  The universal curve is one of the simple ways to get preliminary information
about the Alpha-decay half-life times of heavy nuclei. We try to find
parameterization for the universal curve of Alpha decay based on
semi-microscopic calculations, starting from the realistic M3Y-Reid
nucleon-nucleon interaction. Within the deformed density-dependent cluster
model, the penetration probability and the assault frequency are calculated
using the WKB penetration probability. The deformations of daughter nuclei and
the ground-state spin and parity of the involved nuclei are considered. We
found that it is accurate enough to express the assault frequency, for all
studied decays, either as a function of the mass number of the parent nuclei or
as a constant average value. The average preformation probability of the Alpha
cluster inside four groups of 166 even(Z)-even(N), 117 odd-even, 141 even-odd,
and 72 odd-odd Alpha-emitters are obtained, individually. The effect of
participating unpaired nucleons in the involved nuclei, as well as the
influence of any differences in their ground-state spin and/or parity, appears
in the obtained average values of the preformation probability. Based on the
calculated WKB penetration probability, we suggested a single universal curve
for Alpha decay, with only one parameter. This parameter varies according to
the classified four groups. It includes the preformation probability and the
average assault frequency, in addition to the pairing contribution.
