Spectrograph single

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.

Spectrographically standardised substances 830 Spectrophotometer cells for, 664 data presentation, 665 double-beam, 667 layout of instruments, 666, 667 operation of, 672 radiation sources for, 664 single-beam, 666... 

It is obvious that a record of the kind in Figure 7-1 can yield valuable information about an unknown mineral in the minimum time at little cost. The x-ray emission spectrograph may well become the most valuable single tool for the qualitative analysis of minerals. Its advantages are obvious enough to make further discussion supererogatory. 

Although it is possible to provide electrical equipment that will make it possible to operate a spectrograph from almost any electric power source, it is simpler in the United States to use the single-phase, 3-wire, 60-cycle, 220-110-volt service that is standard for the American home. 

A good diffractometer-spectrograph must function satisfactorily in each role, and it must be built so that the changeover from one to the other is easy, quick, and sure. Unless this is true, two instruments will often be needed where one might have sufficed. The diffractometer should handle either powder samples or single crystals. 

Because it is desirable to see whether the calculated results in Table 10-3 are realistic, measurements were accordingly made in the authors laboratory on a General Electric XRD-5 D/S spectrograph (9.5) under conditions that minimized all errors except the counting error. Instead of comparing standard and unknown, as in Table 10-1, analytical lines for two elements, cobalt and iron, were compared because this could be done on a single sample. 

Two manipulative errors that occur generally in laboratory x-ray emission spectrographs qualify for special attention. The first is the error in setting the goniometer—the reset error. The second is that traceable to the placing of samples in the spectrograph, either to the repeated placement of a single sample, or to the replacement of one... 

This chapter will concentrate on the very high quality detectors that are needed in scientific imagers and spectrographs, and other applications that require high sensitivity, such as acquisition and guiding, adaptive optics and interferometry. We limit our discussion to focal plane arrays - large two-dimensional arrays of pixels - as opposed to single pixel detectors (e.g., avalanche photodiodes). 

The implementation of notch filters makes the application of compact single-stage spectrographs, as used for chemical sensors, possible in the first place. Additionally, it permits to detect Raman lines much closer to the Rayleigh wavelength than previously possible. 

It is interesting to observe that a typical large Littrow Spectrograph having a single Quartz prism covers a wavelength range from 2000 to 80000 A. 

Using a high-resolution spectrograph and a Fabry-Perrot interferometer, Gunther eta/. 727) resolved a number of equidistant components with a mean separation of 0.04 cm" in the stimulated Raman spectrum of CSj, which can be attributed to resonant modes in single medium-scale filaments of self-trapped radiation within the liquid. 

Whenever all the possible components present in significant amount in any given fraction of petroleum are known, and when reliable values are available for the simple physical properties of pure samples of the possible components, the identification of a substance separated from the given fraction becomes a relatively simple matter. In such case, the procedure would be to establish the fact that the material separated is substantially a single substance, measure its simple physical properties, and match these physical properties with those of one of the possible components. In many cases, spectrographic identification can be made more readily than identification by measurement of the simple physical properties. 

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