Match Tuner: Getting the Power Into the Plasma

A generator can only deliver its power if the load looks right. Tune the match and watch reflected power collapse — or detune it and watch the plasma starve while the cable takes the difference.

Schematic teaching model. The physics shown is real — power accepted by the load = forward × (1 − |Γ|²); cable, matchbox, and electrode losses then take a further share before the plasma’s, a standing wave grows on the line as the reflection coefficient |Γ| rises, and a resonant kHz transformer delivers peak power at its natural frequency f₀ — but the knob-to-impedance mapping, Q factor, and percentages are illustrative, not a circuit solver. Real matching also drifts as the plasma itself changes with power, pressure, and chemistry.