Characterization of an X-ray mirror mechanical bender for the European XFEL

2016 ◽  
Vol 23 (4) ◽  
pp. 855-860 ◽  
Author(s):  
Maurizio Vannoni ◽  
Idoia Freijo Martín ◽  
Harald Sinn
Keyword(s):  
Radius Of Curvature ◽  
Cylindrical Shape ◽  
Mirror Surface ◽  
Fizeau Interferometer ◽  
X Ray ◽  
Optical Setup ◽  
Long Term Stability ◽  
Large Aperture

One of the classical devices used to tune a mirror on an X-ray optical setup is a mechanical bender. This is often designed in such a way that the mirror is held with clamps on both ends; a motor is then used to put a torque on the clamps, inducing a cylindrical shape of the mirror surface. A mechanical bender with this design was recently characterized, to bend a 950 mm-long mirror up to a radius of curvature of 10 km. The characterization was performed using a large-aperture Fizeau interferometer with an angled incidence setup. Some particular and critical effects were investigated, such as calibration, hysteresis, twisting and long-term stability.

scholarly journals Characterization of a piezo bendable X-ray mirror

2016 ◽  
Vol 23 (1) ◽  
pp. 169-175 ◽  
Author(s):  
Maurizio Vannoni ◽  
Idoia Freijo Martín ◽  
Frank Siewert ◽  
Riccardo Signorato ◽  
Fan Yang ◽  
...  
Keyword(s):  
Full Scale ◽  
Optical Component ◽  
Fizeau Interferometer ◽  
X Ray ◽  
Large Aperture ◽  
Substrate Side ◽  
Side Face ◽  
Measuring Machine ◽  
Reflecting Surface

A full-scale piezo bendable mirror built as a prototype for an offset mirror at the European XFEL is characterized. The piezo ceramic elements are glued onto the mirror substrate, side-face on with respect to the reflecting surface. Using a nanometre optical component measuring machine and a large-aperture Fizeau interferometer, the mirror profile and influence functions were characterized, and further analysis was made to investigate the junction effect, hysteresis, twisting and reproducibility.

Structural characterization of free-standing gallium arsenide coiled membranes produced by micromachining

1999 ◽  
Vol 32 (1) ◽  
pp. 60-64
Author(s):  
Krishan Lal ◽  
S. Niranjana N. Goswami ◽  
J. Miao ◽  
H. L. Hartnagel
Keyword(s):  
High Resolution ◽  
Beam Width ◽  
Thin Strip ◽  
X Ray Diffraction ◽  
Free Standing ◽  
X Ray ◽  
Long Term Stability ◽  
Diffraction Peaks

High-resolution X-ray diffraction techniques have been employed successfully to evaluate crystalline quality and long-term stability of coiled membranes. The process of fabrication involves photolithography, implantation by 2 MeV N^{2+} ions inn-type GaAs substrates, followed by selective etching. A five-crystal X-ray diffractometer was employed in (+, −, +) setting with an Mo Kα1exploring beam for high-resolution X-ray diffractometry and topography experiments. The exploring-beam width was reduced to illuminate different segments of the coiled membrane. Diffraction curves recorded from the bulk crystal surrounding the sensor had a half width of 26 arcseconds, whereas the half widths from sensor segments were in the range ∼58 to ∼166 arcseconds. Different segments (particularly vertical ones) were identified from the observed angular separations between different diffraction peaks as well as from the shape of the diffraction peaks. It was found that different segments of the sensor were tilted with respect to one another and the tilt angles were in the range 15–212 arcseconds. High-resolution X-ray diffraction topographs recorded from (5\bar 11) and (400) diffracting planes revealed that the sides of the trough below the membrane created by etching are not vertical, but tapered. Also, there is a thin strip of crystal freely hanging over the tapered regions as a result of underetching. The surface of the cavity is uneven. The structural perfection of different membrane segments could also be ascertained from the contrast in topographs.

Longevity of Borehole and Shaft Sealing Materials: Characterization of Ancient Cement Based Building Materials

1983 ◽  
Vol 26 ◽  
Author(s):  
Christine A. Langton ◽  
Della M. Roy
Keyword(s):  
Nuclear Waste ◽  
Building Materials ◽  
Materials Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Long Term Stability ◽  
Sealing Materials ◽  
National Effort

ABSTRACTDurability and long-term stability of cements in plasters, mortars, and/or concretes utilized as borehole plugging and shaft sealing materials are of present concern in the national effort to isolate nuclear waste within deep geological repositories. The present study consists of an examination of selected ancient building materials and provides insights into the durability of certain ancient structures. These data were combined with knowledge obtained from the behavior of modern portland cements and natural materials to evaluate the potential for longevity of such materials in a borehole environment. Analyses were conducted by petrographic, SEM, chemical, and x-ray diffraction techniques.

Enhanced stability of conductive polyacetylene in ladder-like surface-grafted brushes

2016 ◽  
Vol 7 (36) ◽  
pp. 5664-5670 ◽  
Author(s):  
Michał Szuwarzyński ◽  
Karol Wolski ◽  
Szczepan Zapotoczny
Keyword(s):  
Term Stability ◽  
Long Term Stability ◽  
Enhanced Stability

Formation and characterization of polyacetylene-based brushes that exhibit exceptional long term stability in air is presented here.

scholarly journals A survey of short-term and long-term stability of tube parameters in a mammography unit

2014 ◽  
Vol 29 (4) ◽  
pp. 321-325
Author(s):  
Jovica Praskalo ◽  
Jasna Davidovic ◽  
Biljana Kocic ◽  
Monika Zivkovic ◽  
Svetlana Pejovic
Keyword(s):  
Screening Program ◽  
Short Term ◽  
X Ray ◽  
Term Stability ◽  
Long Term Stability ◽  
Mammography Screening Program ◽  
The Republic ◽  
Set Up ◽  
The Given

In order to set up a successful mammography screening program in the Republic of Srpska, a Siemens Mammomat 1000 X-ray machine was selected for analysis as the said mammography system is widely used in clinical practice. The variations in tube parameters (specific air kerma, high-voltage accuracy and reproducibility, linearity between exposure and dose exposure time) were monitored over a five-year period, from 2008 to 2012. In addition, due to observed daily fluctuations for chosen parameters, a series of measurements were performed three times a day within a single-month period (mainly October 2012). The goal of such an experimental set up is to assess short-term and long-term stability of tube parameters in the given mammography unit and to make a comparison between them. The present paper shows how an early detection of significant parameter fluctuations can help eliminate irregularities and optimize the performance of mammography systems.

scholarly journals Physics of Relativistic Jets on Sub-Milliarcsecond Scales

1984 ◽  
Vol 110 ◽  
pp. 207-214
Author(s):  
Martin J. Rees
Keyword(s):  
Energy Production ◽  
Galactic Nuclei ◽  
Primary Energy ◽  
Relativistic Jets ◽  
Short Term ◽  
X Ray ◽  
Long Term Stability ◽  
Extended Sources ◽  
Vlbi Data

The observed superluminal components have (deprojected) lengths of ~ 1020 cm, and imply relativistic bulk motions on these scales. There are, however, persuasive reasons for attributing the primary energy production to scales 1014–1015 cm. Moreover, the initial bifurcation and collimation must also be imposed on these small scales if the long-term stability of the jet axis in extended sources is due to the gyroscopic effect of a spinning black hole (Rees 1978). The issues I shall address in this talk are: how the jet gets from ~ 1015cm to ~ 1019 cm; and what VLBI data can tell us about the properties of galactic nuclei on scales below ~ 1019 cm — scales where optical and X-ray studies provide some evidence, but where there is no short-term hope of achieving spatial resolution.

Synthesis of Trilaminar Core–Shell Au/α-Fe2O3@SnO2Nanocomposites and their Application for Nonenzymatic Dopamine Electrochemical Sensing

NANO ◽  
2019 ◽  
Vol 14 (11) ◽  
pp. 1950138 ◽  
Author(s):  
Sai Zhang ◽  
Shijun Yue ◽  
Jiajia Li ◽  
Jianbin Zheng ◽  
Guojie Gao
Keyword(s):  
Electron Microscopy ◽  
High Sensitivity ◽  
Electrochemical Sensing ◽  
Synthesis Process ◽  
Core Shell ◽  
X Ray Diffraction ◽  
X Ray ◽  
Long Term Stability ◽  
Transmission Electron

Au nanoparticles anchored on core–shell [Formula: see text]-Fe2O3@SnO2 nanospindles were successfully constructed through hydrothermal synthesis process and used for fabricating a novel nonenzymatic dopamine (DA) sensor. The structure and morphology of the Au/[Formula: see text]-Fe2O3@SnO2 trilaminar nanohybrid film were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The electrochemical properties of the sensor were investigated by cyclic voltammetry and amperometry. The experimental results suggest that the composites have excellent catalytic property toward DA with a wide linear range from 0.5[Formula: see text][Formula: see text]M to 0.47[Formula: see text]mM, a low detection limit of 0.17[Formula: see text][Formula: see text]M (S/[Formula: see text]) and high sensitivity of 397.1[Formula: see text][Formula: see text]A[Formula: see text]mM[Formula: see text][Formula: see text]cm[Formula: see text]. In addition, the sensor exhibits long-term stability, good reproducibility and anti-interference.

scholarly journals Material Characterization of Magnetorheological Elastomers with Corroded Carbonyl Iron Particles: Morphological Images and Field-dependent Viscoelastic Properties

2019 ◽  
Vol 20 (13) ◽  
pp. 3311 ◽  
Author(s):  
Siti Aishah Binti Abdul Aziz ◽  
Saiful Amri Mazlan ◽  
Nur Azmah Nordin ◽  
Nor Azlin Nazira Abd Rahman ◽  
U Ubaidillah ◽  
...  
Keyword(s):  
Carbonyl Iron ◽  
Matrix Material ◽  
Rheological Characteristics ◽  
Iron Particles ◽  
Ambient Conditions ◽  
X Ray ◽  
Field Dependent ◽  
Mr Effect

High temperatures and humidity could alter the field-dependent rheological properties of MR materials. These environmental phenomena may accelerate the deterioration processes that will affect the long-term rheological reliability of MR materials such as MR elastomer (MRE). This study therefore attempts to investigate the field-dependent rheological characteristics of MRE with corroded carbonyl iron particles (CIPs). The corroded CIPs were treated with hydrochloric acid (HCl) as a way of providing realistic environments in gauging the CIPs reaction towards the ambient conditions. The corroded CIPs along with silicone rubber as a matrix material were used in the fabrication of the MRE samples. To observe the effect of HCl treatment on the CIPs, the morphological observations of MREs with non-corroded and corroded CIPs were investigated via field emission scanning electron microscopy (FESEM), energy-dispersive x-ray spectroscopy (EDX) and x-ray diffractometer (XRD). In addition, the magnetic properties were examined through the vibrating sample magnetometer (VSM), while the field-dependent rheological characteristics such as the storage modulus of MRE with the corroded CIPs were also tested and compared with the non-corroded CIPs. The results showed that the corroded CIPs possessed hydrangea-like structures. In the meantime, it was identified that a sudden reduction of up to 114% of the field-dependent MR effect of MRE with the corroded CIPs was observed as a result of the weakened interfacial bonding between the CIPs and the silicon in the outer layers of the CIPs structure.

Characterization of the Defect Evolution in Thick Heavily Al-Doped 4H-SiC Epilayers

2014 ◽  
Vol 778-780 ◽  
pp. 151-154 ◽  
Author(s):  
Shi Yang Ji ◽  
Kazutoshi Kojima ◽  
Yuuki Ishida ◽  
Hirotaka Yamaguchi ◽  
Shingo Saito ◽  
...  
Keyword(s):  
Misfit Dislocation ◽  
Doping Level ◽  
Growth Stage ◽  
Initial Growth ◽  
Al Doping ◽  
X Ray ◽  
Defect Evolution ◽  
Koh Etching

The defect evolution on 90 μm-thick heavily Al-doped 4H-SiC epilayers with Al doping level higher than 1020 cm-3 was studied by tracing back to initial growth stage to monitor major dislocations and their propagations in each growth stage. Results from X-ray topography and KOH etching demonstrate that all existing dislocations on the surface of 90 μm-thick epilayer can be identified as the defects originating from substrate. In other words, there seems no new dislocation generated after a long-term growth. Nevertheless, a high density of misfit dislocation was found appearing near the substrate/epilayer interface for epilayer with Al doping level of 3.5×1020 cm-3, while misfit dislocation cannot be seen on epilayer with Al doping level of 1.5×1020 cm-3.

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