Non-ambipolar radio-frequency plasma electron source and systems and methods for generating electron beams
Abstract
An electron generating device extracts electrons, through an electron sheath, from plasma produced using RF fields. The electron sheath is located near a grounded ring at one end of a negatively biased conducting surface, which is normally a cylinder. Extracted electrons pass through the grounded ring in the presence of a steady state axial magnetic field. Sufficiently large magnetic fields and/or RF power into the plasma allow for helicon plasma generation. The ion loss area is sufficiently large compared to the electron loss area to allow for total non-ambipolar extraction of all electrons leaving the plasma. Voids in the negatively-biased conducting surface allow the time-varying magnetic fields provided by the antenna to inductively couple to the plasma within the conducting surface. The conducting surface acts as a Faraday shield, which reduces any time-varying electric fields from entering the conductive surface, i.e. blocks capacitive coupling between the antenna and the plasma.
- Inventors:
-
- Madison, WI
- Issue Date:
- Research Org.:
- Univ. of Wisconsin, Madison, WI (United States)
- Sponsoring Org.:
- USDOE
- OSTI Identifier:
- 973142
- Patent Number(s):
- 7498592
- Application Number:
- 11/427,273
- Assignee:
- Wisconsin Alumni Research Foundation (Madison, WI)
- Patent Classifications (CPCs):
-
F - MECHANICAL ENGINEERING F03 - MACHINES OR ENGINES FOR LIQUIDS F03H - PRODUCING A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
H - ELECTRICITY H01 - BASIC ELECTRIC ELEMENTS H01J - ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- DOE Contract Number:
- FG02-97ER54437
- Resource Type:
- Patent
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 47 OTHER INSTRUMENTATION
Citation Formats
Hershkowitz, Noah, Longmier, Benjamin, and Baalrud, Scott. Non-ambipolar radio-frequency plasma electron source and systems and methods for generating electron beams. United States: N. p., 2009.
Web.
Hershkowitz, Noah, Longmier, Benjamin, & Baalrud, Scott. Non-ambipolar radio-frequency plasma electron source and systems and methods for generating electron beams. United States.
Hershkowitz, Noah, Longmier, Benjamin, and Baalrud, Scott. Tue .
"Non-ambipolar radio-frequency plasma electron source and systems and methods for generating electron beams". United States. https://www.osti.gov/servlets/purl/973142.
@article{osti_973142,
title = {Non-ambipolar radio-frequency plasma electron source and systems and methods for generating electron beams},
author = {Hershkowitz, Noah and Longmier, Benjamin and Baalrud, Scott},
abstractNote = {An electron generating device extracts electrons, through an electron sheath, from plasma produced using RF fields. The electron sheath is located near a grounded ring at one end of a negatively biased conducting surface, which is normally a cylinder. Extracted electrons pass through the grounded ring in the presence of a steady state axial magnetic field. Sufficiently large magnetic fields and/or RF power into the plasma allow for helicon plasma generation. The ion loss area is sufficiently large compared to the electron loss area to allow for total non-ambipolar extraction of all electrons leaving the plasma. Voids in the negatively-biased conducting surface allow the time-varying magnetic fields provided by the antenna to inductively couple to the plasma within the conducting surface. The conducting surface acts as a Faraday shield, which reduces any time-varying electric fields from entering the conductive surface, i.e. blocks capacitive coupling between the antenna and the plasma.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Mar 03 00:00:00 EST 2009},
month = {Tue Mar 03 00:00:00 EST 2009}
}
Works referenced in this record:
Neutral pumping in a helicon discharge
journal, August 1998
- Gilland, J.; Breun, R.; Hershkowitz, N.
- Plasma Sources Science and Technology, Vol. 7, Issue 3
Helicons-the early years
journal, January 1997
- Boswell, R. W.; Chen, F. F.
- IEEE Transactions on Plasma Science, Vol. 25, Issue 6
Steady‐state ion pumping of a potential dip near an electron collecting anode
journal, August 1986
- Forest, Cary; Hershkowitz, Noah
- Journal of Applied Physics, Vol. 60, Issue 4
Non-ambipolr electron extraction from a weakly magnetized RF plasma
conference, January 2006
- Hershkowitz, N.; Longmier, B. W.
- The 33rd IEEE International Conference on Plasma Science, 2006. ICOPS 2006. IEEE Conference Record - Abstracts.
Sheaths: More complicated than you think
journal, May 2005
- Hershkowitz, Noah
- Physics of Plasmas, Vol. 12, Issue 5
"Electrodeless" Plasma Cathode for Neutralization of Ion Thrusters
conference, June 2012
- Longmier, Benjamin; Hershkowitz, Noah
- 41st AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit
Helicons-the past decade
journal, January 1997
- Chen, F. F.; Boswell, R. W.
- IEEE Transactions on Plasma Science, Vol. 25, Issue 6