CCD

This opens perspectives for obtaining phase contrast information in a microfocus tomographic system Recently we have developed a desktop X-ray microtomographic system [4] with a spot size of 8 micrometer (70 KeV) and equipped with a (1024) pixel CCD, lens coupled to a scintillator. The system is now commercially available [5], The setup is sketched in Figure 1 In this work we used the system to demonstrate the feasibility for phase contrast microtomography. 

Compact design. The tube itself has an overall thickness of about 4 cm which limits the total thickness of the imaging unit (optics and CCD) to be less than 15cm. 

Due to the conversion process an absorbed photon give rise to less than one electron generated in the CCD. This phenomenon, also called a "quantum sink" shows that the detector is degrading the S/N ratio of the image. The quality of an image being mainly limited by the quantum noise of the absorbed gamma this effect is very important. 

If the inspection equipment can be run under stable and reproducable conditions due to the QAP the basis for using a camera system for flaw detection is given.The camera system consists of CCD-cameras and a pattern recognition software. Up to four CCD-cameras can be served by one PC. One shot of the part may be copied up to 16 times in the computer and this theoretically enables the crack determination with 16 different parameter sets. 

A CCD camera and the PC are used to process the different null displacement rings whereby the movements can be followed trough in real time, and also very accurately measured. 

A CCD camera is located in the II(t, ) plane. It records the first speekle pattern and proeesses it digitally. After this, the diffuser G is rotated and trtinslated (Figure I). 

As the dimensions of the speckle grain on the detectors is about 1,7 im, 4 times lesser than the pixel dimensions (for D = 350 mm illuminated area = 6,3mm x 2 mm magnification CCD = 0,05), the halo results not very clear. 

Plenary 18. Robin J FI Clark, e-mail address r.i.h.clark ucl.ac.uk (RS). Reports on recent diagnostic probing of art works ranging from illuminated manuscripts, paintings and pottery to papyri and icons. Nondestructive NIR microscopic RS is now realistic using CCD detection. Optimistic about new developments. 

Shaw S L, Salmon E D and Quatrano R S 1995 Digital photography for the light microscope results with a gated, video-rate CCD camera and NIFI-image software BioTechniques 19 946-55... 

Figure Cl.5.9. Vibrationally resolved dispersed fluorescence spectra of two different single molecules of terrylene in polyetliylene. The excitation wavelengtli for each molecule is indicated and tlie spectra are plotted as the difference between excitation and emitted wavenumber. Each molecule s spectmm was recorded on a CCD detector at two different settings of tire spectrograph grating to examine two different regions of tlie emission spectmm. Type 1 and type 2 spectra were tentatively attributed to terrylene molecules in very different local environments, although tlie possibility tliat type 2 spectra arise from a chemical impurity could not be mled out. Furtlier details are given in Tchenio [105-1071.

Figure C 1.5.13. Schematic diagram of an experimental set-up for imaging 3D single-molecule orientations. The excitation laser with either s- or p-polarization is reflected from the polymer/water boundary. Molecular fluorescence is imaged through an aberrating thin water layer, collected with an inverted microscope and imaged onto a CCD array. Aberrated and unaberrated emission patterns are observed for z- and xr-orientated molecules, respectively. Reprinted with pennission from Bartko and Dickson [148]. Copyright 1999 American Chemical Society.

As an example of the applieation of CCD s and SCD s, eonsider the disrotatory elosing of 1,3-butadiene to produee eyelobutene. The OCD given earlier for this proposed reaetion path is reprodueed below. 

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