ULOGA ELEKTROMAGNETNIH MIKRONESTABILNOSTI U (RE)FORMIRANJU KVAZIPARALELNIH UDARNIH TALASA U UBRZAVANJU ČESTICA U KOSMIČKOJ PLAZMI

eBiblioteka

 
 

ULOGA ELEKTROMAGNETNIH MIKRONESTABILNOSTI U (RE)FORMIRANJU KVAZIPARALELNIH UDARNIH TALASA U UBRZAVANJU ČESTICA U KOSMIČKOJ PLAZMI

Show simple item record

dc.contributor.advisor Arbutina, Bojan
dc.contributor.author Zeković, Vladimir
dc.date.accessioned 2021-01-14T09:03:35Z
dc.date.available 2021-01-14T09:03:35Z
dc.date.issued 2020
dc.identifier.uri http://hdl.handle.net/123456789/5094
dc.description.abstract In the disertation, by the linear plasma theory we show that resonant electromagnetic (EM)micro-instabilities are excited by the two colliding plasmas which are interpenetrating eachother with the super-Alfv ́enic velocity, in the direction quasi-parallel to the magnetic field.The expected Rankine-Hugoniot shock conditions, naturally arise as a consequence of a highlyresonant interaction of ions with the instability. By using kinetic simulations, we find herethat such resonant instabilities appear in the linear stage, and we show how these instabilitiestrigger the shock formation during the non-linear stage.By theoretical modeling, we show how a magnetosonic soliton forms and leads to the periodicshock reformation and initiation of the return current of ions, which drives the EM upstreaminstability. We find that ions are being pre-accelerated by the upstream and shock instabilities ina mechanism that is similar to the diffusive shock acceleration (DSA). By our EM test particlesimulation runs we show that at quasi-parallel shocks, EM instabilities highly contribute toelectron pre-acceleration, leading to the formation of a power-law electron spectra through theFermi-like mechanism.By very long kinetic simulation runs, in this disertation we find that ions and electronsenter DSA in a similar number which is further applied in a model of non-linear DSA. Withinthis model, we obtain the theoretical particle spectra and we find the electron-to-proton ratioat high energies for the different Mach numbers. We show that the spectra of quasi-thermalparticles at the shock can be represented by a non-equilibriumκ-distribution. We find thatthe level of modification decreases andκ-index increases behind the shock, implying that theparticle distribution tends to become a Maxwellian. en_US
dc.description.provenance Submitted by Slavisha Milisavljevic (slavisha) on 2021-01-14T09:03:35Z No. of bitstreams: 1 ZekovicVladimir.pdf: 56607908 bytes, checksum: 750546fb0824e3121d1cf7beb0364097 (MD5) en
dc.description.provenance Made available in DSpace on 2021-01-14T09:03:35Z (GMT). No. of bitstreams: 1 ZekovicVladimir.pdf: 56607908 bytes, checksum: 750546fb0824e3121d1cf7beb0364097 (MD5) Previous issue date: 2020 en
dc.language.iso sr en_US
dc.publisher Beograd en_US
dc.title ULOGA ELEKTROMAGNETNIH MIKRONESTABILNOSTI U (RE)FORMIRANJU KVAZIPARALELNIH UDARNIH TALASA U UBRZAVANJU ČESTICA U KOSMIČKOJ PLAZMI en_US
mf.author.birth-date 1982-07-12
mf.author.birth-place Beograd en_US
mf.author.birth-country Srbija en_US
mf.author.residence-state Srbija en_US
mf.author.citizenship Srpsko en_US
mf.author.nationality Srbin en_US
mf.subject.area Astronomy en_US
mf.subject.keywords quasi-parallel collisionless shocks, plasma micro-instabilities, particle accelera-tion, kinetic simulations en_US
mf.subject.subarea Astrophysics en_US
mf.contributor.committee Arbutina, Bojan
mf.contributor.committee Urošević, Dejan
mf.contributor.committee Spitkovsky, Anatoly
mf.university.faculty Mathematical faculty en_US
mf.document.pages 89 en_US
mf.document.location Belgrade en_US
mf.document.genealogy-project No en_US
mf.university Belgrade University en_US

Files in this item

Files Size Format View
ZekovicVladimir.pdf 56.60Mb PDF View/Open

This item appears in the following Collection(s)

Show simple item record