Measurement of cross-section geometry effects on electron collection to long probes in mesosonic flowing plasmas

Éric Choinière, Brian E. Gilchrist, Sven G. Bilen, Keith R. Fuhrhop

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

This paper presents the analysis and comparison of measured electron current collection to cylindrical, solid tape, and slotted tape electrodynamic-tether samples in a mesosonic flowing plasma. A Hall thruster was used to simulate a flowing unmagnetized space plasma in a large 6m× 9m vacuum chamber. Guarded tether samples were designed to mitigate end effects. Plasma parameters were determined based on the ion saturation and electron retardation regimes of a Langmuir probe's current characteristics. Solid tape samples with effective widths spanning from 4.9 to 41.9 Debye lengths, and slotted tapes with line spacings spanning from 1.4 to 13.2 Debye lengths were tested. Several conclusions can be drawn from the analysis of the results: 1) The plasma flow leads to current enhancements over that predicted by the orbital-motion-limited theory; 2) the electron collection efficiency of solid tapes (on a per area basis) decreases as the width of the tape is increased; 3) beyond a threshold bias close to the beam energy, solid and slotted tapes both collect more current when oriented transverse to the flow; 4) equivalent width slotted tapes are more efficient electron collectors than solid tapes on a per area basis; 5) our data suggests the electron collection efficiency of slotted tapes decreases with increasing line spacing until a possible minimum efficiency is attained, beyond which it is expected to start increasing again. The minimum was attained in the case of the samples oriented transverse to the flow, but not in the case of the samples aligned with the flow, for which the critical spacing is likely higher due to an increased sheath interaction radius of each line caused by the elongation of the sheath associated with plasma flow.

Original languageEnglish (US)
Title of host publication39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit
StatePublished - Dec 1 2003
Event39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit 2003 - Huntsville, AL, United States
Duration: Jul 20 2003Jul 23 2003

Publication series

Name39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit

Other

Other39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit 2003
CountryUnited States
CityHuntsville, AL
Period7/20/037/23/03

Fingerprint

Tapes
Plasmas
Geometry
Electrons
Plasma flow
Hall thrusters
Plasma sheaths
Langmuir probes
Electrodynamics
Elongation
Vacuum
Ions

All Science Journal Classification (ASJC) codes

  • Aerospace Engineering
  • Control and Systems Engineering
  • Electrical and Electronic Engineering

Cite this

Choinière, É., Gilchrist, B. E., Bilen, S. G., & Fuhrhop, K. R. (2003). Measurement of cross-section geometry effects on electron collection to long probes in mesosonic flowing plasmas. In 39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit (39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit).
Choinière, Éric ; Gilchrist, Brian E. ; Bilen, Sven G. ; Fuhrhop, Keith R. / Measurement of cross-section geometry effects on electron collection to long probes in mesosonic flowing plasmas. 39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit. 2003. (39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit).
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abstract = "This paper presents the analysis and comparison of measured electron current collection to cylindrical, solid tape, and slotted tape electrodynamic-tether samples in a mesosonic flowing plasma. A Hall thruster was used to simulate a flowing unmagnetized space plasma in a large 6m× 9m vacuum chamber. Guarded tether samples were designed to mitigate end effects. Plasma parameters were determined based on the ion saturation and electron retardation regimes of a Langmuir probe's current characteristics. Solid tape samples with effective widths spanning from 4.9 to 41.9 Debye lengths, and slotted tapes with line spacings spanning from 1.4 to 13.2 Debye lengths were tested. Several conclusions can be drawn from the analysis of the results: 1) The plasma flow leads to current enhancements over that predicted by the orbital-motion-limited theory; 2) the electron collection efficiency of solid tapes (on a per area basis) decreases as the width of the tape is increased; 3) beyond a threshold bias close to the beam energy, solid and slotted tapes both collect more current when oriented transverse to the flow; 4) equivalent width slotted tapes are more efficient electron collectors than solid tapes on a per area basis; 5) our data suggests the electron collection efficiency of slotted tapes decreases with increasing line spacing until a possible minimum efficiency is attained, beyond which it is expected to start increasing again. The minimum was attained in the case of the samples oriented transverse to the flow, but not in the case of the samples aligned with the flow, for which the critical spacing is likely higher due to an increased sheath interaction radius of each line caused by the elongation of the sheath associated with plasma flow.",
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Choinière, É, Gilchrist, BE, Bilen, SG & Fuhrhop, KR 2003, Measurement of cross-section geometry effects on electron collection to long probes in mesosonic flowing plasmas. in 39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit. 39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, 39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit 2003, Huntsville, AL, United States, 7/20/03.

Measurement of cross-section geometry effects on electron collection to long probes in mesosonic flowing plasmas. / Choinière, Éric; Gilchrist, Brian E.; Bilen, Sven G.; Fuhrhop, Keith R.

39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit. 2003. (39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

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T1 - Measurement of cross-section geometry effects on electron collection to long probes in mesosonic flowing plasmas

AU - Choinière, Éric

AU - Gilchrist, Brian E.

AU - Bilen, Sven G.

AU - Fuhrhop, Keith R.

PY - 2003/12/1

Y1 - 2003/12/1

N2 - This paper presents the analysis and comparison of measured electron current collection to cylindrical, solid tape, and slotted tape electrodynamic-tether samples in a mesosonic flowing plasma. A Hall thruster was used to simulate a flowing unmagnetized space plasma in a large 6m× 9m vacuum chamber. Guarded tether samples were designed to mitigate end effects. Plasma parameters were determined based on the ion saturation and electron retardation regimes of a Langmuir probe's current characteristics. Solid tape samples with effective widths spanning from 4.9 to 41.9 Debye lengths, and slotted tapes with line spacings spanning from 1.4 to 13.2 Debye lengths were tested. Several conclusions can be drawn from the analysis of the results: 1) The plasma flow leads to current enhancements over that predicted by the orbital-motion-limited theory; 2) the electron collection efficiency of solid tapes (on a per area basis) decreases as the width of the tape is increased; 3) beyond a threshold bias close to the beam energy, solid and slotted tapes both collect more current when oriented transverse to the flow; 4) equivalent width slotted tapes are more efficient electron collectors than solid tapes on a per area basis; 5) our data suggests the electron collection efficiency of slotted tapes decreases with increasing line spacing until a possible minimum efficiency is attained, beyond which it is expected to start increasing again. The minimum was attained in the case of the samples oriented transverse to the flow, but not in the case of the samples aligned with the flow, for which the critical spacing is likely higher due to an increased sheath interaction radius of each line caused by the elongation of the sheath associated with plasma flow.

AB - This paper presents the analysis and comparison of measured electron current collection to cylindrical, solid tape, and slotted tape electrodynamic-tether samples in a mesosonic flowing plasma. A Hall thruster was used to simulate a flowing unmagnetized space plasma in a large 6m× 9m vacuum chamber. Guarded tether samples were designed to mitigate end effects. Plasma parameters were determined based on the ion saturation and electron retardation regimes of a Langmuir probe's current characteristics. Solid tape samples with effective widths spanning from 4.9 to 41.9 Debye lengths, and slotted tapes with line spacings spanning from 1.4 to 13.2 Debye lengths were tested. Several conclusions can be drawn from the analysis of the results: 1) The plasma flow leads to current enhancements over that predicted by the orbital-motion-limited theory; 2) the electron collection efficiency of solid tapes (on a per area basis) decreases as the width of the tape is increased; 3) beyond a threshold bias close to the beam energy, solid and slotted tapes both collect more current when oriented transverse to the flow; 4) equivalent width slotted tapes are more efficient electron collectors than solid tapes on a per area basis; 5) our data suggests the electron collection efficiency of slotted tapes decreases with increasing line spacing until a possible minimum efficiency is attained, beyond which it is expected to start increasing again. The minimum was attained in the case of the samples oriented transverse to the flow, but not in the case of the samples aligned with the flow, for which the critical spacing is likely higher due to an increased sheath interaction radius of each line caused by the elongation of the sheath associated with plasma flow.

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M3 - Conference contribution

SN - 9781624100987

T3 - 39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit

BT - 39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit

ER -

Choinière É, Gilchrist BE, Bilen SG, Fuhrhop KR. Measurement of cross-section geometry effects on electron collection to long probes in mesosonic flowing plasmas. In 39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit. 2003. (39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit).