[Granted] A plasma ion implantation system includes a process chamber, a source for producing a plasma in the process chamber, a platen for holding a substrate in the process chamber and a pulse source for generating implant pulses for accelerating ions from the plasma into the substrate. In one aspect, the system includes a plasma monitor configured to measure ion mass and energy in the process chamber and an analyzer configured to determine an operating condition of the system in response to the measured mass and energy. In another aspect, the system includes a data acquisition unit configured to acquire samples of the implant pulses and analyzer configured to determine an operating condition of the system based on the acquired samples.