smedge: smeared edge

A smeared edge (Ebisawa PhD thesis, implemented by Frank Marshall).


\begin{displaymath}
M(E) = \begin{array}{ll}
1 & E < E_c\\ [.2cm]
\exp\left[-f...
...ight] \left[1-\exp((E_c-E)/W)\right]
& E \geq E_c
\end{array}\end{displaymath}

where:

par1=$E_c$ the threshold energy (keV)
par2=f the maximum absorption factor at threshold
par3=$\alpha$ index for photo-electric cross-section (normally -2.67)
par4=W smearing width (keV)