next up previous contents
Next: Spline Up: Multiplicative Model Components Previous: Redden

            smedge:  smeared edge

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

M(E) =

1                      E < Ec

exp[-f(E/E_c)^alpha]*[1-exp((E_c-E)/W)]  E >= E_c

where:

par1= Ec

the threshold energy (keV)

par2= f

the maximum absorption factor at threshold

par3= a

index for photo-electric cross-section (normally –2.67)

par4= W

smearing width (keV)