High-Resolution High-Count-Rate X-ray Spectroscopy with State-of-the-Art Silicon Detectors

1998 ◽  
Vol 5 (3) ◽  
pp. 268-274 ◽  
Author(s):  
L. Strüder ◽  
C. Fiorini ◽  
E. Gatti ◽  
R. Hartmann ◽  
P. Holl ◽  
...  
Keyword(s):  
Count Rate ◽  
Room Temperature ◽  
Single Photon ◽  
Low Noise ◽  
Light Sources ◽  
X Rays ◽  
X Ray ◽  
Synchrotron Light ◽  
On Chip ◽  
Synchrotron Light Sources

For the European X-ray multi-mirror (XMM) satellite mission and the German X-ray satellite ABRIXAS, fully depleted pn-CCDs have been fabricated, enabling high-speed low-noise position-resolving X-ray spectroscopy. The detector was designed and fabricated with a homogeneously sensitive area of 36 cm2. At 150 K it has a noise of 4 e− r.m.s., with a readout time of the total focal plane array of 4 ms. The maximum count rate for single-photon counting was 105 counts s−1 under flat-field conditions. In the integration mode more than 109 counts s−1 can be detected at 6 keV. Its position resolution is of the order of 100 µm. The quantum efficiency is higher than 90% from carbon K X-rays (277 eV) up to 10 keV. New cylindrical silicon drift detectors have been designed, fabricated and tested. They comprise an integrated on-chip amplifier system with continuous reset, on-chip voltage divider, electron accumulation layer stabilizer, large area, homogeneous radiation entrance window and a drain for surface-generated leakage current. At count rates as high as 2 × 106 counts cm−2 s−1, they still show excellent spectroscopic behaviour at room-temperature operation in single-photon detection mode. The energy resolution at room temperature is 220 eV at 6 keV X-ray energy and 140 eV at 253 K, being achieved with Peltier coolers. These systems were operated at synchrotron light sources (ESRF, HASYLAB and NLS) as X-ray fluorescence spectrometers in scanning electron microscopes and as ultra low noise photodiodes. The operation of a multi-channel silicon drift detector system is already foreseen at synchrotron light sources for X-ray holography experiments. All systems are fabricated in planar technology having the detector and amplifiers monolithically integrated on high-resistivity silicon.

High-Resolution X-ray Spectroscopy Close to Room Temperature

1998 ◽  
Vol 4 (6) ◽  
pp. 622-631 ◽  
Author(s):  
L. Strüder ◽  
N. Meidinger ◽  
D. Stotter ◽  
J. Kemmer ◽  
P. Lechner ◽  
...  
Keyword(s):  
High Resolution ◽  
Count Rate ◽  
High Speed ◽  
Room Temperature ◽  
Single Photon ◽  
Low Noise ◽  
Detector System ◽  
Wide Field ◽  
X Rays ◽  
X Ray

Originally designed as position-sensitive detectors for particle tracking, silicon drift detectors (SDDs) are now used for high-count rate X-ray spectroscopy, operating close to room temperature. Their low-capacitance read-node concept places them among the fastest high-resolution detector systems. They have been used in a new spectrum of experiments in the wide field of X-ray spectroscopy: fluorescent analysis, diffrac-tometry, materials analysis, and synchrotron experiments such as X-ray holography and element imaging in scanning electron microscopes. The fact that the detector system can be used at room temperature with good spectroscopic performance and at −10°C with excellent energy resolution, avoiding liquid nitrogen for cooling and high-quality vacuum, guarantees a large variety of new applications, independent of the laboratory environment. A brief description of the device principles is followed by basics on low noise amplification. The performance results of a complete detector system are presented as well as some dedicated applications already realized, including use in a surface mapping instrument and use of a “mini-spectrometer” for the analysis of works of art. Fully depleted pn-charge-coupled devices (pn-CCDs) have been fabricated for the European X-ray Multi-Mirror mission (XMM) and the German X-ray satellite ABRIXAS, enabling high-speed, low-noise, position-resolving X-ray spectroscopy. The detector was designed and fabricated with a homogeneously sensitive area of 36 cm2. At −70°C it has a noise of 4 e- rms, with a readout time of the total focal plane array of 4 msec. The maximum count rate for single photon counting was 105 cps under flat field conditions. In the integration mode, more than 109 cps can be detected at 6 keV. Its position resolution is on the order of 100 μm. The quantum efficiency is higher than 90%, ranging from carbon K X-rays (277 eV) up to 10 keV.

scholarly journals Anaerobic fixed-target serial crystallography

IUCrJ ◽  
2020 ◽  
Vol 7 (5) ◽  
pp. 901-912
Author(s):  
Patrick Rabe ◽  
John H. Beale ◽  
Agata Butryn ◽  
Pierre Aller ◽  
Anna Dirr ◽  
...  
Keyword(s):  
Data Collection ◽  
Room Temperature ◽  
Temperature Data ◽  
Protein Crystal ◽  
Light Sources ◽  
Strictly Anaerobic ◽  
X Ray ◽  
Synchrotron Light ◽  
Synchrotron Light Sources ◽  
Anaerobic Environment

Cryogenic X-ray diffraction is a powerful tool for crystallographic studies on enzymes including oxygenases and oxidases. Amongst the benefits that cryo-conditions (usually employing a nitrogen cryo-stream at 100 K) enable, is data collection of dioxygen-sensitive samples. Although not strictly anaerobic, at low temperatures the vitreous ice conditions severely restrict O2 diffusion into and/or through the protein crystal. Cryo-conditions limit chemical reactivity, including reactions that require significant conformational changes. By contrast, data collection at room temperature imposes fewer restrictions on diffusion and reactivity; room-temperature serial methods are thus becoming common at synchrotrons and XFELs. However, maintaining an anaerobic environment for dioxygen-dependent enzymes has not been explored for serial room-temperature data collection at synchrotron light sources. This work describes a methodology that employs an adaptation of the `sheet-on-sheet' sample mount, which is suitable for the low-dose room-temperature data collection of anaerobic samples at synchrotron light sources. The method is characterized by easy sample preparation in an anaerobic glovebox, gentle handling of crystals, low sample consumption and preservation of a localized anaerobic environment over the timescale of the experiment (<5 min). The utility of the method is highlighted by studies with three X-ray-radiation-sensitive Fe(II)-containing model enzymes: the 2-oxoglutarate-dependent L-arginine hydroxylase VioC and the DNA repair enzyme AlkB, as well as the oxidase isopenicillin N synthase (IPNS), which is involved in the biosynthesis of all penicillin and cephalosporin antibiotics.

scholarly journals Short X-ray pulses from third-generation light sources

2016 ◽  
Vol 23 (1) ◽  
pp. 141-151 ◽  
Author(s):  
A. G. Stepanov ◽  
C. P. Hauri
Keyword(s):  
Large Scale ◽  
Light Sources ◽  
Third Generation ◽  
Time Duration ◽  
Pulse Emission ◽  
Time Resolved ◽  
High Brightness ◽  
X Ray ◽  
Synchrotron Light ◽  
Synchrotron Light Sources

High-brightness X-ray radiation produced by third-generation synchrotron light sources (TGLS) has been used for numerous time-resolved investigations in many different scientific fields. The typical time duration of X-ray pulses delivered by these large-scale machines is about 50–100 ps. A growing number of time-resolved studies would benefit from X-ray pulses with two or three orders of magnitude shorter duration. Here, techniques explored in the past for shorter X-ray pulse emission at TGLS are reviewed and the perspective towards the realisation of picosecond and sub-picosecond X-ray pulses are discussed.

scholarly journals Diffuse scattering and partial disorder in complex structures

IUCrJ ◽  
2014 ◽  
Vol 1 (6) ◽  
pp. 550-562 ◽  
Author(s):  
T. R. Welberry ◽  
D. J. Goossens
Keyword(s):  
Diffuse Scattering ◽  
Three Dimensional ◽  
Low Noise ◽  
Light Sources ◽  
X Ray Crystallography ◽  
Short Range Ordering ◽  
Noise Data ◽  
Quantitative Analyses ◽  
Synchrotron Light ◽  
Synchrotron Light Sources

The study of single-crystal diffuse scattering (SCDS) goes back almost to the beginnings of X-ray crystallography. Because SCDS arises from two-body correlations, it contains information about local (short-range) ordering in the sample, information which is often crucial in the attempt to relate structure to function. This review discusses the state of the field, including detectors and data collection and the modelling of SCDS using Monte Carlo andab initiotechniques. High-quality, three-dimensional volumes of SCDS data can now be collected at synchrotron light sources, allowing ever more detailed and quantitative analyses to be undertaken, and opening the way to approaches such as three-dimensional pair distribution function studies (3D-PDF) and automated refinement of a disorder model, powerful techniques that require large volumes of low-noise data.

scholarly journals A Rebirth of Laboratory XANES and XES

2014 ◽  
Vol 70 (a1) ◽  
pp. C222-C222
Author(s):  
Gerald Seidler ◽  
Devon Mortensen ◽  
Joseph Pacold ◽  
Oliver Hoidn
Keyword(s):  
High Resolution ◽  
Energy Range ◽  
Emission Spectroscopy ◽  
Light Sources ◽  
Edge Structure ◽  
X Ray ◽  
Insertion Device ◽  
Synchrotron Light ◽  
Synchrotron Light Sources ◽  
X Ray Absorption

We have recently launched a reinvestigation of laboratory-based measurement of x-ray absorption near edge structure (XANES) and high-resolution x-ray emission spectroscopy (XES). Driven by the roughly one-hundred-fold improvement in the efficiency of high resolution x-ray optics compared to the 1970's, we have demonstrated that surprisingly impressive performance is now possible with laboratory XES instruments and that quite useful performance is possible for laboratory XANES. For applications in the 5 keV- 10 keV energy range, i.e., appropriate for 3d transition metal K edges and lanthanide L edges, we find XES performance that is intermediate between what can be achieved at bending-magnet and insertion-device beamlines at third generation synchrotron light sources. In the same energy range, we find that high quality XANES measurements can be performed in transmission mode on concentrated samples with the present instrument and should be possible, in many cases, in fluorescence mode after a planned upgrade brings the monochromatic beam flux up to approximately 10M/sec.

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