Lorentz Force Accelerator with an Open-ended Lithium Heat Pipe

Title:

Authors:

Edgar Choueiri, Vincent Chiravalle, George E. Miller and Robert G. Jahn ( EPPDyL, Princeton University)

William Anderson and Joe Bland (Thermacore Inc.)

Document type:

AIAA paper: AIAA-96-2737 Presented at the 32nd AIAA Joint Propulsion Conference, Lake Buena Vista, FL, July 1-3, 1996.

Access:

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Abstract:

A steady-state coaxial Lorentz force accelerator (LFA), where lithium propellant is supplied by an open-ended heat pipe, was designed and built. The open-ended heat pipe provides a novel alternative to the complex propellant feeding systems previously used with lithium-fed thrusters. The closed end of the heat pipe acts as a reservoir containing a liquid lithium pool, and a wick. The main part of the pipe is embedded in a furnace (1200 deg. C) which vaporizes the lithium off the wick. The lithium vapor then travels to the open end which is also the cathode of the LFA supplying the propellant for the plasma thruster. The actively heated cathode is a hybrid hollow-multi-channel cathode consisting of 48 longitudinal channels embedded in a porous tungsten insert. The design promises a substantial decrease in the erosion rate of the cathode which is the lifetime limiting component in such thrusters. This paper describes the design and fabrication of the thruster as well as the mass flow rate calibration procedure which relies on careful water calorimetry.

Additional Keywords: MPD thrusters, alkali metals, electric propulsion