Forum für Wissenschaft, Industrie und Wirtschaft

Hauptsponsoren:     3M 
Datenbankrecherche:

 

Magnetic Shielding of Ion Beam Thruster Walls

15.02.2013
Electric rocket engines known as Hall thrusters, which use a super high-velocity stream of ions to propel a spacecraft in space, have been used successfully onboard many missions for half a century.

Erosion of the discharge channels walls, however, has limited their application to the inner solar system. A research team at Caltech’s Jet Propulsion Laboratory, in Pasadena, Calif., has found a way to effectively control this erosion by shaping the engine’s magnetic field in a way that shields the walls from ion bombardment.

Ions are produced in Hall thrusters when electrons from an electric current collide with the propellant atoms to form a plasma in the discharge chamber. Thrust is then generated by the interaction of this current with an applied magnetic field that creates a strong electric field. The magnetic field is mostly perpendicular to the channel walls whereas the electric field is mostly parallel to the walls. This electric field then acts as the driving force on the ions, accelerating them to very high speeds (>45,000 mph) toward the exhaust opening. However, the presence of a plasma in the thruster’s discharge chamber leads also to a small component of the electric field parallel to the magnetic field lines.

This component then accelerates some ions toward the discharge chamber (rather than the exhaust opening) causing erosion by sputtering material from the walls. Guided by theory and numerical simulations, the research team designed a thruster configuration in which the effect of the plasma on the magnetic field lines along the walls is minimized, forcing the electric field to be perpendicular to the lines. Based on the numerical predictions, the effect of this magnetic field topology would be to accelerate ions away from walls while also significantly reducing their energy adjacent to the walls. Erosion then would be reduced without degrading propulsive performance. The method now known as magnetic shielding was verified by experiments in a vacuum facility using a modified thruster. The combined results of the simulations and experiments demonstrated that there was 100 to 1,000 times less wall erosion when using magnetic shielding. The results were published in the American Institute of Physics (AIP) journal Applied Physics Letters.

Article: “Magnetic shielding of walls from the unmagnetized ion beam in a Hall thruster” is published in the journal Applied Physics Letters.

Link: http://apl.aip.org/resource/1/applab/v102/i2/p023509_s1

Authors: Ioannis G. Mikellides (1), Ira Katz (1), Richard R. Hofer (1), and Dan M. Goebel (1).

(1) Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California

Catherine Meyers | Newswise
Further information:
http://www.aip.org

More articles from Physics and Astronomy:

nachricht Basque researchers turn light upside down
23.02.2018 | Elhuyar Fundazioa

nachricht Attoseconds break into atomic interior
23.02.2018 | Max-Planck-Institut für Quantenoptik

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Vorstoß ins Innere der Atome

Mit Hilfe einer neuen Lasertechnologie haben es Physiker vom Labor für Attosekundenphysik der LMU und des MPQ geschafft, Attosekunden-Lichtblitze mit hoher Intensität und Photonenenergie zu produzieren. Damit konnten sie erstmals die Interaktion mehrere Photonen in einem Attosekundenpuls mit Elektronen aus einer inneren atomaren Schale beobachten konnten.

Wer die ultraschnelle Bewegung von Elektronen in inneren atomaren Schalen beobachten möchte, der benötigt ultrakurze und intensive Lichtblitze bei genügend...

Im Focus: Attoseconds break into atomic interior

A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.

In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...

Im Focus: Good vibrations feel the force

Eine Gruppe von Forschern um Andrea Cavalleri am Max-Planck-Institut für Struktur und Dynamik der Materie (MPSD) in Hamburg hat eine Methode demonstriert, die es erlaubt die interatomaren Kräfte eines Festkörpers detailliert auszumessen. Ihr Artikel Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, nun online in Nature veröffentlich, erläutert, wie Terahertz-Laserpulse die Atome eines Festkörpers zu extrem hohen Auslenkungen treiben können.

Die zeitaufgelöste Messung der sehr unkonventionellen atomaren Bewegungen, die einer Anregung mit extrem starken Lichtpulsen folgen, ermöglichte es der...

Im Focus: Good vibrations feel the force

A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.

By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...

Im Focus: Verlässliche Quantencomputer entwickeln

Internationalem Forschungsteam gelingt wichtiger Schritt auf dem Weg zur Lösung von Zertifizierungsproblemen

Quantencomputer sollen künftig algorithmische Probleme lösen, die selbst die größten klassischen Superrechner überfordern. Doch wie lässt sich prüfen, dass der...

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

VideoLinks
Industrie & Wirtschaft
Veranstaltungen

Von festen Körpern und Philosophen

23.02.2018 | Veranstaltungen

Spannungsfeld Elektromobilität

23.02.2018 | Veranstaltungen

DFG unterstützt Kongresse und Tagungen - April 2018

21.02.2018 | Veranstaltungen

VideoLinks
Wissenschaft & Forschung
Weitere VideoLinks im Überblick >>>
 
Aktuelle Beiträge

Vorstoß ins Innere der Atome

23.02.2018 | Physik Astronomie

Wirt oder Gast? Proteomik gibt neue Aufschlüsse über Reaktion von Rifforganismen auf Umweltstress

23.02.2018 | Biowissenschaften Chemie

Wie Zellen unterschiedlich auf Stress reagieren

23.02.2018 | Biowissenschaften Chemie

Weitere B2B-VideoLinks
IHR
JOB & KARRIERE
SERVICE
im innovations-report
in Kooperation mit academics