Resolution spectral

Spectral resolution is a measure of the capability of a spectrophotometer to distinguish between two closely adjacent wavelengths. The wavelengths are considered to be resolved if the trough between the two peaks in the spectrum 

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XPS is also often perfonned employing syncln-otron radiation as the excitation source [59]. This technique is sometimes called soft x-ray photoelectron spectroscopy (SXPS) to distinguish it from laboratory XPS. The use of syncluotron radiation has two major advantages (1) a much higher spectral resolution can be achieved and (2) the photon energy of the excitation can be adjusted which, in turn, allows for a particular electron kinetic energy to be selected. 

Light sources can either be broadband, such as a Globar, a Nemst glower, an incandescent wire or mercury arc lamp or they can be tunable, such as a laser or optical parametric oscillator (OPO). In the fomier case, a monocln-omator is needed to achieve spectral resolution. In the case of a tunable light source, the spectral resolution is detemiined by the linewidth of the source itself In either case, the spectral coverage of the light source imposes limits on the vibrational frequencies that can be measured. Of course, limitations on the dispersing element and detector also affect the overall spectral response of the spectrometer. 

The spectral resolution of the Fourier transfonned data is given by the wavelength corresponding to the maximum optical delay. We have and therefore AD = 1/5,. Therefore, if 0.1 cm spectral... 

Even for a single radical tire spectral resolution can be enlianced for disordered solid samples if the inliomogeneous linewidth is dominated by iimesolved hyperfme interactions. Whereas the hyperfme line broadening is not field dependent, tire anisotropic g-matrix contribution scales linearly with the external field. Thus, if the magnetic field is large enough, i.e. when the condition... 

Transition Widths and Strengths. The widths and strengths of spectroscopic transitions determine the information that can be extracted from a spectmm, and are functions of the molecular parameters summarized in Table 2. Detectivity is deterrnined by spectral resolution and transition strength. Resolution, the abiUty to distinguish transitions of nearly equal wavelength, depends on both the widths of the spectral features and characteristics of the instmmentation. Unperturbed transitions have natural, Av widths owing to the intrinsic lifetimes of the states involved. The full width at... 

Spectral resolution. Consider a Mn Ka photon, which has a namral peak width (the foil width at half maximum, or FWHM) of approximately 1... 

Secondly, spectral resolution can be significantly higher for UPS or synchrotron data, compared to XPS. This is simply a consequence of UPS (synchrotron) sources... 

There are two major drawbacks to ISS concerning quantitative analysis. First, it has very low spectral resolution. Thus it is very difficult either to identify or resolve many common adjacent elements, such as Al/SI, K/Ca, and Cu/Zn. If the elements of interest are sufficiendy high in mass, this can be partially controlled by using a probe gas with a higher atomic mass, such as Ne or Ar. Second, ISS has an inherendy high spectral background which often makes it difficult to determine... 

Optimum resolution, i. e. low full width at half-maximum (FWHM), is a trade-off between high count rate, i. e. low dead-time, and good spectral resolution. 

In the infrared spectral range in general Fourier transform (FT) interferometers are used. In comparison with dispersive spectrometers FTIR enables higher optical throughput and the multiplex advantage at equivalent high spectral resolution. In... 

In conclusion RAIRS, which affords high spectral resolution, is a very versatile nondestructive optical technique which does not depend on a vacuum environment. Vibrational spectra also serve as characteristic fingerprints for adsorbate molecules, adsorption configurations, and structures on metallic and dielectric substrates. Extension to include dielectric substrates opened new fields of application in polymer and biochemical research. 

For large molecules, at least, Raman spectra contain numerous bands which cannot always completely he assigned to particular vibrational modes. The large number of bands can, however, when measured with appropriate spectral resolution, enable unambiguous identification of substances by comparing the spectral pattern ("fingerprint") with those of reference spectra, if they are available. 

The optical train employed for photometric determinations of fluorescence depends on the problem involved. A spectral resolution of the emitted fluorescence is not necessary for quantitative determinations. The optical train sketched in Figure 22B can, therefore, be employed. If the fluorescence spectrum is to be determined the fluorescent light has to be analyzed into its component parts before reaching the detector (Fig. 28). A mercury or xenon lamp is used for excitation in such cases. 

FT instruments of higher magnetic field strengths, providing greater spectral resolution and sensitivity... 

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