Theoretical computation on the contamination of vacuum plume in the backflow region
School of Astronautics, Beijing Univ of Aeronautics and Astronautics, Beijing 100083, China;School of Astronautics, Beijing Univ of Aeronautics and Astronautics, Beijing 100083, China;School of Astronautics, Beijing Univ of Aeronautics and Astronautics, Beijing 100083, China;Lanzhou Inst of Physics, Lanzhou 730000, China