Energy deposition curve

A further difference between isotope gamma rays and electrons is penetrating ability. As charged particles, electrons have short ranges in matter. Fig. 3 shows energy deposition curves for water irradiated with electrons of various energies. 

The chemical reaction scheme used in the detailed model was used to generate a curve for tc(T). The values of thermal conductivity used in the detailed model were used to generate a function k. Then a series of comparisons were made, in which the detailed model was configured in spherical symmetry with a Gaussian energy deposition. 

Fig. 5. Energy distribution curves at a photon energy of 30 eV for three different conditions (a) after a-Si deposition (b) after H2 exposure at 10 2 Torr for 2 min (c) after 02 exposure at 5 X 10 5 Torr for 7 min at 110°C. The tops of valence tend of SiOx and a-Si H are also extrapolated (dashed lines). The top of SiO, VB shifts from 2.7 e V under the Fermi level to 2.45 eV (AE = 0.25 eV), while the top of a-Si H shifts from 0.6 to 0.35 eV, going from condition (b) to condition (c).

As high-energy electrons pass through an aqueous colloidal suspension of particles, energy is lost via electronic interactions in both the liquid and solid phases in a ratio determined by their relative electron densities and concentration. Thus, as the percentage of solid material increases, so does the fraction of energy deposited in the solid phase. It is common to conduct radiolytic experiments at constant volume (to ensure constant geometry relative to the radiation source). Thus, the dose absorbed in the sample increases with the increase of total density of the sample. This is shown in Fig. 2 as the upper solid curve. 

Figure 11-22. Ignition in H2-O2 mixture stimulated by the fast ionization wave. Solid curve is for H2-O2 without diluents recorded ignition pressures have been adjusted by removing partial pressure of He. Temperatures and pressures are those after passage of the refleeted shoek, but before the fast-ionization-wave energy deposition.

Fig. 5. Photoemission spectra of an ordered Gd(OOOl) film deposited on W(llO) showing the Gd 5d surface state (S) and bulk bands (B). The spectra were taken along the T-A direction of the bulk band structure. Data taken from Dongqi Li et al. (1991a). The solid lines indicate the energy distribution curves taken for bulk gadolinium, adapted from Himpsel and Reihl (1983).

In Figure 19.5 the variation of the Gibbs energy with distance from the electrode surface is given schematically for metal deposition. Curves for different values of the overpotential are shown. 

In section 3.6.3 we mentioned that in growth on a curved face the strain surface free energy os takes the role the lateral surface free energy tr played in the flat surface case, namely that of a barrier to the formation of the first stem. This analogy cannot be made since, in contrast to surface free energy is associated with the deposition of any stem. Therefore and because of its physical origin (the volume strain) it is closely linked with the free energy of fusion. This is... 

The problems of distinguishing H+ produced from H2 by electron impact from the product of dissociative charge transfer reactions between He + and H2 can be studied by determining the kinetic energy distribution in the product H+ (6). The reaction He+ + H2 is exothermic by 6.5 e.v. if the products are atoms or atomic ions. If the reaction is studied with HD substituted for H2, then the maximum kinetic energy that can be deposited in the D + is approximately 2.16 e.v. On the other hand, D + can be produced by electron impact with 5.5 e.v. kinetic energy. If a retarding potential is applied at the repeller in the ion-source of a mass spectrometer, then it is possible to obtain curves related to the kinetic... 

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