Performance Optimization for Hard X-ray Microscopy Beamlines Guided by Partially-Coherent Wavefront Propagation Calculations

2010 ◽  
Author(s):  
Oleg Chubar ◽  
Yong S. Chu ◽  
Konstantine Kaznatcheev ◽  
Hanfei Yan ◽  
R. Garrett ◽  
...  
Keyword(s):  
Performance Optimization ◽  
X Ray ◽  
Partially Coherent ◽  
Wavefront Propagation

Partially coherent X-ray wavefront propagation simulations including grazing-incidence focusing optics

2014 ◽  
Vol 21 (5) ◽  
pp. 1110-1121 ◽  
Author(s):  
Niccolo Canestrari ◽  
Oleg Chubar ◽  
Ruben Reininger
Keyword(s):  
Synchrotron Radiation ◽  
National Laboratory ◽  
Grazing Incidence ◽  
Brookhaven National Laboratory ◽  
Wave Optics ◽  
X Rays ◽  
X Ray ◽  
Partially Coherent ◽  
Wavefront Propagation ◽  
Simulation Results

X-ray beamlines in modern synchrotron radiation sources make extensive use of grazing-incidence reflective optics, in particular Kirkpatrick–Baez elliptical mirror systems. These systems can focus the incoming X-rays down to nanometer-scale spot sizes while maintaining relatively large acceptance apertures and high flux in the focused radiation spots. In low-emittance storage rings and in free-electron lasers such systems are used with partially or even nearly fully coherent X-ray beams and often target diffraction-limited resolution. Therefore, their accurate simulation and modeling has to be performed within the framework of wave optics. Here the implementation and benchmarking of a wave-optics method for the simulation of grazing-incidence mirrors based on the local stationary-phase approximation or, in other words, the local propagation of the radiation electric field along geometrical rays, is described. The proposed method is CPU-efficient and fully compatible with the numerical methods of Fourier optics. It has been implemented in theSynchrotron Radiation Workshop(SRW) computer code and extensively tested against the geometrical ray-tracing codeSHADOW. The test simulations have been performed for cases without and with diffraction at mirror apertures, including cases where the grazing-incidence mirrors can be hardly approximated by ideal lenses. Good agreement between theSRWandSHADOWsimulation results is observed in the cases without diffraction. The differences between the simulation results obtained by the two codes in diffraction-dominated cases for illumination with fully or partially coherent radiation are analyzed and interpreted. The application of the new method for the simulation of wavefront propagation through a high-resolution X-ray microspectroscopy beamline at the National Synchrotron Light Source II (Brookhaven National Laboratory, USA) is demonstrated.

Tribological Performance Optimization of Electroless Nickel Coatings Under Lubricated Condition

2018 ◽  
pp. 250-280 ◽  
Author(s):  
Santanu Duari ◽  
Arkadeb Mukhopadhyay ◽  
Tapan Kumar Barman ◽  
Prasanta Sahoo
Keyword(s):  
Performance Optimization ◽  
Friction And Wear ◽  
Electroless Nickel ◽  
Heat Treating ◽  
Wear Depth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Electroless Ni ◽  
Scanning Electron

The present chapter aims to determine optimal tribo-testing condition for minimum coefficient of friction and wear depth of electroless Ni-P, Ni-P-W and Ni-P-Cu coatings under lubrication using grey relational analysis. Electroless Ni-P, Ni-P-W and Ni-P-Cu coatings are deposited on AISI 1040 steel substrates. They are heat treated at suitable temperatures to improve their hardness. Coating characterization is done using scanning electron microscope, energy dispersive X-Ray analysis and X-Ray diffraction techniques. Typical nodulated surface morphology is observed in the scanning electron micrographs of all the three coatings. Phase transformation on heat treating the deposits is captured through the use of X-Ray diffraction technique. Vicker's microhardness of the coatings in their as-deposited and heat treated condition is determined. Ni-P-W coatings are seen to exhibit the highest microhardness. Friction and wear tests under lubricated condition are carried out following Taguchi's experimental design principle. Finally, the predominating wear mechanism of the coatings is discussed.

Note: Nanosecond LED-based source for optical modeling of scintillators illuminated by partially coherent X-ray radiation

2016 ◽  
Vol 87 (12) ◽  
pp. 126104 ◽  
Author(s):  
M. Siano ◽  
B. Paroli ◽  
E. Chiadroni ◽  
M. Ferrario ◽  
M. A. C. Potenza
Keyword(s):  
X Ray ◽  
Optical Modeling ◽  
Partially Coherent

Wear Performance Optimization for Electroless Ni-P Coating

2015 ◽  
Vol 3 (2) ◽  
pp. 1-17 ◽  
Author(s):  
Prasanta Sahoo ◽  
Suman Kalyan Das
Keyword(s):  
Performance Optimization ◽  
System Response ◽  
X Ray Diffraction ◽  
Wear Performance ◽  
X Ray ◽  
Nodular Structure ◽  
Coating Morphology ◽  
Electroless Ni ◽  
Significant Factors

Optimization of the wear performance of electroless Ni-P coating is carried out with the help of Taguchi orthogonal array design. Tribological testing parameters (applied load, sliding speed and duration of testing) are optimized with the help of L27 array in order to get the best wear performance from the coating. Load and time were found to be the most significant factors. Interaction between load and time is also found to hold some amount of significance towards the system response (wear). The characterization of the coating is carried out through scanning electron microscopy, energy dispersive X-ray analysis and X-ray diffraction analysis. The coating morphology is found to resemble a nodular structure and the coating is mainly amorphous in as deposited state. However, post heat treatment at 400ºC for one hour the coating transforms into crystalline structure. The wear mechanism is also studied and found to be a mixture of abrasive and adhesive wear phenomena.

scholarly journals Friction Performance Optimization of Chemically Deposited Ni-P-W Coating Using Taguchi Method

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Supriyo Roy ◽  
Prasanta Sahoo
Keyword(s):  
Taguchi Method ◽  
Process Parameters ◽  
Performance Optimization ◽  
Coated Sample ◽  
Coating Process ◽  
X Ray Diffraction ◽  
Friction Behavior ◽  
X Ray ◽  
Friction Performance ◽  
Roller Configuration

The present study considers the friction behavior of chemically deposited Ni-P-W coatings and optimization of the coating process parameters for minimum friction using Taguchi method. The study is carried out by varying the combination of four coating process parameters, namely, concentration of nickel source, concentration of reducing agent, concentration of tungsten source, and annealing temperature. The friction tests are conducted in a plate-on-roller configuration by keeping the coated sample fixed against a rotating steel roller. The optimum combination of process parameters for minimum friction coefficient is obtained from the analysis of S/N ratio. Furthermore, a statistical analysis of variance reveals that the concentration of nickel source solution has the most significant influence in controlling friction characteristics of Ni-P-W coating. The surface morphology and composition of coatings are also studied with the help of scanning electron microscopy, energy dispersed x-ray analysis, and x-ray diffraction analysis.

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