scholarly journals Additive fabrication of nanostructures with focused soft X-rays

RSC Advances ◽  
2016 ◽  
Vol 6 (100) ◽  
pp. 98344-98349 ◽  
Author(s):  
Andreas Späth ◽  
Fan Tu ◽  
Florian Vollnhals ◽  
Martin Drost ◽  
Sandra Krick Calderón ◽  
...  

In a novel approach a high-resolution soft X-ray microscope has been applied to generate metallic nanostructures by X-ray beam induced decomposition of precursor molecules supplied from the gas phase.

Author(s):  
Tyler Pendleton ◽  
Luke Hunter ◽  
S. H. Lau

Abstract Conventional microCTs or 3D x-ray upgrades from existing 2D x-ray systems have two major drawbacks when they are used for failure analysis of advanced packages: Insufficient resolution to image small (1 to 5 microns) materials and the lack of imaging contrast to visualize cracks, whiskers, and defects within low Z materials. This paper discusses some of the failure analysis (FA) case studies of wireless modules using a high resolution micro x-ray CT (XCT). These examples show the value of high resolution XCT as a novel approach to some common package level defects, including some interesting case examples, where failure mechanisms have been uncovered which could not have been done, using conventional means. The non-invasive FA technique for RF modules technique has been shown to dramatically improve the FA engineers' chances of identifying defects over conventional 2D x-rays and avoid the need for physical and tedious cross sectioning of these devices.


1998 ◽  
Vol 5 (3) ◽  
pp. 515-517 ◽  
Author(s):  
M. Frank ◽  
C. A. Mears ◽  
S. E. Labov ◽  
L. J. Hiller ◽  
J. B. le Grand ◽  
...  

Experimental results are presented obtained with a cryogenically cooled high-resolution X-ray spectrometer based on a 141 × 141 µm Nb-Al-Al2O3-Al-Nb superconducting tunnel junction (STJ) detector in an SR-XRF demonstration experiment. STJ detectors can operate at count rates approaching those of semiconductor detectors while still providing a significantly better energy resolution for soft X-rays. By measuring fluorescence X-rays from samples containing transition metals and low-Z elements, an FWHM energy resolution of 6–15 eV for X-rays in the energy range 180–1100 eV has been obtained. The results show that, in the near future, STJ detectors may prove very useful in XRF and microanalysis applications.


2007 ◽  
Vol 130 ◽  
pp. 7-14 ◽  
Author(s):  
Andrew N. Fitch

The highly-collimated, intense X-rays produced by a synchrotron radiation source can be harnessed to build high-resolution powder diffraction instruments with a wide variety of applications. The general advantages of using synchrotron radiation for powder diffraction are discussed and illustrated with reference to the structural characterisation of crystalline materials, atomic PDF analysis, in-situ and high-throughput studies where the structure is evolving between successive scans, and the measurement of residual strain in engineering components.


1991 ◽  
Vol 01 (03) ◽  
pp. 251-258 ◽  
Author(s):  
M. TERASAWA

K, L, and M X-rays in the wavelengths between 6Å and 130Å generated by the bombardment of 200 keV protons and other heavy ions were measured by means of a wavelength dispersive Bragg’s spectrometer. The X-ray peak intensity was fairly high in general, while the background was very low. The technique was favorably applied to a practical analysis of several light elements (Be, B, C, N, O, and F). Use of moderate-energy heavy ions considering the wavelength selectivity in X-ray generation was effective for the element analysis. The high-resolution spectrometry in the analytical application of ion-induced X-ray generation was found to be useful for the study of fine electronic structure, e.g. satellite and hypersatellite X-ray study, and of the chemical state of materials.


Author(s):  
Marta M. Civitani ◽  
Stefano Basso ◽  
Salvatore Incorvaia ◽  
Luigi Lessio ◽  
Giovanni Pareschi ◽  
...  
Keyword(s):  
X Ray ◽  

2016 ◽  
Vol 23 (6) ◽  
pp. 1462-1473 ◽  
Author(s):  
Sebastian Cartier ◽  
Matias Kagias ◽  
Anna Bergamaschi ◽  
Zhentian Wang ◽  
Roberto Dinapoli ◽  
...  

MÖNCH is a 25 µm-pitch charge-integrating detector aimed at exploring the limits of current hybrid silicon detector technology. The small pixel size makes it ideal for high-resolution imaging. With an electronic noise of about 110 eV r.m.s., it opens new perspectives for many synchrotron applications where currently the detector is the limiting factor,e.g.inelastic X-ray scattering, Laue diffraction and soft X-ray or high-resolution color imaging. Due to the small pixel pitch, the charge cloud generated by absorbed X-rays is shared between neighboring pixels for most of the photons. Therefore, at low photon fluxes, interpolation algorithms can be applied to determine the absorption position of each photon with a resolution of the order of 1 µm. In this work, the characterization results of one of the MÖNCH prototypes are presented under low-flux conditions. A custom interpolation algorithm is described and applied to the data to obtain high-resolution images. Images obtained in grating interferometry experiments without the use of the absorption grating G2are shown and discussed. Perspectives for the future developments of the MÖNCH detector are also presented.


2021 ◽  
Author(s):  
Md Inzamam Ul Haque ◽  
Abhishek K Dubey ◽  
Jacob D Hinkle

Deep learning models have received much attention lately for their ability to achieve expert-level performance on the accurate automated analysis of chest X-rays. Although publicly available chest X-ray datasets include high resolution images, most models are trained on reduced size images due to limitations on GPU memory and training time. As compute capability continues to advance, it will become feasible to train large convolutional neural networks on high-resolution images. This study is based on the publicly available MIMIC-CXR-JPG dataset, comprising 377,110 high resolution chest X-ray images, and provided with 14 labels to the corresponding free-text radiology reports. We find, interestingly, that tasks that require a large receptive field are better suited to downscaled input images, and we verify this qualitatively by inspecting effective receptive fields and class activation maps of trained models. Finally, we show that stacking an ensemble across resolutions outperforms each individual learner at all input resolutions while providing interpretable scale weights, suggesting that multi-scale features are crucially important to information extraction from high-resolution chest X-rays.


2019 ◽  
Vol 490 (4) ◽  
pp. 5596-5614 ◽  
Author(s):  
Lisa Wölfer ◽  
Giovanni Picogna ◽  
Barbara Ercolano ◽  
Ewine F van Dishoeck

ABSTRACT The so-called transition discs provide an important tool to probe various mechanisms that might influence the evolution of protoplanetary discs and therefore the formation of planetary systems. One of these mechanisms is photoevaporation due to energetic radiation from the central star, which can in principal explain the occurrence of discs with inner cavities like transition discs. Current models, however, fail to reproduce a subset of the observed transition discs, namely objects with large measured cavities and vigorous accretion. For these objects the presence of (multiple) giant planets is often invoked to explain the observations. In our work, we explore the possibility of X-ray photoevaporation operating in discs with different gas-phase depletion of carbon and show that the influence of photoevaporation can be extended in such low-metallicity discs. As carbon is one of the main contributors to the X-ray opacity, its depletion leads to larger penetration depths of X-rays in the disc and results in higher gas temperatures and stronger photoevaporative winds. We present radiation-hydrodynamical models of discs irradiated by internal X-ray + EUV radiation assuming carbon gas-phase depletions by factors of three, 10, and 100 and derive realistic mass-loss rates and profiles. Our analysis yields robust temperature prescriptions as well as photoevaporative mass-loss rates and profiles which may be able to explain a larger fraction of the observed diversity of transition discs.


1984 ◽  
Vol 17 (5) ◽  
pp. 337-343 ◽  
Author(s):  
O. Yoda

A high-resolution small-angle X-ray scattering camera has been built, which has the following features. (i) The point collimation optics employed allows the scattering cross section of the sample to be directly measured without corrections for desmearing. (ii) A small-angle resolution better than 0.5 mrad is achieved with a camera length of 1.6 m. (iii) A high photon flux of 0.9 photons μs−1 is obtained on the sample with the rotating-anode X-ray generator operated at 40 kV–30 mA. (iv) Incident X-rays are monochromated by a bent quartz crystal, which makes the determination of the incident X-ray intensity simple and unambiguous. (v) By rotation of the position-sensitive proportional counter around the direct beam, anisotropic scattering patterns can be observed without adjusting the sample. Details of the design and performance are presented with some applications.


1981 ◽  
Vol 34 (2) ◽  
pp. 155 ◽  
Author(s):  
HJ Hay ◽  
LF Pender ◽  
PB Treacy

With a high-resolution Si(Li) X-ray detector, characteristic K X rays have been detected with targets of Cr, Fe, Cu, Ge and Se ombarded by 100 MeV Cu ions, equilibrated by passing through carbon. Cross sections for X-ray production, target-to-projectile vacancy-sharing ratios and K, to K, ratios were measured and compared with predictions of molecular-coupling theories. The results show little greement with existing models based on rotational coupling in molecular-orbital states.


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