ISSN:
1089-7623
Source:
AIP Digital Archive
Topics:
Physics
,
Electrical Engineering, Measurement and Control Technology
Notes:
Energy spectra of 1 keV He+ and Ar+ ion beams have been investigated using a sector field analyzer with a resolution ΔE/E〈10−3. The ions were generated in a filament type plasma ion source with axial magnetic confinement. The energy spectra exhibited a unimodal, almost symmetrical peak. Width and position of the peak were measured as a function of the operating parameters of the ion source. The smallest energy spread of the ions was measured at relatively high source pressures and low magnetic field strength, in which case the full width at half-maximum of the peak was ΔE=1.5 eV. Correcting for the resolution of the analyzer, an energy spread of less than 1 eV thus appears to be achievable with the source employed in this study. Rather large peak shifts (up to 10 eV and more) were observed upon changing the axial magnetic field strength and the discharge current, the effect being much more pronounced for He than for Ar. By contrast, the peak position was almost independent of the applied discharge voltage, provided the terminal voltage was connected to the anode of the discharge. This implies that the zero point of the ion energy is closely related to the anode potential.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1142798
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