Automatic Analysis Method for the Threshold and Power Exponent of Spectra Interpreted by the Power Law

Abstract

Automatic estimation methods (1/n-Power Plot and Shift-Log-Log Plot methods) are proposed to estimate the power exponent of a spectrum following a power law and the threshold at which the power begins to increase. The 1/n-Power Plot method is used when there is prior information on the power exponent and the inverse of the power exponent is applied to the spectrum to linearise the increasing region and obtain the threshold. The shift-log-log plot method is used when there is no a priori information and estimates the power exponent by a log-log plot taking into account the threshold. These methods were used to automatically estimate the threshold and power exponent from the photoelectron emission spectrum and the voltage-current spectrum.