Subtraction of the background and automatic peak identification in gamma-ray spectra obtained from a Ge(Li) detector

Abstract

In this paper the identification of the peak area of γ-ray spectra, obtained from a Ge(Li) detector, was made by means of a χ 2test in the spectra, from which the background had already been subtracted. Preliminary subtraction of the background was done by a special procedure, similar to the process of differentiation in electronic circuits. After this operation the slow changing component was cut off, which corresponds to the subtraction of the background. The small residual background is similar to zero level restoration by a diode. This subtracting procedure does not use any information about peaks in the spectrum. After subtraction of the background, the identification of the peak area was made on the basis of counting rate deviation from zero. Then additional subtraction was done after identification. For this purpose the background in the peak area was represented by a polynomial of the third order, satisfying the boundary conditions at the end points of the peak.