CCD images of Hall effect thruster plume dynamics after ultrafast current ignition

Abstract

The dynamic behavior of the Hall effect thruster plasma plume is investigated after ultrafast current ignition driven by a metal-oxide-semiconductor field-effect transistor MOSFET power switch. Time-resolved optical measurements performed with a gated intensified charged coupled device (CCD) camera allow to reconstruct the plume temporal features. Images of the ion beam reveal oscillations in plasma light intensity linked to "breathing" instabilities. The observed periodic variations of the beam divergence originate from the displacement of the ionization layer within the thruster magnetic barrier.

Investigation of the Start Transient in a Hall Thruster

“…The simulated results are approximately in accordance with the experimental result in Ref. [3] and [4]. The periodic oscillations after the current peak are directly connected with the so-called "breathing" mode [20,21], which is caused by the ionization and subsequent acceleration of ions created within the channel.…”

Измерения Колебаний Дрейфового Тока В Двигателях С Замкнутым Дрейфом Электронов

“…Так как тяга пропорциональна ионному току, при больших токах возможны ситуации, когда искажение магнитного поля будет велико. Например, в момент зажигания разряда, когда ток на порядок превышает номинальный [7][8][9], или при достаточно сильных коле-баниях. Кроме того, в ряде случаев разряды такого типа могут переходить в неустойчивый режим при неболь-ших отклонениях магнитного поля ((1−2) · 10 −3 Gs) от номинального.…”

Improvement of the low frequency oscillation model for Hall thrusters

“…The amplitude and the frequency of this low frequency oscillation are affected by the operating parameters, 2-5 and they are related to the working performance of the thruster. [6][7][8] Many experiments and numerical analyses have been performed in the study of the low frequency oscillation mechanism and characteristics. An early model was proposed by Morozov; this model focuses on the main low frequency oscillation mechanism, while ignoring the electron energy equation and simplifying the electron transport characteristics.…”