Design and manufacturing of a single Langmuir probe for plasma measurements in Hall effect thruster experiments

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Bilimleri Enstitüsü, Fen Bilimleri Enstitüsü, Türkiye

Tezin Onay Tarihi: 2014

Öğrenci: ÖZGE YAZICIOĞLU

Danışman: HÜSEYİN NAFİZ ALEMDAROĞLU

Açık Arşiv Koleksiyonu: AVESİS Açık Erişim Koleksiyonu

Özet:

Electric propulsion is a technology which has been tested on ground and in space since 1960s. The goal of electric propulsion systems is to achieve thrust with high exhaust velocities using electricity. To date, more than 200 electric thrusters have been flown and operated successfully onboard communication satellites and deep-space scientific missions for years with zero failure rate, making the technology more attractive in recent years. Thrust, specific impulse, total efficiency and plume divergence are some figures of merit for the performance of the thruster. Different probes are used in plasma measurements to evaluate and test the performance of the Hall Effect Thrusters. In this study, a Single Langmuir probe design is given for plasma measurements in low pressure. The basic working principle of Single Langmuir probe along with the criteria and measurement methodology applied in the design of the probe is also described. In addition, the technique that is used in the analysis of the current-voltage characteristics to determine the local plasma potential, electron number density and temperature is discussed in detail. Then, the designed probe was produced and used for plasma measurements in low pressure vacuum chamber. The results of measurements and the comparisons with that of Standard ALP System Langmuir Probe are presented in detail.