  We carry out the first 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 novel computational technique enable direct comparison to laser-plasma
applications where the long-term behavior of the plume is of primary interest,
such as time-of-flight measurements and pulsed laser materials synthesis. 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$^2$ 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 noticeable contrast to the edge-only
ionization of Cu. Finally, for the irradiation conditions used, the range of
plasma temperatures for Se and Te is predicted to be higher than for Cu by more
than 0.50 eV.
