Electron velocity distribution instability in magnetized plasma wakes and artificial electron mass
The wake behind a large object (such as the moon) moving rapidly through a plasma (such as the solar wind) contains a region of depleted density, into which the plasma expands along the magnetic field, transverse to the flow. It is shown here that (in addition to any ion instability) a bump-on-tail...
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| Format: | Article |
| Language: | en_US |
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American Geophysical Union (AGU)
2014
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| Online Access: | http://hdl.handle.net/1721.1/84057 |
| _version_ | 1811091392374505472 |
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| author | Hutchinson, Ian Horner |
| author2 | Massachusetts Institute of Technology. Department of Nuclear Science and Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Nuclear Science and Engineering Hutchinson, Ian Horner |
| author_sort | Hutchinson, Ian Horner |
| collection | MIT |
| description | The wake behind a large object (such as the moon) moving rapidly through a plasma (such as the solar wind) contains a region of depleted density, into which the plasma expands along the magnetic field, transverse to the flow. It is shown here that (in addition to any ion instability) a bump-on-tail which is unstable appears on the electrons' parallel velocity distribution function because of the convective non-conservation of parallel energy (drift-energization). It arises regardless of any non-thermal features on the external electron velocity distribution. The detailed electron distribution function throughout the wake is calculated by integration along orbits; and the substantial energy level of resulting electron plasma (Langmuir) turbulence is evaluated quasi-linearly. It peaks near the wake axis. If the mass of the electrons is artificially enhanced, for example in order to make numerical simulation feasible, then much more unstable electron distributions arise; but these are caused by the unphysical mass ratio. |
| first_indexed | 2024-09-23T15:01:41Z |
| format | Article |
| id | mit-1721.1/84057 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T15:01:41Z |
| publishDate | 2014 |
| publisher | American Geophysical Union (AGU) |
| record_format | dspace |
| spelling | mit-1721.1/840572023-02-26T02:14:54Z Electron velocity distribution instability in magnetized plasma wakes and artificial electron mass Hutchinson, Ian Horner Massachusetts Institute of Technology. Department of Nuclear Science and Engineering Massachusetts Institute of Technology. Plasma Science and Fusion Center Hutchinson, Ian Hutchinson, Ian H. The wake behind a large object (such as the moon) moving rapidly through a plasma (such as the solar wind) contains a region of depleted density, into which the plasma expands along the magnetic field, transverse to the flow. It is shown here that (in addition to any ion instability) a bump-on-tail which is unstable appears on the electrons' parallel velocity distribution function because of the convective non-conservation of parallel energy (drift-energization). It arises regardless of any non-thermal features on the external electron velocity distribution. The detailed electron distribution function throughout the wake is calculated by integration along orbits; and the substantial energy level of resulting electron plasma (Langmuir) turbulence is evaluated quasi-linearly. It peaks near the wake axis. If the mass of the electrons is artificially enhanced, for example in order to make numerical simulation feasible, then much more unstable electron distributions arise; but these are caused by the unphysical mass ratio. National Science Foundation (U.S.) United States. Dept. of Energy (Grant DE-FG02-06ER54982) 2014-01-17T15:02:49Z 2014-01-17T15:02:49Z 2012-03 2011-12 Article http://purl.org/eprint/type/JournalArticle 0148-0227 2156-2202 http://hdl.handle.net/1721.1/84057 Hutchinson, I. H. “Electron velocity distribution instability in magnetized plasma wakes and artificial electron mass.” Journal of Geophysical Research 117, no. A3 (March 7, 2012). en_US http://dx.doi.org/10.1029/2011ja017119 Journal of Geophysical Research Creative Commons Attribution-Noncommercial-Share Alike 3.0 http://creativecommons.org/licenses/by-nc-sa/3.0/ application/pdf American Geophysical Union (AGU) Prof. Hutchinson via Chris Sherratt |
| spellingShingle | Hutchinson, Ian Horner Electron velocity distribution instability in magnetized plasma wakes and artificial electron mass |
| title | Electron velocity distribution instability in magnetized plasma wakes and artificial electron mass |
| title_full | Electron velocity distribution instability in magnetized plasma wakes and artificial electron mass |
| title_fullStr | Electron velocity distribution instability in magnetized plasma wakes and artificial electron mass |
| title_full_unstemmed | Electron velocity distribution instability in magnetized plasma wakes and artificial electron mass |
| title_short | Electron velocity distribution instability in magnetized plasma wakes and artificial electron mass |
| title_sort | electron velocity distribution instability in magnetized plasma wakes and artificial electron mass |
| url | http://hdl.handle.net/1721.1/84057 |
| work_keys_str_mv | AT hutchinsonianhorner electronvelocitydistributioninstabilityinmagnetizedplasmawakesandartificialelectronmass |