The invention discloses an
active control method for the surface potential of a
spacecraft, which can correct the current balance on the surface of the
spacecraft by emitting positive
ion beams, reduce the surface potential of the
spacecraft, avoid the phenomenon of unequal charging, and also reduce the disturbance of photoelectrons to
plasma ions and electrons. The measured energy band is close to the measurement limit of the instrument, improving the stability and accuracy of the measurement; the active potential control method can control the positive potential and the
negative potential at the same time, so it has a wider range of applications; when controlling the
negative potential, By setting two thresholds, the
lower limit of the preset surface potential V 2 and preset potential V 3 , to control the startup and shutdown of the
liquid metal ion source respectively. Since there is a certain difference between the two thresholds, after the
liquid metal ion source is turned on, it emits a positive
ion flow to increase the surface potential. After a period of time, the surface potential reaches the preset potential V 3 , the
liquid metal ion source is turned off, therefore, this method will not cause frequent start-up of the liquid
metal ion source, which plays an important role in prolonging its life and improving its stability.