A Fiber Optics Camera for Recording Sequences of X-Ray Pictures

1962 ◽  
Vol 71 (8) ◽  
pp. 585-590 ◽  
Author(s):  
J. S. Courtney-Pratt ◽  
J. W. McLaughlin ◽  
E. C. Schramm ◽  
Heinz Alberti
Keyword(s):  
Author(s):  
James F. Mancuso ◽  
William B. Maxwell ◽  
Russell E. Camp ◽  
Mark H. Ellisman

The imaging requirements for 1000 line CCD camera systems include resolution, sensitivity, and field of view. In electronic camera systems these characteristics are determined primarily by the performance of the electro-optic interface. This component converts the electron image into a light image which is ultimately received by a camera sensor.Light production in the interface occurs when high energy electrons strike a phosphor or scintillator. Resolution is limited by electron scattering and absorption. For a constant resolution, more energy deposition occurs in denser phosphors (Figure 1). In this respect, high density x-ray phosphors such as Gd2O2S are better than ZnS based cathode ray tube phosphors. Scintillating fiber optics can be used instead of a discrete phosphor layer. The resolution of scintillating fiber optics that are used in x-ray imaging exceed 20 1p/mm and can be made very large. An example of a digital TEM image using a scintillating fiber optic plate is shown in Figure 2.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Elena Basso ◽  
Federica Pozzi ◽  
Jessica Keister ◽  
Elizabeth Cronin

AbstractIn the late 19th and early 20th centuries, original photographs were sent to publishers so that they could be reproduced in print. The photographs often needed to be reworked with overpainting and masking, and such modifications were especially necessary for low-contrast photographs to be reproduced as a letterpress halftone. As altered objects, many of these marked-up photographs were simply discarded after use. An album at The New York Public Library, however, contains 157 such photographs, all relating to the Jackson–Harmsworth expedition to Franz Josef Land, from 1894 to 1897. Received as gifts from publishers, the photographs are heavily retouched with overpainting and masking, as well as drawn and collaged elements. The intense level of overpainting on many of the photographs, but not on others, raised questions about their production and alteration. Jackson’s accounts attested to his practice of developing and printing photographs on site, testing different materials and techniques—including platino-bromide and silver-gelatin papers—to overcome the harsh environmental conditions. In this context, sixteen photographs from the album were analyzed through a combination of non-invasive and micro-invasive techniques, including X-ray fluorescence (XRF) spectroscopy, fiber optics reflectance spectroscopy (FORS), Raman and Fourier-transform infrared (FTIR) spectroscopies, and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDS). This analytical campaign aimed to evaluate the possible residual presence of silver halides in any of the preliminary and improved photographs. The detection of these compounds would be one of several factors supporting a hypothesis that some of the photographs in the album were indeed printed on site, in the Arctic, and, as a result, may have been impacted by the extreme environment. Additional goals of the study included the evaluation of the extent of retouching, providing a full characterization of the pigments and dyes used in overpainted prints, and comparing the results with contemporaneous photographic publications that indicate which coloring materials were available at the time. Further analyses shed light on the organic components present in the binders and photographic emulsions. This research has increased our knowledge of photographic processes undertaken in a hostile environment such as the Arctic, and shed light on the technical aspects of photographically illustrating books during the late 19th and early 20th centuries.


1966 ◽  
Vol 9 (5) ◽  
pp. 194-195 ◽  
Author(s):  
L. Marton
Keyword(s):  

2005 ◽  
Vol 44 (29) ◽  
pp. 6193 ◽  
Author(s):  
Yuji Matsuura ◽  
Tadaaki Oyama ◽  
Mitsunobu Miyagi

2021 ◽  
Vol 2 (2) ◽  
pp. 325-340
Author(s):  
Amani-Christiana Saint ◽  
Vasiliki Dritsa ◽  
Maria Koui

A multi-analytical non-destructive testing (NDT) methodology was applied to copper-based artifacts originated from various archaeological sites of Greece. X-ray fluorescence (XRF), fiber optics diffuse reflectance spectroscopy (FORS) and scanning electron microscopy coupled with an energy dispersive X-ray detector (ESEM-EDX) were used for the characterization of the alloys and the corrosion products. The key elements of the artifacts belonging to the Early Bronze Age (2700–2300 BC) were copper and arsenic, while tin bronze was used for the fabrication of the Late Bronze Age (1600–1100 BC) artifacts. The effectiveness of XRF for the determination of the bulk composition was confirmed by comparative study with the previously applied atomic absorption spectroscopy (AAS) and inductively coupled plasma–atomic emission spectrometry (ICP-AES) destructive techniques. Significant differences between the artifacts were revealed through the spectral measurement of their surface corrosion products color by FORS. ESEM-EDX provided information on the microstructure, the elemental composition of the corrosion layers and bulk, as well as the distribution of the corrosion products on the surface. Conclusively, the combined NDT methodology could be regarded as a valuable and appropriate tool for the elemental composition of the bulk alloy, thus leading to the classification of their historical period and the corrosion products, contributing significantly to their conservation–restoration.


1993 ◽  
Author(s):  
Daniel R. Parsignault ◽  
Allen S. Krieger
Keyword(s):  
X Ray ◽  

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Edgar Casanova-González ◽  
Miguel Ángel Maynez-Rojas ◽  
Alejandro Mitrani ◽  
Isaac Rangel-Chávez ◽  
María Angélica García-Bucio ◽  
...  

Abstract Almost three hundred Spanish colonial missions—or their remains—are scattered over the vast state of Chihuahua in northern Mexico. A few of them still display painted decorations on the wood ceilings and walls. The decorated areas vary greatly, from the whole ceiling of the main aisle to just a few square meters in a lateral chapel, and so does the conservation state of the paintings. In this context, the information regarding the paintings’ composition plays a key role in the restoration and conservation processes. For the gathering of such information, we propose a combined methodology for a fast, non-destructive and non-invasive characterization of such paintings with a minimum of techniques. This methodology includes false color infrared imaging as a first approach to determine the composition of large areas of the paintings and the homogeneity of the materials used in the painted areas, followed by small area analysis by X-ray fluorescence and fiber-optics reflectance spectroscopy. This methodology was applied to characterize the elemental and molecular composition of the decorations for four missions in Chihuahua in a fast and specific manner, revealing the use of a mix of mineral and organic materials including indigo and cochineal, and detecting differences between the missions. The methodology presented here can be easily applied for the study of a wider number of missions in Chihuahua and other regions to provide outstanding information of materials, pictorial techniques and deterioration conditions.


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