title: [Spectrum diagnostic of arcjet].
abstract: Arcjet is a kind of propulsion device for mechanical operation and control of spacecraft. As its specific impulse is far greater than classical device using chemical propellant, arcjet is playing an increasing role in spacecraft propulsion. To improve our understanding of its working mechanics, the diagnostic method of arcjet is discussed and a set of spectrum diagnostic system is established in this paper. With this system, spectrum diagnostic was executed for Ar propellant at a setting value of flow rate and input current in a vacuum chamber. The result shows that the system has a high signal-to-noise ratio and the data collected can reflect the physical process objectively. Through transaction and analysis of these data, radial distribution of emission coefficient was obtained for different spectral lines, and radial distribution of temperature was also obtained through farther analysis of the emission coefficient. The result shows that under the experiment conditions of this paper, arcjet is in thermodynamic non-equilibrium state, therefore the temperatures obtained by different spectral lines are different.
authors.affiliation: Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China.
authors.forename: Wen-Hua
authors.initials: WH
authors.lastname: Zhao
authors.forename: Yan
authors.initials: Y
authors.lastname: Shen
authors.forename: Li-Ming
authors.initials: LM
authors.lastname: Chen