Detector types imaging

As in the case of STEM, the main benefit arising from the use of the scanning mode is that the incident electron probe can be stopped or controlled in its motion and a variety of detector types and configurations can be used to obtain particular signals, giving information beyond that obtained in the normal Imaging modes. 

Great promise also lies in the further development of solid-state pixel detectors for X-ray imaging. Small versions of this detector type are now being used in several industrial and medical imaging applications. However, the technology is relatively immature and requires significant improvement to make it suitable for use in advanced research applications. Another important need is the... 

Figure 14.1 Detector types. Five different detector designs are shown in their fundamental units. (This is an adaptation of an image in ref. 4.)...

Kruse and Skatrud (1997) Uncooled Infrared Imaging Arrays and Systems by Volume Editors P. W. Kruse and D. D. Skatrud, Academic Press, San Diego, CA, Chestnut Hill, MA. This is a comprehensive review, including a chapter on the history of thermal detectors, and chapters on each of the significant thermal detector types. 

There are three principal types of position-sensitive X-ray detectors of use for crystallography—the vidicon, solid-state devices (largely charge-coupled devices), and proportional counters. Vidicons are area detectors which use image intensifier techniques to produce TV-type images. They are not count rate limited and are therefore well suited for use with high-flux sources... 

There are two principal neutron imaging techniques in NR - direct and transfer (indirect). In the former the neutron converter and the detector are simultaneously exposed in the neutron beam while in the transfer technique only the converter screen is exposed and activated by the neutrons, and transfered out of the neutron beam to subsequently expose the detector. Various types of IP can be used in both of neutron imaging techniques. 

Detectors. Two general types of detectors are used in x-ray medical imaging scintillation and gas ionisation. Scintillation detectors are used for both conventional projection and computerized tomographic imaging. Ionization detectors have been used only in CT appHcations. All detectors used in detection of x-ray radiation must be linear and have a maximum efficiency at the wavelength of the x-ray photon to be detected. 

Miscellaneous. Chloroplatinic acid is used in the production of automobile catalysts. Platino-type prints based on reduction of Pt(II) to Pt(0) by a photosensitive reducing agent such as iron(III) oxalate are used in art photography (261,262). Infrared imaging devices based on a platinum siLicide detector have been developed (263). 

The Mattauch-Herzoggeometry (Fig. 3.20) enables detection of several masses simultaneously and is, therefore, ideal for scanning instruments [3.49]. Up to five detectors are adjusted mechanically to locations in the detection plane, and thus to masses of interest. Because of this it is possible to detect, e. g., all isotopes of one element simultaneously in a certain mass range. Also fast, sensitive, and precise measurements of the distributions of different isotopes are feasible. This enables calculation of isotope ratios of small particles visible in the image. The only commercial instrument of this type (Cameca Nanosims 50) uses an ion gun of coaxial optical design, and secondary ion extraction the lateral resolution is 50 nm. 

Collecting optics, radiation detectors and some form of indicator are the basic elements of an industrial infrared instrument. The optical system collects radiant energy and focuses it upon a detector, which converts it into an electrical signal. The instrument s electronics amplifies the output signal and process it into a form which can be displayed. There are three general types of instruments that can be used for predictive maintenance infrared thermometers or spot radiometers line scanners and imaging systems. 

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