  Static fission barriers for 95 even-even transuranium nuclei with charge
number $Z=94-118$ have been systematically investigated by means of pairing
self-consistent Woods-Saxon-Strutinsky calculations using the potential energy
surface approach in multidimensional ($\beta_2$, $\gamma$, $\beta_4$)
deformation space. Taking the heavier $^{252}$Cf nucleus (with the available
fission barrier from experiment) as an example, the formation of the fission
barrier and the influence of macroscopic, shell and pairing correction energies
on it are analyzed. The results of the present calculated $\beta_2$ values and
barrier heights are compared with previous calculations and available
experiments. The role of triaxiality in the region of the first saddle is
discussed. It is found that the second fission barrier is also considerably
affected by the triaxial deformation degree of freedom in some nuclei (e.g.,
the $Z=112-118$ isotopes). Based on the potential energy curves, general trends
of the evolution of the fission barrier heights and widths as a function of the
nucleon numbers are investigated. In addition, the effects of Woods-Saxon
potential parameter modifications (e.g., the strength of the spin-orbit
coupling and the nuclear surface diffuseness) on the fission barrier are
briefly discussed.
