Mixed-gas species plasma source system

An ion beam system comprising:

• a plasma source chamber configured to generate a plasma from a gas mixture;
• a plurality of gas reservoirs each storing a respective gas species;
• a plurality of controllers configured to independently control flow rates of the respective gas species into the plasma source chamber;
• a measuring unit configured to measure an ion ratio of an ion beam extracted from the plasma;
• and
• a computer system in communication with the plurality of controllers and the measuring unit, the computer system configured to:
• receive a desired ion ratio,
• predict a gas mixture composition corresponding to the desired ion ratio,
• control the plurality of controllers to generate the predicted gas mixture composition,
• receive a measured ion ratio from the measuring unit,
• compare the measured ion ratio to the desired ion ratio, and
• upon determining that the measured ion ratio deviates from the desired ion ratio, adjust at least one input parameter to reduce the deviation.

A non-transitory computer-readable medium storing instructions that, when executed by one or more processors, cause an ion beam system to:

• receive a desired ion ratio;
• predict a gas mixture composition configured to produce the desired ion ratio;
• control a plurality of controllers to introduce a plurality of gas species into a plasma source chamber according to the predicted gas mixture composition;
• receive measurements of an ion ratio of an extracted ion beam from the plasma source chamber;
• determine whether the measured ion ratio deviates from the desired ion ratio;
• and
• upon determining that the measured ion ratio deviates from the desired ion ratio, adjust at least one input parameter of the ion beam system to reduce the deviation.