  Within the Unified ternary fission model (UTFM), the alpha accompanied
ternary fission of even-even $^{244-260}$Cf isotopes has been studied by taking
the interacting barrier as the sum of Coulomb and proximity potential. For the
alpha accompanied ternary fission of 244^Cf isotope, the highest yield is
obtained for the fragment combination 108^Ru+4^He+132^Te, which contain near
doubly magic nuclei 132^Te (N=80, Z=52). In the case of 246^Cf and 248^Cf
isotopes, the highest yield is obtained for the fragment combinations with near
doubly magic nuclei 134^Te (N=82, Z=52) as the heavier fragment. The highest
yield obtained for 250^Cf, 252^Cf, 254^Cf, 256^Cf, 258^Cf and 260^Cf isotopes
is for the fragment combination with doubly magic nuclei 132^Sn (N=82, Z=50) as
the heavier fragment. We have included the effect of deformation and
orientation of fragments and this has revealed that in addition to closed shell
effect, ground state deformation also plays an important role in the
calculation of relative yield of favorable fragment combinations. The computed
isotopic yields for alpha accompanied ternary fission of 252^Cf isotope are
found to be in agreement with the experimental data. The emission probability
and kinetic energy of long range alpha particle is calculated for the various
isotopes of Cf and are found to be in good agreement with the experimental
data.
