Right skew peak function
Right skew is the third peak function, and its integral will also be summed up to the peak area. Right skew is not included by HyperLab's predecessors, but it is present in HyperLab to allow better deconvolution. It may be of great importance, because skewness on the high energy side of the peak quite frequently occurs in practice (e.g. in short time activation analysis) due to pile-up effects. Right skew is very similar to Left skew which is at the low-energy side of a Gaussian, but it is mirrored to that (its flat part is on the high-energy side).
Because it is originated from a convolution of a Gaussian and an exponential, which decreases starting from the Gaussian's centroid, it is an asymmetric function. Therefore when the right skew is added to a Gaussian peak, it causes slight increase at the high energy side of the peak.
The fitted parameters for Right skew are the Right Skew Amplitude (relative to the Gaussian's amplitude), and the Right Skew Slope. The width of the right skew is not fitted, but assumed to be always equal to the width of the Gaussian. The picture shows a right skew with Slope=1 and relative Amplitude=0.25.
Right skew's counts may be calculated by the following formula at channel x:
Right Skew Amplitude relative to that of Gaussian (may vary from 0.0 to 0.75)
Right Skew Slope (0.3 – 2.0)
Amplitude of Gaussian
Position of the Gaussian centroid
Gaussian width (Width = FWHM/1.66),
and erfc is the standard complementary error function.
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