A plasma treatment system (10) and related methods for rapidly treating a workpiece (56) with ions from a plasma having an ion density that is reproducibly uniform and symmetrical. The processing chamber (12) of the plasma treatment system (10) includes a chamber (14) lid having a symmetrical array of apertures (192) and further includes a vacuum distribution baffle (180), which are both configured to uniformly disperse a process gas adjacent the surface of the workpiece (56). The uniform dispersion of process gas and a symmetrical placement of the workpiece within the chamber (12) contribute to providing a uniformly dense plasma of ions adjacent the workpiece (56). A treatment system control (304) automates the operation of the system and controls the flow of process gas, evacuation of the chamber, and the application of the plasma excitation power to minimize the length of a treatment cycle and to optimize the uniformity of the plasma treatment.