The plume field in a vacuum facility for Hall thruster ground testing was investigated in detail through a series of simulations using direct simulation Monte Carlo (DSMC) code. The focus here was put on the effects of vacuum plume flow field in testing facility under different distributions of the xenon pump and beam baffle. The results showed that the position of xenon pump had little influence on the plume flow field. However

it should be considered that the xenon pump should be uniformly arranged to prevent locally excessive increase of pressure and formation of resistance. The beam baffle had an obvious inhibitory effect on the backflow particles

and had a good protection function for xenon pump. However

it also changed the plume flow field distribution

even the discharge characteristic and performances of Hall thruster. There were also some considerations for distribution of process equipments to reach a better and real testing environment. The numerical simulation is great beneficial to the design and layout optimization of test facility

which provides a more effective test environment for ground tests of electric propulsion.