8-12 July 2013
Africa/Johannesburg timezone
<a href="http://events.saip.org.za/internalPage.py?pageId=13&confId=32"><font color=#ff0000>SAIP2013 PROCEEDINGS AVAILABLE</font></a>

Electrostatic wave Instabilities driven by counter-streaming electron beams in space plasmas

10 Jul 2013, 15:40
20m
Oral Presentation Track D2 - Space Science Space Science

Speaker

Mr Lifa Mbuli (South African National Space Agency (SANSA) Space Science, P.O Box 32, Hermanus 7200, South Africa / Department of Physics, University of the Western Cape, Robert Sobukwe Road, Bellville 7535, South Africa)

Apply to be<br> considered for a student <br> &nbsp; award (Yes / No)?

Yes

Level for award<br>&nbsp;(Hons, MSc, <br> &nbsp; PhD)?

MSc

Abstract content <br> &nbsp; (Max 300 words)

Broadband electrostatic noise(BEN) observed in satellite data is found to be associated with field-aligned electron or ion beams in different regions of the magnetosphere such as the plasma sheet boundary layer(PSBL), bow shock and auroral kilometric radiation(AKR) regions. We consider a four-component plasma composed of drifting (parallel to ambient magnetic field) warm electrons and drifting (anti-parallel to ambient magnetic field) cool electrons and background hot electrons and ions in an attempt to further understand the excitation mechanisms for BEN. Using kinetic theory, electrostatic instabilities such as ion-acoustic, electron-acoustic and counter-streaming beam-resonant instabilities are found to be supported. The dependence of the instability growth rates and real frequencies on various plasma parameters such as cool electron beam speed, number density, temperature and temperature anisotropy, as well as the magnetic field strength are examined. It is found that cool electron beam number density and speed determines which instability can be excited. Using plasma parameters which are closely aligned with the measurements
made by the Cluster satellites in the PSBL regions we find that the electron-acoustic and ion-acoustic
instabilities could account for the generation of BEN in this region.

Main supervisor (name and email)<br>and his / her institution

Ramesh Bharuthram, rbharuthram@uwc.ac.za, University of the Western Cape

Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?

Yes

Primary author

Mr Lifa Mbuli (South African National Space Agency (SANSA) Space Science, P.O Box 32, Hermanus 7200, South Africa / Department of Physics, University of the Western Cape, Robert Sobukwe Road, Bellville 7535, South Africa)

Co-authors

Prof. Ramesh Bharuthram (University of the Western Cape, Office of the Deputy Vice-Chancellor (Academic), Robert Sobukwe Road, Bellville 7535, South Africa) Dr Shimul Maharaj (South African National Space Agency (SANSA) Space Science, P.O Box 32, Hermanus 7200, South Africa)

Presentation Materials

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