We present the initial results from a cavity ring-down sensor for measuring the density of sputtered boron atoms originating from the discharge channel of a 6-kW Hall thruster. The sensor traps 250 nm light in a high-finesse cavity to greatly increase its sensitivity to boron atoms. Measurements were obtained with the thruster operating at seven conditions spanning discharge voltages from 150 t...

Various methods for accurately determining ion species’ current fractions using E B probes in Hall thruster plumes are investigated. The effects of peak broadening and charge exchange on the calculated values of current fractions are quantified in order to determine the importance of accounting for them in the analysis. It is shown that both peak broadening and charge exchange have a significan...

Abstract The Half-Rotating impeller thruster(HRIT) based on the Mechanism is a new type of thruster. Its motion principle different from fixed ordinary In order to obtain better aerodynamic force in working, it necessary explore HRIT structural parameters. influence radius rotating arm, width blade calculated and analyzed detail by numerical calculation method. results show that arm main factor...

A neutral background pressure map of the Large Vacuum Test Facility (LVTF) at the University of Michigan is presented. The LVTF was mapped at hot anode (i.e., discharge on) flow rates of 5.25 and 10.46 mg/s, corresponding to P5 Hall thruster operating conditions of 1.5 and 3.0 kW. The chamber pressure was mapped at nominal xenon pumping speeds of 140,000 and 240,000 l/s, corresponding to base p...

* Presented as Paper IEPC-01-39 at the 27 International Electric Propulsion Conference, Pasadena, CA, 15-19 October 2001. † Copyright © 2001 by Stanford University. Published by the Electric Rocket Propulsion Society with permission. A preliminary assessment of the sputter resistance of polycrystalline diamond plates against xenon ion bombardment is reported, and first studies of integrating di...

A new dual-fluid concept was studied that could eventually find application for cold-gas propulsion for small space satellites or other constant flow applications. In basic form, the concept uses two different refrigerant working fluids, each having a different saturation vapor pressure. The higher vapor pressure refrigerant remains in the saturation phase and is used to pressurize the lower sa...

Title of Document: DEV DEVELOPMENT AND TEST OF A PERMANENT MAGNET HELICON THRUSTER Michael Frank DeMaio, Jr. M.S. 2010 Directed By: Assistant Professor Raymond Sedwick, Department of Aerospace Engineering This thesis describes the development of a test facility equipped with Langmuir probe and Retarding Potential Analyzer diagnostics for helicon thruster research. A helicon thruster using perma...

We present an algorithm for estimating thruster configurations of underwater vehicles with reconfigurable thrusters. The algorithm estimates each thruster’s effect on the vehicle’s attitude and position. The estimated parameters are used to maintain the robot’s attitude and position. The algorithm operates by measuring impulse response of individual thrusters and thruster combinations. Statisti...

We study the density-density correlation function of the dense random het-eropolymer solutions. We show that a phase transition is possible due to the het-erogeneity of polymers. We also show that the critical behavior of the system is described by the O(N) model at N = 0.

Vacuum ultraviolet emission (137.9 nm) of boron neutrals sputtered from a 200 W xenon Hall thruster boron nitride insulator is evaluated as a diagnostic for real time evaluation of thruster insulator erosion. Three Hall thruster plasma control variables are examined; ion energy (discharge potential), ion flux (propellant flow), and plasma conductivity (magnetic field strength). The boron emissi...