Admittance, definition

In our opinion, the interesting photoresponses described by Dvorak et al. were incorrectly interpreted by the spurious definition of the photoinduced charge transfer impedance [157]. Formally, the impedance under illumination is determined by the AC admittance under constant illumination associated with a sinusoidal potential perturbation, i.e., under short-circuit conditions. From a simple phenomenological model, the dynamics of photoinduced charge transfer affect the charge distribution across the interface, thus according to the frequency of potential perturbation, the time constants associated with the various rate constants can be obtained [156,159-163]. It can be concluded from the magnitude of the photoeffects observed in the systems studied by Dvorak et al., that the impedance of the system is mostly determined by the time constant. 

For definition of the different characteristic resonance frequencies, the locus of impedance Z = R+jX (a) and admittance Y = l/Z = G + jB (h) of a bare quartz crystal are shown in Fig. 12 (for better distinction Rs has been set to 160 12 here, a typical value for single-side liquid load). The definilions are summarized in Table 2 [34]. 

The circuit shown in Eigure 2.2.2a is just that originally proposed by Cole and Cole [1941] for dielectric systems. It yields capacitances Co in the ft) 0 limit and C in the ft) —> °o limit. When one uses the Eq. (18) definition of the CPE admittance, it leads to the following expression for e. 

In some parts of the controlled area, compliance with relevant limits can be achieved only by limiting the time spent there or by using special protective equipment. The definition of different zones within a controlled area, on the basis of dose rates or levels of non-fixed contamination, should be considered. Some zones will necessitate setting conditions for restricted and special entries. Local rules or radiation work permits may be used for administrative control of admittance into these zones. 

Propagation constant F and characteristic impedance Zq of a conductor are frequency dependent as they are functions of the impedance of the conductor, as explained in Section 1.2. It should be noted that a and p in Section 1.3.4.1 (see Figure 1.10) are not frequency dependent (in the sense discussed in this section). The frequency dependence of the attenuation constant a(co) and phase constant P(co) in Section 1.3.4.1 comes from the definition of impedance Z and admittance Fof a conductor ... 

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