Parametric investigation of orifice aspect-ratio on low current hollow cathode power consumption

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76725/1/AIAA-1998-3345-942.pd

A Hall probe diagnostic for low density plasma accelerators

A Hall probe diagnostic was developed for use with plasma thrusters. The Hall generators were mounted at the end of a stainless steel tube heat exchanger. Ceramic cement and a Pyrex tube were used as radiation and particle flux shields, respectively. A thermocouple was used to monitor the temperature of the Hall generator. The low voltage output from the probe was amplified within one meter of the transducer to minimize the effect of noise pick up. A National Institute of Standards and Technology traceable Gaussmeter provided an absolute reference for calibration, and relative calibrations were performed both in a strong electric field and in situ during thruster operation to approximate the conditions in the discharge. The overall accuracy of the diagnostic was ±6 G.±6G. The probes were tested with a Hall-effect thruster, and provided sufficiently accurate data to estimate the magnitude of the closed-drift electron current. © 1998 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69868/2/RSINAK-69-6-2546-1.pd

Evaluation of externally heated pulsed MPD thruster cathodes

Recent interest in solar electric orbit transfer vehicles (SEOTV's) has prompted a reevaluation of pulsed magnetoplasmadynamic (MPD) thruster systems due to their ease of power scaling and reduced test facility requirements. In this work the use of externally heated cathodes was examined in order to extend the lifetime of these thrusters to the 1000 to 3000 hours required for SEOTV missions. A pulsed MPD thruster test facility was assembled, including a pulse-forming network (PFN), ignitor supply and propellant feed system. Results of cold cathode tests used to validate the facility, PFN, and propellant feed system design are presented, as well as a preliminary evaluation of externally heated impregnated tungsten cathodes. The cold cathode thruster was operated on both argon and nitrogen propellants at peak discharge power levels up to 300 kW. The results confirmed proper operation of the pulsed thruster test facility, and indicated that large amounts of gas were evolved from the BaO-CaO-Al2O3 cathodes during activation. Comparison of the expected space charge limited current with the measured vacuum current when using the heated cathode indicate that either that a large temperature difference existed between the heater and the cathode or that the surface work function was higher than expected

Low power pulsed MPD thruster system analysis and applications

Pulsed magnetoplasmadynamic (MPD) thruster systems were analyzed for application to solar-electric orbit transfer vehicles at power levels ranging from 10 to 40 kW. Potential system level benefits of pulsed propulsion technology include ease of power scaling without thruster performance changes, improved transportability from low power flight experiments to operational systems, and reduced ground qualification costs. Required pulsed propulsion system components include a pulsed applied-field MPD thruster, a pulse-forming network, a charge control unit, a cathode heater supply, and high speed valves. Mass estimates were obtained for each propulsion subsystem and spacecraft component using off-the-shelf technology whenever possible. Results indicate that for payloads of 1000 and 2000 kg pulsed MPD thrusters can reduce launch mass by between 1000 and 2500 kg over those achievable with hydrogen arcjets, which can be used to reduce launch vehicle class and the associated launch cost. While the achievable mass savings depends on the trip time allowed for the mission, cases are shown in which the launch vehicle required for a mission is decreased from an Atlas IIAS to an Atlas I or Delta 7920

The Status of Laser Diagnostics Supporting Ion Thruster Development at NASA GRC

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76321/1/AIAA-2002-3960-677.pd

Sensitivity of hollow cathode performance to design and operating parameters

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76435/1/AIAA-1999-2576-299.pd

Very near-field plume investigation of the D55

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76343/1/AIAA-1997-3062-753.pd

Low-current hollow cathode evaluation

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76856/1/AIAA-1999-2575-648.pd

IMECE2002-39444 ION ENGINE AND HALL THRUSTER DEVELOPMENT AT THE NASA GLENN RESEARCH CENTER

ABSTRACT NASA's Glenn Research Center has been selected to lead development of NASA's Evolutionary Xenon Thruster (NEXT) system. The central feature of the NEXT system is an electric propulsion thruster (EPT) that inherits the knowledge gained through the NSTAR thruster that successfully propelled Deep Space 1 to asteroid Braille and comet Borrelly, while significantly increasing the thruster power level and making improvements in performance parameters associated with NSTAR. The EPT concept under development has a 40 cm beam diameter, twice the effective area of the Deep-Space 1 thruster, while maintaining a relatively-small volume. It incorporates mechanical features and operating conditions to maximize the design heritage established by the flight NSTAR 30 cm engine, while incorporating new technology where warranted to extend the power and throughput capability. The NASA Hall thruster program currently supports a number of tasks related to high power thruster development for a number of customers including the Energetics Program (formerly called the Space-based Program), the Space Solar Power Program, and the In-space Propulsion Program. In program year 2002, two tasks were central to the NASA Hall thruster program: 1.) the development of a laboratory Hall thruster capable of providing high thrust at high power; 2.) investigations into operation of Hall thrusters at high specific impulse. In addition to these two primary thruster development activities, there are a number of other on-going activities supported by the NASA Hall thruster program. These additional activities are related to issues such as thruster lifetime and spacecraft integration. INTRODUCTION The success of the NASA Solar Electric Propulsion Technology Applications Readiness (NSTAR) program io

The D-100 performance and plume characterization on krypton

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76487/1/AIAA-1996-2969-208.pd