Device for reducing the impact on a surface section by positively charged ions, and ion accelelerator arrangement

A spacecraft having a mass potential and comprising:

• first outside surfaces lying at the mass potential;
• and
• an ion accelerator arrangement comprising:
• an ionization chamber having a beam exit opening and generating ions from a working gas introduced into the ionization chamber;
• an electrode arrangement configured to electrostatically accelerate the generated ions via a static high voltage, to electrostatically eject from the beam exit opening the generated ions as a plasma beam, and to supply electrons to the ionization chamber for the ionization in the ionization chamber;
• and
• a shielding surface laterally offset relative to the beam exit opening, surrounding the beam exit opening, and facing the ejected plasma beam during operation of the ion acceleration arrangement, said shielding surface having a funnel-shaped body with a smooth surface facing the ejected plasma beam, wherein said funnel-shaped body consists of metal that is not soft magnetic and does not influence a magnetic field, or of a dielectric;
• wherein the shielding surface lies spatially between the ejected plasma beam and the first outside surfaces;
• wherein the shielding surface lies electrically at a potential separated from the mass potential of the spacecraft;
• and
• wherein the ion accelerator arrangement reduces impact of positively charged ions of the ejected plasma beam on a surface section of the spacecraft.