Electron degradation spectra

In order to estimate the contribution of secondary electrons, degradation spectrum, or in other words slowing down spectrum, is used. Degradation spectrum is defined as the length of the secondary electron trajectory, where the electron with the initial energy dissipates its energy between E and E+dE. 

Figure 6 Contribution of the electron degradation spectrum to ionization and excitation in gaseous nitrogen calculated by binary-encounter collision theory with irradiation of 100-keV electron. (From Ref 15.)...

An early theory of the IT value was proffered by Spencer and Fano [44], based on the degradation spectrum. Another method, the Fowler equation, was employed by Inokuti [47] for electron irradiation, based on the approximation that there is only one ionization potential and that the ionization efficiency is unity. These restrictions can be relaxed. The main result of Inokuti s analysis may be given as follows. 

The physical stage of a (3- or y-radiolysis of a sufficiently diluted medium is described in this theory (see Table I) as the interaction of the degradation spectrum of electrons with the ensemble of isolated molecules of the gas. The probabilities of individual inelastic collisions are characterized by their cross sections and the solution of the problem is,... 

No corresponding detailed theory of the action of slow electrons exists. Their fraction in the degradation spectrum is nevertheless so substantial that their contribution to the radiolysis must be considered as very important. The reason is that they are formed abundantly as secondary electrons from optical ionizations and contribute considerably... 

In this relation, is the specific heat related to vibrational degrees of freedom of CO2 molecules the factor in parentheses is determined by the degradation spectrum Z(s) of 5-electrons in tracks (Nikerov Sholin, 1978, 1985) and nttmerically is about several electron volts (Belousov et al., 1979). The plasma effect in CO2 radiolysis is mostly related to stimulation of the reaction... 

As noted above, there are several ways of creating an inner shell vacancy which may de-excite via the emission of a characteristic X-ray. XRF uses a primary beam of X-rays, but suffers from the fact that the characteristic X-ray spectrum recorded from a solid sample contains a scattered version of the primary spectrum, increasing the background signal and therefore degrading analytical sensitivity. The use of an electron beam to create inner shell... 

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