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 It's filamentary: How galaxies evolve in the cosmic web
21.11.2014 | University of California - Riverside

nachricht How to estimate the magnetic field of an exoplanet?
21.11.2014 | Lomonosov Moscow State University

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Anzeige

Anzeige

IHR
JOB & KARRIERE
SERVICE
im innovations-report
in Kooperation mit academics
Veranstaltungen

Think CROSS – Change MEDIA 2015

21.11.2014 | Veranstaltungen

Deutsche Börse und KfW veranstalten Deutsches Eigenkapitalforum 2014

20.11.2014 | Veranstaltungen

e:Med - Systemmediziner treffen sich in Heidelberg

20.11.2014 | Veranstaltungen

 
B2B-VideoLinks
Weitere VideoLinks >>>
Aktuelle Beiträge

Umrichter mit höherer Leistungsdichte bei platzsparender Baugrösse

21.11.2014 | Maschinenbau

Siemens bietet Simotics-Standardmotoren in höchster Effizienzklasse IE4

21.11.2014 | Maschinenbau

Siemens erhält Auftrag für H-Klasse-Turbinentechnologie aus Ohio (USA)

21.11.2014 | Unternehmensmeldung