The electrodeless Lorentz force (ELF) thruster experimental facility

Abstract

An innovative facility for testing high-power, pulsed plasmoid thrusters has been constructed to develop the electrodeless Lorentz force (ELF) thruster concept. It is equipped with a suite of diagnostics optimized to study the physical processes taking place within ELF and evaluate its propulsive utility including magnetic field, neutral gas, and plasma flux diagnostics, a method to determine energy flow into the plasma from the pulsed power systems, and a new type of ballistic pendulum, which enables thrust to be measured without the need for installing the entire propulsion system on a thrust stand. Variable magnetic fields allow controlled studies of plume expansion in a small-scale experiment and dielectric chamber walls reduce electromagnetic influences on plasma behavior and thruster operation. The unique capabilities of this facility enable novel concept development to take place at greatly reduced cost and increased accessibility compared to testing at large user-facilities.

Steady Operation of an FRC Thruster on Martian Atmosphere and Liquid Water Propellants

“…And finally, external magnetic flux loops are used to characterize the total plasma trapped flux as well as flux leakage through the external flux conservers. These diagnostics are the traditional FRC thruster diagnostics and are well documented in [3] and [10].…”

“…Internal double Langmuir probes resolve transient plasma density at less than 1 microsecond resolution are implemented in the standard "hook" formation [10] .These probes are asymmetric double Lanmguir probes with an ion saturation collection area of 50 mm 2 and are swept from -36 to +36 volts. They are fed from the outside of the chamber, shown in Figure 4.…”

State-of-the-Art and Advancement Paths for Inductive Pulsed Plasma Thrusters

“…There are multiple mechanisms that have been proposed to date by which RMF-FRCs may be axially accelerated to generate thrust. These include a Lorentz body force that results from interaction with the applied field [42], a self-field-derived Lorentz body force [43], and thermal-to-kinetic energy conversion [44]. We proceed with a brief discussion of each mechanism.…”

Plasma-gun-assisted field-reversed configuration formation in a conical θ-pinch

“…Deuterium gas is introduced through a polyethylene manifold to prevent image currents, then through 6 fast pulse valves (2 guns per valve) that are overdriven to increase pulse speed. 39 Each gun is driven by an optically triggered, SCR-switched and crowbarred, 1.1 mF (550 J per gun and 6.6 kJ for the 12 gun array) electrolytic capacitor bank. Although the triggering system is capable of firing the guns independently, all guns were triggered simultaneously for this study.…”