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The beam profile measurements were made with a Plasma Ion Source with standard
ion optics. A Faraday cup was used as detector having a 2mm2 aperture. The Faraday cup was mounted on a precision manipulator at a distance of 100mm. The Faraday cup was biased to utmost avoid an influence of electrons while measuring the ion current.
Parameters:
・ Ua: Anode Voltage (positiv)
・ Ue: Extractor Voltage (negativ)
・ Ug: Bias Voltage to repel electrons (negativ)
・ pK: chamber pressure.
・ IMag: input current to the magnetron. (mA)
For all figures, if not otherwise specified:
・ magnetron current (Imag) = 50mA
・ The extractor voltage (Ue) is selected such that the ion current is maximal in the center of the beam. The value varies form about 50V to 1000V.
・ The bias voltage (Ug)is -100V for the ion energies 0V and 50V (plus plasma
potential). For all other cases the bias voltage is -500V.
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