Effects of unsymmetrical magnetic field on discharge characteristics of Hall thruster with large height-radius ratio

Fan, Haotian; Xu, Yunan; Wang, Lei; Wei, Liqiu; Li, Hong; Guo, Ning; Ding, Yongjie

doi:10.1016/j.vacuum.2022.111261

Cited by 6 publications

(3 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As the cathode flow rate decreased, the CEES deteriorated, that is, I e decreased, resulting in a decrease in I. However, the proportion of I e is very small, less than 20% [36][37][38], so the reduction of I e has a relatively small impact on I, and the reduction of I and P is too small. Simultaneously, observing carefully at figure 3, when the cathode flow rate is reduced to 0.8 sccm, although I and P are still smaller than the steady-state values, its show a slight upward trend, indicating that I and P are not monotonic functions of the cathode flow rate.…”

Section: Resultsmentioning

confidence: 99%

“…After the ionization process is successfully established, the cathode provides electrons to neutralize the plume. Less than 20% [36][37][38] of the electrons in the discharge current enter the channel, and the remaining electrons that maintain ionization are primarily generated by collision ionization and secondary electrons emitted from the wall. Combined with figure 9, it can be seen that the electrons entering the thruster from the cathode travel the farthest path, have the largest potential drop, and obtain the highest energy; however, their number is extremely small.…”

Section: Discussion and Analysismentioning

confidence: 99%

See 1 more Smart Citation

Indicator of abnormal cathode electron emission state with gas flow in Hall thrusters

Li,

Zhou,

et al. 2024

J. Phys. D: Appl. Phys.

Self Cite

View full text Add to dashboard Cite

The accurate diagnosis of abnormal electron emission state in hollow cathodes is crucial for the stable operation of Hall electric propulsion systems. In this study, a method of reducing the cathode working gas flow rate was used to simulate abnormal working conditions in which the cathode electron emission state (CEES) was deteriorating. By analyzing and comparing the oscillation signals under abnormal and steady-state working conditions, it was found that as the CEES deteriorated, the power content of the breathing oscillation decreased in the 1–40 kHz frequency band, and the main frequency decreased; in contrast, the power content of the transit-time oscillation increased in the 100–500 kHz range, and the main frequency was on the rise. Combined with the current growth rate analysis of breathing and transit-time oscillations, when the cathode gas flow rate decreases, the CEES deteriorates, the coupling voltage drop increases, and the potential drop in the channel decreases. The electron temperature and nonlinear power absorption of the electrons decrease, leading to a decrease in the growth rate of breathing oscillations and the breathing oscillation weakens; however, the time-averaged ion velocity and ion sound velocity in the channel decrease simultaneously, but the ion velocity decreases significantly faster than the ion sound velocity, leading to an increase in the growth rate of the transit-time oscillation, and the transit-time oscillation strengthen. Through comparison of the oscillation signals under different working conditions, such as varied anode flow rate, anode voltage, magnetic induction, it was proven to be a unique feature of CEES deteriorates, and can be used as an indicator of CEES deteriorates during the on-orbit operation of the Hall-effect thrusters.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Discussion and Analysismentioning

confidence: 99%

Indicator of abnormal cathode electron emission state with gas flow in Hall thrusters

Li,

Zhou,

et al. 2024

J. Phys. D: Appl. Phys.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The working principle of Hall thruster determines that the most effective way to improve the specific impulse is to increase the discharge voltage [6,7], which has been verified on many types of Hall thrusters, including SPT-1 [8] in Russia, PPS ® X000 [9] in France, NASA-173Mv2 [10] in the United States, and so on. Previous research results show that the specific impulse of Hall thruster with large height-radius ratio will also increase with the increase of discharge voltage, but it is difficult to maintain high efficiency under high voltage [11]. In the process of pursuing higher specific impulses, the demand for electric energy of propulsion system has increased greatly.…”

Section: Introductionmentioning

confidence: 99%

Magnetic field optimization of hall thruster with large height-radius ratio for high specific impulse operation

Fan

Wang

et al. 2023

Phys. Scr.

Self Cite

View full text Add to dashboard Cite

Hall thrusters with large height-radius ratio not only have incalculable application values in reducing the volume and weight of thrusters, but also have the potential advantages of higher discharge performance and longer service life. However, the lower propellant density in the main ionization zone and the higher electron temperature in the channel aggravate the loss of propellant and current under high voltage, and significantly reduce the discharge efficiency under high specific impulse mode. To improve the discharge performance of Hall thrusters with large height-radius ratio under high voltage, an optimization scheme of internally loaded magnetic field was proposed in this work. The simulation results show that under the internally loaded magnetic field, both the ionization zone and the acceleration zone move toward the inside of the channel. Although the ion loss on the walls increases, the higher propellant density at the channel upstream greatly promotes the increase of ionization rate and significantly improves the propellant utilization efficiency. The second zone crossed by magnetic field lines in the channel can be established by the internally loaded magnetic field, which enhances the magnetic field intensity on the inner and outer walls, and reduces the electron temperature near the channel outlet significantly. So that the axial conduction of electrons is effectively restrained and the current utilization efficiency is greatly improved. With the introduction of internally loaded magnetic field, the total efficiency of HEP-1350PM can be increased by 7.2% at 400 V. Moreover, the performance optimization effect brought by the internally loaded magnetic field will be gradually amplified with the increase of discharge voltage, which makes the Hall thruster with large height-radius ratio expected to achieve high-efficiency discharge under higher specific impulse.

show abstract

The effect of magnet core size on the performance of a cylindrical Hall thruster with the near-anode cusp magnetic field

Gao

Wang

Hu³

et al. 2022

Vacuum

View full text Add to dashboard Cite

Effects of unsymmetrical magnetic field on discharge characteristics of Hall thruster with large height-radius ratio

Cited by 6 publications

References 22 publications

Indicator of abnormal cathode electron emission state with gas flow in Hall thrusters

Indicator of abnormal cathode electron emission state with gas flow in Hall thrusters

Magnetic field optimization of hall thruster with large height-radius ratio for high specific impulse operation

The effect of magnet core size on the performance of a cylindrical Hall thruster with the near-anode cusp magnetic field

Contact Info

Product

Resources

About