be used to experimentally determine the X-ray detector solid angle.

The TES beamline (8-BM) at NSLS-II: tender-energy spatially resolved X-ray absorption spectroscopy and X-ray fluorescence imaging

2019 ◽  
Vol 26 (6) ◽  
pp. 2064-2074 ◽  
Author(s):  
Paul Northrup
Keyword(s):  
Energy Range ◽  
Fluorescence Imaging ◽  
Absorption Spectroscopy ◽  
Small Sample ◽  
Energy Calibration ◽  
Helium Atmosphere ◽  
X Ray ◽  
Spatially Resolved ◽  
X Ray Absorption

The tender-energy X-ray spectroscopy (TES) beamline at the National Synchrotron Light Source II (NSLS-II) is now operational for general users. Its scientific mission includes static and in situ X-ray fluorescence imaging and spatially resolved X-ray absorption spectroscopy for characterization of complex heterogeneous, structured and dynamic natural or engineered materials and systems. TES is optimized for the tender-energy range, offering routine operations from 2.0 to 5.5 keV, with capabilities to reach down to 1.2 or up to 8 keV with configuration change. TES is designed as an extended X-ray absorption fine-structure microprobe (EXAFS microprobe) for applications of micrometre-scale EXAFS spectroscopy to heterogeneous samples. Beam size is user-tunable from ∼2 to 25 µm. Energy may be scanned on-the-fly or in traditional step scanning. Importantly, the position of the microbeam at the sample location does not move significantly during energy scanning or when changing energy across the entire routine energy range. This enables full EXAFS of a particle or domain the same size as the probe beam, and measurement of the same spot at different energies. In addition, there is no measureable drift in energy calibration (repeatability) scan-to-scan and over 24 h. This is critical where simultaneous calibration measurements are generally not feasible, and for speciation mapping where precise and stable control of incident energy is essential. The sample environment is helium atmosphere at room pressure with infrastructure for in situ electrochemistry and catalysis in small sample cells or microreactors. As the first bend-magnet beamline at NSLS-II, noteworthy commissioning aspects are described. Example measurements are presented to illustrate its capabilities.

A comparison of two windowless x-ray detector designs on VG HB501 STEMs

1988 ◽  
Vol 46 ◽  
pp. 672-673
Author(s):  
A. W. Nicholls
Keyword(s):  
Energy Range ◽  
Solid Angle ◽  
Low Energy ◽  
Original Design ◽  
X Ray ◽  
Solid Angles

Windowless X-ray detectors are routinely used on VG HB501 STEMs allowing detection of all elements from B upwards (fig 1). The original design for the HB501 built by Link Analytical had a theoretical solid angle of 0.077sr but recently a new design has appeared with a solid angle of 0.181sr. In order to compare these two designs it would be useful to develop a test that could be carried out on the microscope column that would accurately characterise the performance of the detector in the low energy range (<1keV) as well as at higher energies. Recently there has been much interest in characterising X-ray detector microscope systems using the peak to background (P' B) ratio from specially prepared evaporated Cr films. As an extension to this method this type of specimen has-been used to look at the ratio of effective detector solid angles and also the low energy area by comparing CrK to CrL intensities in order to fully characterise the detectors on VG HB501 STEMs.

Optimizing conditions for x-ray microchemical analysis in analytical electron microscopy

1978 ◽  
Vol 36 (1) ◽  
pp. 548-549 ◽  
Author(s):  
N. J. Zaluzec
Keyword(s):  
Solid Angle ◽  
Analytical Electron Microscopy ◽  
Incident Beam ◽  
Thin Foil ◽  
Experimental Conditions ◽  
X Ray ◽  
Microchemical Analysis ◽  
Analytical Electron ◽  
Image Position ◽  
Incident Beam Energy

The ultimate sensitivity of microchemical analysis using x-ray emission rests in selecting those experimental conditions which will maximize the measured peak-to-background (P/B) ratio. This paper presents the results of calculations aimed at determining the influence of incident beam energy, detector/specimen geometry and specimen composition on the P/B ratio for ideally thin samples (i.e., the effects of scattering and absorption are considered negligible). As such it is assumed that the complications resulting from system peaks, bremsstrahlung fluorescence, electron tails and specimen contamination have been eliminated and that one needs only to consider the physics of the generation/emission process.The number of characteristic x-ray photons (Ip) emitted from a thin foil of thickness dt into the solid angle dΩ is given by the well-known equation

Sign in / Sign up

Export Citation Format

Share Document