Suchergebnisse

Proceeding of: 35th International Electric Propulsion Conference (IEPC), October 8-12, Atlanta, Georgia, USA ; Laser-induced fluorescence (LIF) is a non-intrusive technique that can provide useful information on ion production and acceleration in electric propulsion system. In this paper, spatially resolved LIF measurements of Xe+ are performed in the plume of an electron cyclotron resonance plasma thruster. The mapping of ion velocity distribution function in the magnetic nozzle shows that the ions are accelerated over a distance greater than 12 cm. A mean axial velocity up to 16 km/s has been obtained at 1 sccm and 26 W. The acceleration of ions is compared for different xenon flowrates. ; This work was made in the framework of project MINOTOR that has received funding from the European Union's Horizon H2020 research and innovation programme under grant No 730028.

Experimental characterization of plasma properties along the magnetic nozzle of an electron cyclotron resonance thruster is presented here. A permanent magnet (PM) prototype and a solenoid prototype are tested, whose main difference relies on the magnetic field strength and topology. A cylindrical Langmuir probe is used to measure plasma potential, plasma density and electron temperature. In the PM thruster setup, a laser induced fluorescence diagnostics is performed simultaneously with the Langmuir probe to measure the mean ion kinetic energy, and a Faraday gridded probe to characterize the angular plasma beam. An effective electron cooling rate has been identified, as well as the dependence of the total plasma potential drop with the mass flow rate. Results are compared with a supersonic collisionless fluid-kinetic 1D model where electron dynamics account for magnetic mirror effects and potential barriers, while ions are treated as a fluid cold species. The comparison allows to estimate the sonic transition of the plasma flow. ; The authors want to thank Mick Wijnen for his insightful comments and discussions. A preliminary version of this manuscript obtained the best PhD Communication Award at the Space Propulsion Conference 2018, 14–18 May, Seville. This work was made in the framework of project MINOTOR that has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No. 730028. Minor support came from the Spanish R & D National Plan (Grant No. PN ESP2016-75887).

Proceeding of: Space Propulsion Conference, SP 2018,14-18 mayo, Sevilla ; This paper presents experimental results on the magnetic nozzle of the 50 W Electron Cyclotron Resonance (ECR) thruster of ONERA, consisting of a 27 mm diameter ECR cavity and a fully divergent magnetic nozzle, created by a Neodymium permanent magnet. The diagnostics installed are a cylindrical Langmuir probe to measure plasma potential, plasma density and electron temperature, and a Laser Induced Fluorescence set-up to measure the mean ion kinetic energy. Both the ion velocity and plasma potential profiles seem to be independent of the mass flow rate when normalized with the electron temperature estimated at the sonic transition of the plasma flow. This sonic transition appears to be slightly shifted downwards of the thruster exit. Results are compared with a supersonic collisionless kinetic 1D model where electron dynamics account for magnetic mirror effects and potential barriers, while ions are treated as a fluid cold species. ; This work was made in the framework of project MINOTOR that has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 730028. This work was additionally supported by the Spanish R D National Plan (Grant No. ESP2013-41052-P).

Proceeding of: 35th International Electric Propulsion Conference (IEPC), October 8-12 2017, Atlanta, Georgia, USA ; This work presents experimental measurements along the magnetized plume of the ECR thruster developed by ONERA. Langmuir probes are used to determine the electron energy probability function (eepf) at different axial positions, revealing the non-local character of the distributions. The second part of the paper details a combined diagnostics of non-intrusive diamagnetic loop measurements and laser induced fluorescence to estimate the perpendicular electron temperature inside the plasma source. Averaged perpendicular electron pressure, plasma density, ion velocity at the exit plane and perpendicular electron temperature are determined as functions of the mass flow rate. ; This work was made in the framework of project MINOTOR that has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 730028.

Electric propulsion has been identified by European actors as a strategic technology for improving competitiveness in different space areas such as in-space operations and transportation. The European Commission has set up the "In-space Electrical Propulsion and Station-Keeping" Strategic Research Cluster (SRC) in the "Horizon 2020" funding framework with the goal of enabling major advances in Electric Propulsion for in-space operations and transportation. In this framework, the MINOTOR project was funded to mature a potentially disruptive cathodeless electric propulsion technology, the Electron Cyclotron Resonance (ECR) thruster. In recent years, the consortium leader ONERA has built up a large experience on ECR technology for electric propulsion, and the MINOTOR project will bring the expertise from three industrial partners (TMI, TAS-B and SAFRAN) and two university partners (UC3M and JLU) to take the next step. ; This work was made in the framework of project MINOTOR that has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 730028.