Supersonic plasma beams with controlled speed generated by the alternative low power hybrid ion engine (ALPHIE) for space propulsion

Abstract

The characteristics of supersonic ion beams from the alternative low power hybrid ion engine (ALPHIE) are discussed. This simple concept of a DC powered plasma accelerator that only needs one electron source for both neutral gas ionization and ion beam neutralization is also examined. The plasma production and space charge neutralization processes are thus coupled in this plasma thruster that has a total DC power consumption of below 450 W, and uses xenon or argon gas as a propellant. The operation parameters of the plasma engine are studied in the laboratory in connection with the ion energy distribution function obtained with a retarding-field energy analyzer. The ALPHIE plasma beam expansion produces a mesothermal plasma flow with two-peaked ion energy distribution functions composed of low and high speed ion groups. The characteristic drift velocities of the fast ion groups, in the range 36.6–43.5 Km/s, are controlled by the acceleration voltage. These supersonic speeds are higher than the typical ion sound velocities of the low energy ion group produced by the expansion of the plasma jet. The temperatures of the slow ion population lead to ion Debye lengths longer than the electron Debye lengths. Furthermore, the electron impact ionization can coexist with collisional ionization by fast ions downstream the grids. Finally, the performance characteristics and comparisons with other plasma accelerator schemes are also discussed.

Plasma Thrusters for In-Space Propulsion; New Trends and Physical Limitations

“…7. 5 The ion velocity distribution functions measured along the Z axis of symmetry of a plasma thruster [16,17].…”

Numerical Aspects of Particle-in-Cell Simulations for Plasma-Motion Modeling of Electric Thrusters

“…Electric thrusters have aroused much interest in space applications in recent years [1]. The most attractive characteristic of this kind of propulsion is the capability to deliver a very high specific impulse [2,3] and potentially long service life [4,5]. These features are essential for many futuristic, but not far, missions, as well as the building of a near-Earth satellite infrastructures, or the colonization of the Moon and Mars [6][7][8].…”

Propagator integral method for plasma physics kinetic equations with practical applications

“…This type of plasma is widely used for surface treatment [5,6], electric propulsion [8] and medicine [57]. Its dynamics is of main interest in this dissertation to develop and solve kinetic models that improve the understanding of plasmas generated in the low temperature plasma laboratory of the UPM PlasmaLab 1 , along with the improvement of the ALPHIE electric thruster [100,127].…”

“…In particular, we pay attention to the plasma plume generated by ALPHIE (Alternative Low Power Hybrid Ion Engine) [100,127] of figure 7.1, a low power ion thruster in current development by the UPM PlasmaLab. This thruster consists on a set of magnetic crowns that generate a field inside the chamber to trap electrons coming from the active cathode neutraliser that ionize the neutral gas introduced through the inlet.…”

“…Hence, it is useful to firstly present some of the results obtained by the experimental team of the UPM PlasmaLab by means of a Retarding Potential Analyser (RPA) [118,127]. Main results are summarised in figure 7.2.…”