Energy spectrum measured

Figure 9.8 A differential energy spectrum measured with an SCA.

An electron energy spectrum measured with a plastic scintillator is shown in Fig. 13.8. It is represented extremely well by the following analytic function, which was developed by Tsoulfanidis et al. ° and is shown in Fig. 13.9. 

The energy spectrum measured with the 3cm x 4 cm large CsI Tl) crystal with APD readout is shown in Figure 5.7. We obtain resolutions of 10% for the 511 keV 7 line and 5% for the 1275 keV 7 line. At 1275 keV, the resolution has equal contributions from electronic noise and other sources, whereas the resolution at 511 keV is dominated by electronic noise. The results obtained for the other crystals and other readout schemes are summarized in Table 5.1. 

Figure 12. Top left Panel Comparison of the Co energy spectrum measured with a l x 1 LaBrs.Ce with those measured with a Nal and with a BaF2 detector (from ref [24]). Top right Panel Comparison of the 6.13 MeV energy spectra from a PuC source measured with a 3 x3 LaBr3. Ce with those measured with a 80% HPGe and with a NaI Tl 3 x3 detector. Bottom Panel Comparison of the monochromatic 15.1 MeV gamma-ray energy spectra emitted in the reaction C(p,p ) C measured with a 3 x3 LaBrssCe with that measured with a NaI Tl 3 x3 detector...

Another solar neutrino electronic experiment directed primarily at a measurement of the flux of 0.861-MeV neutrinos from the reaction Be +e Li - - Vg is known as Borexino it should help to unravel the integrated energy spectrum measurements from the radiochemical detectors. There are also less advanced plans for further detailed study of the solar neutrino spectrum in proposed electronic experiments which seek to explore the neutrinos from the primary fusion reaction p- -p d- -e+ = Ve. 

Figure 20 Typical energy spectrum measured in a He NRA experiment. At low energy (low channels), large numbers of He ions are backscat-tered from the heavier elements in the sample. The nuclear reaction products are detected at higher energy. The H spectrum (inset) may be analyzed to determine the depth distribution of the deutenated polymer.

XPS X-ray photoelectron spectroscopy [131-137] Monoenergetic x-rays eject electrons from various atomic levels the electron energy spectrum is measured Surface composition, oxidation state... 

In this approach one uses narrow-band continuous wave (cw) lasers for continuous spectroscopic detection of reactant and product species with high time and frequency resolution. Figure B2.5.11 shows an experimental scheme using detection lasers with a 1 MFIz bandwidth. Thus, one can measure the energy spectrum of reaction products with very high energy resolution. In practice, today one can achieve an uncertainty-limited resolution given by... 

The electromagnetic spectrum measures the absorption of radiation energy as a function of the frequency of the radiation. The loss spectrum measures the absorption of mechanical energy as a function of the frequency of the stress-strain oscillation. 

An important property of the surface behaviour of oxides which contain transition metal ions having a number of possible valencies can be revealed by X-ray induced photoelectron spectroscopy. The energy spectrum of tlrese electrons give a direct measure of the binding energies of the valence electrons on the metal ions, from which the charge state can be deduced (Gunarsekaran et al., 1994). 

It should be noted that low-loss spectra are basically connected to optical properties of materials. This is because for small scattering angles the energy-differential cross-section dfj/dF, in other words the intensity of the EEL spectrum measured, is directly proportional to Im -l/ (E,q) [2.171]. Here e = ei + iez is the complex dielectric function, E the energy loss, and q the momentum vector. Owing to the comparison to optics (jqj = 0) the above quoted proportionality is fulfilled if the spectrum has been recorded with a reasonably small collection aperture. When Im -l/ is gathered its real part can be determined, by the Kramers-Kronig transformation, and subsequently such optical quantities as refraction index, absorption coefficient, and reflectivity. 

The required distribution of initial populations ntu can be obtained in the following manner (32). Let us consider a system with Ed mi = 20 kcal/ mole and Ed max = 45 kcal/mole. Assuming that kd = 1013 sec-1 and x = 1, we can calculate theoretical desorption rates dnai/dt for Ed = 20, 21, 22,..., 45 kcal/mole as a function of nBOi. With increasing temperature, 25 values of dnjdt are measured at temperatures corresponding to Ed of 20, 21, 22,. . ., 45 kcal/mole. Since the total desorption rate at any moment must be equal to the sum of the individual desorption processes, we obtain 25 linear equations. Their solution permits the computation of the initial populations of the surface sites in the energy spectrum considered, i.e. the function n,oi(Edi). From the form of this function, desorption processes can be determined which exhibit a substantial effect on the experimental desorption curve. 

Figure 5.39. Characterization of the spillover species by photoelectron spectra of the Ols region taken from a 0.02 pm2 spot on the Pt surface (a) The residual O Is spectrum after the cleaning cycles (b) The Ols spectrum measured in 02 atmosphere (pO2=lxI0 6 mbar) (c) The Ols spectrum obtained during electrochemical pumping in vacuum with UWr = 1.1 V. R1 and R2 are the components which are formed by adsorption from the gas phase and by electrochemical pumping. The fitting components of the residual oxygen are shown with dashed lines. Photon energy = 643.2 eV, T 350-400°C.67 Reprinted with permission from Elsevier Science.

Solvent — The transition energy responsible for the main absorption band is dependent on the refractive index of the solvent, the transition energy being lower as the refractive index of the solvent increases. In other words, the values are similar in petroleum ether, hexane, and diethyl ether and much higher in benzene, toluene, and chlorinated solvents. Therefore, for comparison of the UV-Vis spectrum features, the same solvent should be used to obtain all carotenoid data. In addition, because of this solvent effect, special care should be taken when information about a chromophore is taken from a UV-Vis spectrum measured online by a PDA detector during HPLC analysis. 

Figure 4.31. (t0-TOF) versus energy spectrum of 295 nm Cr doped FeSi2 on Si measured at 40° with 230 MeV 129Xe ions (Bohne et al. 2000). 

Figure 2. The binding energy spectrum for valence electrons of ethyne and the corresponding measured and calculated self-consistent-field independent particle orbital momentum densities [5]. 

Figure 9. The measured momentum density of an aluminium film. In the left panel we show the measured momentum density near the Fermi level (error bars), the result of the LMTO calculations (dashed line) and the result of these calculations in combination with Monte Carlo simulations taking into account the effects of multiple scattering (full line). In the central panel we show in a similar way the energy spectrum near zero momentum. In the right panel we again show the energy spectrum, but now the theory is that of an electron gas, taking approximately into account the effects of electron-electron correlation (dashed) and this electron gas theory plus Monte Carlo simulations (solid line).

In the central panel we show a measured energy spectrum near zero momentum compared with the LMTO calculation and the LMTO calculation plus simulation of multiple scattering events. 

The time-of-flight spectrum of the H-atom product from the H20 photodissociation at 157 nm was measured using the HRTOF technique described above. The experimental TOF spectrum is then converted into the total product translational distribution of the photodissociation products. Figure 5 shows the total product translational energy spectrum of H20 photodissociation at 157.6 nm in the molecular beam condition (with rotational temperature 10 K or less). Five vibrational features have been observed in each of this spectrum, which can be easily assigned to the vibrationally excited OH (v = 0 to 4) products from the photodissociation of H20 at 157.6 nm. In the experiment under the molecular beam condition, rotational structures with larger N quantum numbers are partially resolved. By integrating the whole area of each vibrational manifold, the OH vibrational state distribution from the H2O sample at 10 K can be obtained. In... 

In order to see the effect of the rotational excitation of the parent H2O molecules on the OH vibrational state distribution, the experimental TOF spectrum of the H atom from photodissociation of a room temperature vapor H2O sample has also been measured with longer flight distance y 78 cm). By integrating each individual peak in the translational energy spectrum, the OH product vibrational distribution from H2O photodissociation at room temperature can be obtained. 

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