Analytical function for fitting peaks in alpha-particle spectra from Si detectors

Improved peak shape fitting in alpha spectra

“…Various peak models have been proposed in the past (Trivedi, 1969;Baba, 1978;Wätzig and Westmeier, 1978;García-Toraño and Aceña, 1981;L'Hoir, 1984;Bortels and Collaers, 1987;Koskelo et al, 1996;García-Toraño, 1997, 2003Lozano et al, 2000;Pommé and Sibbens, 2008;Semkow et al, 2010) and in recent work an attempt was made to include more physics in spectrum deconvolution (Siiskonen and Pöllänen, 2011;Westmeier and Siemon, 2012;Pöllänen and Siiskonen, 2014) or to use an artificial neural network (Baeza et al, 2011). One of the most successful analytical models to represent the shape of a mono-energetic alpha peak is the convolution of an exponential low-energy tail with a Gaussian distribution, as suggested by L'Hoir (1984) and introduced by Bortels and Collaers (1987) where A is the peak area, u À μ is the distance to the peak position, s is the standard deviation of the Gaussian and τ is the tailing parameter.…”

“…One of the most successful analytical models to represent the shape of a mono-energetic alpha peak is the convolution of an exponential low-energy tail with a Gaussian distribution, as suggested by L'Hoir (1984) and introduced by Bortels and Collaers (1987) where A is the peak area, u À μ is the distance to the peak position, s is the standard deviation of the Gaussian and τ is the tailing parameter. They obtained a better fit after pre-treating the spectrum by subtracting a long tail distribution and then fitting a mix of two exponential functions with different characteristic lengths, τ 1 and τ 2 , using normalised weighting factors η 1 and 1 À η 1 .…”

Precise Determination of the UnperturbedB8Neutrino Spectrum

“…The -particle energy peaks were fitted by using a Gaussian function folded with two exponential tails as described in Ref. [20], accounting for the straggling taking place in the dead layer of the DSSSD. The thickness of this dead layer was first measured by using an external source with different incidence angles.…”

Cryogenic micro-calorimeters for mass spectrometric identification of neutral molecules and molecular fragments

“…In contrast, however, this main peak now has a clear tail extending towards low energies, suggesting that a small but significant part of the ion kinetic energy was not detected for a noticeable fraction of events with heavier atomic ions. In order to quantitatively describe the resulting asymmetric peak shape we extend our analysis by fitting the spectra by a convolution of a Gaussian function and a left-sided exponential function 47,64 …”