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Experimental Evaluation of a Standal...

Ku, Emily X.,

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Experimental Evaluation of a Standalone Hollow Cathode Apparatus With a Magnetic Field /

Record Type:	Electronic resources : Monograph/item
Title/Author:	Experimental Evaluation of a Standalone Hollow Cathode Apparatus With a Magnetic Field // Emily X Ku.
Author:	Ku, Emily X.,
Description:	1 electronic resource (46 pages)
Notes:	Source: Masters Abstracts International, Volume: 86-06.
Contained By:	Masters Abstracts International86-06.
Subject:	Plasma physics. -
Online resource:	https://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=31632889
ISBN:	9798346869313

Experimental Evaluation of a Standalone Hollow Cathode Apparatus With a Magnetic Field /
Ku, Emily X.,

Experimental Evaluation of a Standalone Hollow Cathode Apparatus With a Magnetic Field /Emily X Ku. - 1 electronic resource (46 pages)

Source: Masters Abstracts International, Volume: 86-06.

Testing hollow cathode assemblies independently from their use in Hall or gridded ion thrusters offers advantages such as reduced test facility size, lower power requirements, and improved diagnostic access. Standalone tests can reveal important cathode characteristics like ignition time, keeper ignition voltage, tip temperature, and current capability. Replicating the plasma phenomena that occur when a cathode operates within a thruster is challenging but essential, as these phenomena can generate energetic ions that erode cathode and keeper surfaces, limiting thruster lifespan. The primary challenge is to accurately emulate thruster conditions in standalone tests and verify this emulation through comparison with cathode-thruster operations. This thesis presents data on a standalone hollow cathode operated with magnetic fields that emulate those in electric propulsion devices, testing it both without an applied magnetic field and with permanent and solenoidal magnetic fields. Measurements of keeper, anode, and cathode-to-ground voltages were conducted over a range of anode currents and flow rates. At certain conditions, the plasma discharge transitioned to a less stable mode known as plume mode, with higher flow rates shifting this transition to higher anode currents. Introducing a magnetic field decreased the anode current at which this voltage shift occurred. Important findings in this work include: (1) Repeat tests with no magnetic field show that the transition behavior was different from one test to another, indicating that transition behavior may be affected by minute changes in cathode apparatus, or there are significant uncertainties associated with the transition and (2) Significant hysteresis in plume mode transition was observed when increasing and then decreasing anode current. These two findings along with the deleterious effects of the magnetic field have important implications on cathodes operating with Hall thrusters, which often exhibit large, rapid oscillations in discharge current.

English

ISBN: 9798346869313Subjects--Topical Terms:

3175417
Plasma physics.
Subjects--Index Terms:

Cathode

Experimental Evaluation of a Standalone Hollow Cathode Apparatus With a Magnetic Field /
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245 1 0 $a Experimental Evaluation of a Standalone Hollow Cathode Apparatus With a Magnetic Field / $c Emily X Ku.
264 1 $a Ann Arbor : $b ProQuest Dissertations & Theses, $c 2024
300 $a 1 electronic resource (46 pages)
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500 $a Source: Masters Abstracts International, Volume: 86-06.
500 $a Advisors: Williams, John Committee members: Dumitrache, Ciprian; Thornton, Christopher.
502 $b M.S. $c Colorado State University $d 2024.
520 $a Testing hollow cathode assemblies independently from their use in Hall or gridded ion thrusters offers advantages such as reduced test facility size, lower power requirements, and improved diagnostic access. Standalone tests can reveal important cathode characteristics like ignition time, keeper ignition voltage, tip temperature, and current capability. Replicating the plasma phenomena that occur when a cathode operates within a thruster is challenging but essential, as these phenomena can generate energetic ions that erode cathode and keeper surfaces, limiting thruster lifespan. The primary challenge is to accurately emulate thruster conditions in standalone tests and verify this emulation through comparison with cathode-thruster operations. This thesis presents data on a standalone hollow cathode operated with magnetic fields that emulate those in electric propulsion devices, testing it both without an applied magnetic field and with permanent and solenoidal magnetic fields. Measurements of keeper, anode, and cathode-to-ground voltages were conducted over a range of anode currents and flow rates. At certain conditions, the plasma discharge transitioned to a less stable mode known as plume mode, with higher flow rates shifting this transition to higher anode currents. Introducing a magnetic field decreased the anode current at which this voltage shift occurred. Important findings in this work include: (1) Repeat tests with no magnetic field show that the transition behavior was different from one test to another, indicating that transition behavior may be affected by minute changes in cathode apparatus, or there are significant uncertainties associated with the transition and (2) Significant hysteresis in plume mode transition was observed when increasing and then decreasing anode current. These two findings along with the deleterious effects of the magnetic field have important implications on cathodes operating with Hall thrusters, which often exhibit large, rapid oscillations in discharge current.
546 $a English
590 $a School code: 0053
650 4 $a Plasma physics. $3 3175417
650 4 $a Aerospace engineering. $3 1002622
650 4 $a Electromagnetics. $3 3173223
650 4 $a Mechanical engineering. $3 649730
653 $a Cathode
653 $a Electric propulsion
653 $a Hall thruster
653 $a Hollow cathode
653 $a Magnetic field
653 $a Plasma discharge
690 $a 0759
690 $a 0538
690 $a 0548
690 $a 0607
710 2 $a Colorado State University. $b Mechanical Engineering. $e degree granting institution. $3 3821970
720 1 $a Williams, John $e degree supervisor.
773 0 $t Masters Abstracts International $g 86-06.
790 $a 0053
791 $a M.S.
792 $a 2024
856 4 0 $u https://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=31632889