In order to evaluate the proportion of double ion ratio in ion engine beam rapidly

discharge chamber parameters were obtained through empirical theory

ratio of doubly/singly charged ions in beam was derived based on different generating processes of singly and doubly charged xenon ions. 20cm xenon ion thruster of Lanzhou Institute of Physics was tested and average fraction of doubly charged ions was acquired through E×B spectrometer. Xe++/Xe+ ratio under standard condition was measured to be 0.077

which was in good agreement with the analysis result of 0.071.