국내 최대 기계 및 로봇 연구정보

기술보고서

기술보고서 게시판 내용
타이틀	Modeling Neutral Densities Downstream of a Gridded Ion Thruster
저자	Soulas, George C.
Keyword	CYLINDRICAL BODIES;; ION ENGINES;; NEUTRALIZERS;; ORIFICES;; PREDICTIONS;; ROCKET THRUST;; SIMPLIFICATION;; VACUUM EFFECTS
URL	http://hdl.handle.net/2060/20110000536
보고서번호	NASA/TM-2010-216930
발행년도	2010
출처	NTRS (NASA Technical Report Server)
ABSTRACT	The details of a model for determining the neutral density downstream of a gridded ion thruster are presented. An investigation of the possible sources of neutrals emanating from and surrounding a NEXT ion thruster determined that the most significant contributors to the downstream neutral density include discharge chamber neutrals escaping through the perforated grids, neutrals escaping from the neutralizer, and vacuum facility background neutrals. For the neutral flux through the grids, near- and far-field equations are presented for rigorously determining the neutral density downstream of a cylindrical aperture. These equations are integrated into a spherically-domed convex grid geometry with a hexagonal array of apertures for determining neutral densities downstream of the ion thruster grids. The neutrals escaping from an off-center neutralizer are also modeled assuming diffuse neutral emission from the neutralizer keeper orifice. Finally, the effect of the surrounding vacuum facility neutrals is included and assumed to be constant. The model is used to predict the neutral density downstream of a NEXT ion thruster with and without neutralizer flow and a vacuum facility background pressure. The impacts of past simplifying assumptions for predicting downstream neutral densities are also examined for a NEXT ion thruster.