Sources efficiency

The point source efficiency at each distance from the center point (as shown in Fig. 5) vs energy is shown in Fig. 7. The dependence on energy is typical for p-type detectors. Note... 

The performance of the technique might be increased by an optimization of the ion source efficiency and higher optical excitation probability affecting both the overall efficiency and the selectivity. These improvements should enable us to lower the detection limit for Sr and extend the measurements to Sr (see also Bolshov et al., 1981 Letkhov, 1987). 

After the separation and purification stages, isotopic abundances are measured in most cases by mass spectrometry. Exceptions include shortlived radioactive isotopes, where decay rates are measured by fission track dating that measures the abundance of 238U by induced fission. Ionisation is carried out using a thermal method for a solid source or electron bombardment for a gas source. Efficiency of ionisation determines the amount of sample required for analysis, and efficiency may range from almost 100%... 

In contrast, the influence on polymer density becomes almost nonexistent when the support is alumina or an aluminophosphate—in part because fewer a-olefins are produced, and also because these catalysts do not incorporate comonomers (from any source) efficiently. The data of Table 66 provide a comparison of the performance of Cr/silica with the performance of three Cr/aluminophosphate catalysts in which the P/Al ratio was varied. Because all four polymers were made under the same conditions, it is clear that Cr/silica produced polymer with a much lower density (more in situ branching) than any of the Cr/aluminophosphates. Cr/alumina produced the polymer with the next lowest density. 

The purpose of light delivery devices is to transport the light from the source efficiently to the target tissue, whether this be surface, intraluminal or interstitial. 

The selection of radiation sources including output power, source efficiency, spectral distribution, shape, dimensions, maintenance and operating requirements (wanu up and cooling periods)... 

Fallon SJ, Guilderson TP, Brown TA. CAMS/LLNL ion source efficiency revisited. Nucl Instrum Methods Phys Sect B Beam Interact Mater Atoms 2007 259 (1) 106-110. 

Rhodium-catalysed transfer hydrogenation of cyclic sulfamidate imine 4,5-diphenyl-5H-l,2,3-oxathiazole-2,2-dioxide using HCOOH/N(C2H5)3 mixture as a hydrogen source efficiently produces 4,5-diphenyl-l,2,3-oxathiazoUdine-2,2-dioxide with 98% ee as almost single diastereomer (Scheme 5.16) [57]. 

Only part of the total source power is transmitted to bound rays the rest excites leaky rays, which is discussed in Chapter 8. If we denote the amount of source power transmitted to all bound rays by Pj, then the source (Efficiency S is defined by... 

This profile is given by the q = 2 clad parabolic-profile in Table 2-1, page 40. The total bound-ray power and source efficiency are obtained in an analogous manner to the step-profile expressions above. Hence... 

Source efficiency is a minimum when a -> 0, corresponding to a uniform source, and doubles as a -> oo, when only on-axis illumination occurs. However, although efficiency increases with increasing nonuniformity, bound-ray power decreases and is negligible as a-> oo. 

Outside of the circular region only leaky rays are excited, as discussed in Chapter 8. When 00 = 0 and the beam is on axis, bound rays are excited over the whole core and propagate parallel to the fiber axis. If the beam carries uniform power P per unit cross-sectional area, then the total bound-ray power and source efficiency of Eq. (4-11) are given by... 

In the last five sections we have shown how a lens, on the one hand can increase source efficiency for collimated beam illumination of a fiber, while, on the other hand, it is ineffective at increasing the efficiency of the diffuse source. If we couple these facts with the description of the diffuse source as a superposition of collimated beams, it is evident that the efficiency of a partially diffuse source can be increased by a lens. The situation is illustrated in Fig. 4—8. We assume the step-profile fiber is weakly guiding so that 9 1, and the focal length satisfies... 

There are several ways to characterize the NICMOS performance. The following sections give information on several observing modes and performance characteristics. In the following calculations we assume an efficiency factor of 0.31 times the filter transmission, hi the calculation of the point source efficiency we will use an average filter efficiency of 0.77 for a total... 

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