  We carry out simulations of laser plasmas generated during UV nanosecond
pulsed laser ablation of the chalcogens selenium (Se) and tellurium (Te), and
compare the results to experiments. We take advantage of a 2D-axisymmetric,
adaptive Cartesian Mesh (ACM) framework that enables plume simulations out to
centimeter distances over tens of microseconds. Our model and computational
technique enable comparison to laser-plasma applications where the long-term
behavior of the plume is of primary interest, such as pulsed laser synthesis
and modification of materials. An effective plasma absorption term is
introduced in the model, allowing the simulation to be constrained by
experimental time-of-flight kinetic energy distributions. We show that the
effective simulation qualitatively captures the key characteristics of the
observed laser plasma, including the effect of laser spot size. Predictions of
full-scale experimentally-constrained Se and Te plasmas for 4.0 J/cm$^2$ laser
fluence and 1.8 mm$^2$ circular laser spot area show distinct behavior compared
to more commonly studied copper (Cu) plumes. The chalcogen plumes have spatial
gradients of plasma density that are steeper than those for Cu by up to three
orders of magnitude. Their spatial ion distributions have central bulges, in
contrast to the edge-only ionization of Cu. For the irradiation conditions
explored, the range of plasma temperatures for Se and Te is predicted to be
higher than for Cu by more than 0.50 eV.
