Amplitude reduction factor

For a given shell, the maximum amplitude is given by the product of the number (N) of the j type of scatterer times its respective backscattering amplitude, F (fc). This maximum amplitude is then reduced by a series of amplitude reduction factors which are considered below. 

Figure 5 Amplitude Reduction Factor and Self-Bias Potential Versus Power Density at 35mTorr...

Table III is a summary of results obtained for 02/RIE of PMMA at 0.125 Watts/cm2 and 0.75 Watts/cm2 and 5mTorr and 35mTorr. The amplitude reduction factor is approximately equal to unity (sharp/smooth surface) at 5mTorr for both power levels while values less than unity occur at 35mTorr, indicating greater roughening.

Table III. Amplitude Reduction Factor and Oxygen RIE Rate of PMMA...

Oscillation amplitude reduction factor (1 ), f (a -b)/(a - b + 2s), where a and b are maximum and minimum reflected light intensities during dissolution and s is the offset (Figure 6). 

The amplitude reduction factor Sq takes accoimt of the fact that some of the electrons that have been excited cannot contribute to the EXAFS due to electronic processes taking place within the absorbing atom itself (e.g., so-called shake-up and shake-down processes [12]) thus, in principle, Sq depends only on atom type i. 

In addition to the terms defined above, there is an amplitude reduction factor which allows for the multi-electron processes at the central atom such as shake up and shake off. Difficulties arise from the estimation of the back-scattering factors and phase shifts. These are sometimes considered to be empirical parameters... 

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