Plasma diagnosis (RGA)

RGA

Ionization (by passing an electric current through the filament, accelerating the released hot electrons and colliding with neutrons or atoms). Quadruple mass filter consists of 4 parallel metal rods and makes 2 pairs by electrically connecting two opposite electrodes and applies voltages (DC, RF) of different polarities to each other. Ions of the selected mass (mass/charge) pass through the quadrupole with stable motion, but ions of other masses collide with the metal rod or leave the quadrupole. Passed ions reach the detector (Faraday cup & Secondary Electron Multiplier) and measure the ion current.