Application and development of the pulsed plasma thruster

An experimental study on the quasi-neutral beam extracted by a neutralizer-free gridded ion thruster prototype was presented. The prototype was designed using an inductively coupled plasma (ICP) source terminated by a double-grid accelerator. The beam characteristics were compared when the accelerator was radio-frequency (RF) biased and direct-current (DC) biased. An RF power supply was applied to the screen grid via a blocking capacitor for the RF acceleration, and a DC power supply was directly connected to the screen grid for the DC acceleration. Argon was used as the propellant gas. Furthermore, the characteristics of the plasma beam, such as the floating potential, the spatial distribution of ion flux, and the ion energy distribution function (IEDF) were measured by a four-grid retarding field energy analyzer. The floating potential results showed that the beam space charge is compensated in the case of RF acceleration without a neutralizer, which is similar to the case of classical DC acceleration with a neutralizer. The ion flux of RF acceleration is 1.17 times higher than that of DC acceleration under the same DC component voltage between the double-grid. Moreover, there are significant differences in the beam IEDFs for RF and DC acceleration. The IEDF of RF acceleration has a widened and multi-peaked profile, and the main peak moves toward the high-energy region with increasing the DC self-bias voltage. In addition, by comparing the IEDFs with RF acceleration frequencies of 3.9 MHz and 7.8 MHz, it is found that the IEDF has a more centered main peak and a narrower energy spread at a higher frequency.

Section: Introductionmentioning

confidence: 99%

Experimental study of a neutralizer-free gridded ion thruster using radio-frequency self-bias effect

Yang

Guo²,

Bai³

et al. 2023

“…The electric propulsion system has several advantages such as high specific impulse, long lifetime, repeatable start, low thrust, and high control accuracy. It can significantly increase the payload of spacecraft, extend their service life, and reduce their launch costs, it is therefore widely employed in microsatellites [1][2][3][4][5]. Regarding electric propulsion systems, the pulsed plasma thruster (PPT) is considered suitable for microsatellites owing to its simple structure, low cost, high specific impulse at low power and precise thrust.…”

Section: Introductionmentioning

confidence: 99%

Characteristics of plasma in a novel laser-assisted pulsed plasma thruster

Zhao¹,

Wu²,

Ou³

et al. 2022

A novel laser-assisted pulsed plasma thruster (LA-PPT) is proposed as an electric propulsion thruster, which separates laser ablation and electromagnetic acceleration. It aims for a higher specific impulse than that achieved with conventional LA-PPTs. Owing to the short-time discharge and the novel configuration, the physical mechanism of the discharge is unclear. Time and spatial-resolved optical emission spectroscopy was applied to investigate the variation in the plasma properties in the thruster discharge channel. The plasma species, electron temperature, and electron density were obtained and discussed. Our investigation revealed that there were H α , H β , H γ , H ε atoms, C I, C II, C III, C IV, Cl I, Cl II particles, and a small amount of CH, C3, C2, H2 neutral molecular groups in the plasma. The electron temperature of the discharge channel of the thruster was within 0.6–4.9 eV, and the electron density was within (1.1–3.0) × 1018 cm−3, which shows that the optical emission spectroscopy method is to measure the electron excitation temperature and electron density in heavy particles. But the Langmuir probe method is to measure the temperature and density of free electrons. The use of laser instead of spark plug as the ignition mode significantly changed the plasma distribution in the discharge channel. Unlike the conventional PPT, which has high electron density near the thruster surface, LA-PPT showed relatively large electron density at the thruster outlet, which increased the thruster specific impulse. In addition, the change in the ignition mode enabled the electron density in the LA-PPT discharge channel to be higher than that in the conventional PPT. This proves that the ignition mode with laser replacing the spark plug effectively optimised the PPT performance.

“…The application of plasma ignition in aero engines has attracted the attention of many researchers [5][6][7]. Plasma enhances the ignition and combustion effects through thermal, dynamic, and transport effects [8][9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Discharge and jet characteristics of gliding arc plasma igniter driven by pressure difference

Cheng¹,

Song²,

Huang³

et al. 2022

Stable combustion in an afterburner can help increase the thrust of the engine in a short time, thereby improving the maneuverability of a fighter. To improve the ignition performance of an afterburner, a twin-duct ignition platform was designed to study the performance of a gliding arc plasma igniter in a close-to-real afterburner condition. The research is carried out by a combination of experiments and simulations. The working environment of the igniter was explored through a numerical simulation. The results showed that the airflows ejected from the radiating holes formed a swirling sheath, which increased the anti-interference ability of the airflows jet. The influence of the pressure difference between the inlet and outlet of the igniter (∆p), the flow rate outside the igniter outlet (W2), and the installation angle (α) on the single-cycle discharge energy (E) as well as the maximum arc length (L) was studied through experiments. Three stages are identified: the airflows breakdown stage, the arc evolution stage, and the arc fracture stage. E and L increase by 107.3% and 366.2%, respectively, with ∆p increasing from 10 to 70 Torr. The relationship between L and ∆p obtained by data fitting is L=3-2.47/(1+(∆p/25)4). The relationship of L at different α is Lα=0°> (Lα=45° and Lα=135°) > Lα=180°> Lα=90°. E and L decreased by 18.2% and 37.3%, respectively, when ∆p=45 Torr and W2 is increased from 0 to 250 SLM.