Low-frequency oscillations in Hall thrusters

Abstract

In this paper, we summarize the research development of low-frequency oscillations in the last few decades. The findings of physical mechanism, characteristics and stabilizing methods of low-frequency oscillations are discussed. It shows that it is unreasonable and incomplete to model an ionization region separately to analyze the physical mechanism of low-frequency oscillations. Electro-dynamics as well as the formation conditions of ionization distribution play an important role in characteristics and stabilizing of low-frequency oscillations. Understanding the physical mechanism and characteristics of low- frequency oscillations thoroughly and developing a feasible method stabilizing this instability are still important research subjects.

Application of an Electric Field to Low-Frequency Oscillation Control in Hall Thrusters

“…Therefore, the variation in frequency may not affect the controllability of the controller stage. [10,12,33] The analysis can also be verified by the experimental data for a turnover frequency 35 kHz as shown in Figure 12. The current oscillation in Figure 12 was measured between the filter and thruster.…”

“…Therefore, we designate the filter stage as the controller stage. The controller stage filter regulates the voltage across itself according to the variation of discharge current, so as to affect the electric field distribution in the discharge channel and therefore decrease the discharge current fluctuation in the discharge circuit [8,10,12,26,33]. The simplest component that can provide a varying voltage with a change in current is an inductor.…”

“…Parts of this chapter are reproduced from authors' recent publication [4,10,12]. The authors would like to acknowledge the support of the National Natural Science Foundation of China (No.…”

“…Researchers have recognized the low-frequency oscillation phenomena with Hall thrusters since the early 1970s [11]. Even now, research on this subject is ongoing [12].…”

Numerical study of low-frequency discharge oscillations in a 5 kW Hall thruster

“…Subsequently, the low-frequency oscillations have been well reproduced by numerous time-dependent numerical models [8][9][10]. Recently, Barral, Yu, Wei, and Wang et al have conducted considerable research [11][12][13][14][15][16][17][18][19][20][21][22][23] on the influencing factors, physical mechanisms, and stability of low-frequency oscillations.…”