35320
2013
2013
eng
1535
1541
7
9
31
article
Copernicus
Göttingen
1
--
--
--
Magnetic field generation in a jet-sheath plasma via the kinetic Kelvin-Helmholtz instability
We have investigated the generation of magnetic fields associated with velocity shear between an unmagnetized relativistic jet and an unmagnetized sheath plasma. We have examined the strong magnetic fields generated by kinetic shear (Kelvin-Helmholtz) instabilities. Compared to the previous studies using counter-streaming performed by Alves et al. (2012), the structure of the kinetic Kelvin-Helmholtz instability (KKHI) of our jet-sheath configuration is slightly different, even for the global evolution of the strong transverse magnetic field. In our simulations the major components of growing modes are the electric field E-z, perpendicular to the flow boundary, and the magnetic field B-y, transverse to the flow direction. After the B-y component is excited, an induced electric field E-x, parallel to the flow direction, becomes significant. However, other field components remain small. We find that the structure and growth rate of KKHI with mass ratios m(i)/m(e) = 1836 and m(i)/m(e) = 20 are similar. In our simulations in the nonlinear stage is not as clear as in counter-streaming cases. The growth rate for a mildly-relativistic jet case (gamma(j) = 1.5) is larger than for a relativistic jet case (gamma(j) = 15).
Annales geophysicae
10.5194/angeo-31-1535-2013
0992-7689
wos:2011-2013
WOS:000325345800005
Nishikawa, KI (reprint author), Univ Alabama, Ctr Space Plasma & Aeron Res, 320 Sparkman Dr,ZP12, Huntsville, AL 35805 USA., ken-ichi.nishikawa@nasa.gov
NSF [AST-0908010, AST-0908040]; NCN [DEC-2011/01/B/ST9/03183,
DEC-2012/04/A/ST9/00083]; Taiwan National Science Council [NSC
100-2112-M-007-022-MY3]; National Science Foundation [PHY05-51164];
[NASA-NNG05GK73G]; [NNX07AJ88G]; [NNX08AG83G]; [NNX08 AL39G];
[NNX09AD16G]; [NNX12AH06G]
Ken-Ichi Nishikawa
P. Hardee
B. Zhang
I. Dutan
M. Medvedev
E. J. Choi
K. W. Min
J. Niemiec
Y. Mizuno
Ake Nordlund
Jacob Trier Frederiksen
H. Sol
Martin Pohl
D. H. Hartmann
eng
uncontrolled
Solar physics
eng
uncontrolled
astrophysics
eng
uncontrolled
astronomy (Energetic particles)
Institut für Physik und Astronomie
Referiert
Open Access
44685
2016
2016
eng
9
4
article
MDPI
Basel
1
--
--
--
Microscopic Processes in Global Relativistic Jets Containing Helical Magnetic Fields
In the study of relativistic jets one of the key open questions is their interaction with the environment on the microscopic level. Here, we study the initial evolution of both electron-proton (e(-)-p(+)) and electron-positron (e(+/-)) relativistic jets containing helical magnetic fields, focusing on their interaction with an ambient plasma. We have performed simulations of "global" jets containing helical magnetic fields in order to examine how helical magnetic fields affect kinetic instabilities such as the Weibel instability, the kinetic Kelvin-Helmholtz instability (kKHI) and the Mushroom instability (MI). In our initial simulation study these kinetic instabilities are suppressed and new types of instabilities can grow. In the e(-)-p(+) jet simulation a recollimation-like instability occurs and jet electrons are strongly perturbed. In the e(+/-) jet simulation a recollimation-like instability occurs at early times followed by a kinetic instability and the general structure is similar to a simulation without helical magnetic field. Simulations using much larger systems are required in order to thoroughly follow the evolution of global jets containing helical magnetic fields.
Galaxies : open access journal
10.3390/galaxies4040038
2075-4434
wos2016:2019
38
WOS:000391004000006
Nishikawa, KI (reprint author), Univ Alabama Huntsville, Dept Phys, ZP12, Huntsville, AL 35899 USA., ken-ichi.nishikawa@nasa.gov; mizuno@th.physik.uni-frankfurt.de; Jacek.Niemiec@ifj.edu.pl; oleh.kobzar@ifj.edu.pl; pohlmadq@gmail.com; jlgomez@iaa.csic.es; ioana.dutan@gmail.com; a.peer@ucc.ie; trier@nbi.ku.dk; aake@nbi.dk; ameli@ulg.ac.be; helene.sol@obspm.fr; pehardee@gmail.com; hdieter@g.clemson.edu
NSF [AST-0908010, AST-0908040, NASA-NNX09AD16G, NNX12AH06G, NNX13AP-21G, NNX13AP14G]; Narodowe Centrum Nauki [DEC-2013/10/E/ST9/00662]; ERC [610058]; Deutsche Forschungsgemeinschaft [PO 1508/1-2]; National Science Foundation [PHY05-51164]
importub
2020-03-22T12:15:01+00:00
filename=package.tar
dbb4140a488fb32b6e189c4175776678
Ken-Ichi Nishikawa
Yosuke Mizuno
Jacek Niemiec
Oleh Kobzar
Martin Pohl
Jose L. Gomez
Ioana Dutan
Jacob Trier Frederiksen
Ake Nordlund
Athina Meli
Helene Sol
Philip E. Hardee
Dieter H. Hartmann
eng
uncontrolled
relativistic jets
eng
uncontrolled
particle-in-cell simulations
eng
uncontrolled
global jets
eng
uncontrolled
helical magnetic fields
eng
uncontrolled
kinetic instabilities
eng
uncontrolled
kink instability
Institut für Physik und Astronomie
Referiert
Import
40760
2016
2018
eng
9
postprint
1
2018-06-27
2018-06-27
--
Microscopic processes in global relativistic jets containing helical magnetic fields
In the study of relativistic jets one of the key open questions is their interaction with the environment on the microscopic level. Here, we study the initial evolution of both electron-proton (e(-)-p(+)) and electron-positron (e(+/-)) relativistic jets containing helical magnetic fields, focusing on their interaction with an ambient plasma. We have performed simulations of "global" jets containing helical magnetic fields in order to examine how helical magnetic fields affect kinetic instabilities such as the Weibel instability, the kinetic Kelvin-Helmholtz instability (kKHI) and the Mushroom instability (MI). In our initial simulation study these kinetic instabilities are suppressed and new types of instabilities can grow. In the e(-)-p(+) jet simulation a recollimation-like instability occurs and jet electrons are strongly perturbed. In the e(+/-) jet simulation a recollimation-like instability occurs at early times followed by a kinetic instability and the general structure is similar to a simulation without helical magnetic field. Simulations using much larger systems are required in order to thoroughly follow the evolution of global jets containing helical magnetic fields.
Galaxies
urn:nbn:de:kobv:517-opus4-407604
online registration
MDPI Galaxies (2016), Vol. 4(38); DOI: 10.3390/galaxies4040038
CC-BY - Namensnennung 4.0 International
Ken-Ichi Nishikawa
Yosuke Mizuno
Jacek Niemiec
Oleh Kobzar
Martin Pohl
Jose L. Gómez
Ioana Duţan
Asaf Pe’er
Jacob Trier Frederiksen
Åke Nordlund
Athina Meli
Helene Sol
Philip E. Hardee
Dieter H. Hartmann
Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
446
eng
uncontrolled
relativistic jets
eng
uncontrolled
particle-in-cell simulations
eng
uncontrolled
global jets
eng
uncontrolled
helical magnetic fields
eng
uncontrolled
kinetic instabilities
eng
uncontrolled
kink instability
Astronomie und zugeordnete Wissenschaften
open_access
Mathematisch-Naturwissenschaftliche Fakultät
Institut für Physik und Astronomie
Referiert
Open Access
Multidisciplinary Digital Publishing Institute (MDPI)
Universität Potsdam
https://publishup.uni-potsdam.de/files/40760/pmnr_446.online.pdf
46128
2017
2017
eng
7
5
article
MDPI
Basel
1
--
--
--
Microscopic Processes in Global Relativistic Jets Containing Helical Magnetic Fields: Dependence on Jet Radius
In this study, we investigate the interaction of jets with their environment at a microscopic level, which is a key open question in the study of relativistic jets. Using small simulation systems during past research, we initially studied the evolution of both electron-proton and electron-positron relativistic jets containing helical magnetic fields, by focusing on their interactions with an ambient plasma. Here, using larger jet radii, we have performed simulations of global jets containing helical magnetic fields in order to examine how helical magnetic fields affect kinetic instabilities, such as the Weibel instability, the kinetic Kelvin-Helmholtz instability (kKHI) and the mushroom instability (MI). We found that the evolution of global jets strongly depends on the size of the jet radius. For example, phase bunching of jet electrons, in particular in the electron-proton jet, is mixed with a larger jet radius as a result of the more complicated structures of magnetic fields with excited kinetic instabilities. In our simulation, these kinetic instabilities led to new types of instabilities in global jets. In the electron-proton jet simulation, a modified recollimation occurred, and jet electrons were strongly perturbed. In the electron-positron jet simulation, mixed kinetic instabilities occurred early, followed by a turbulence-like structure. Simulations using much larger (and longer) systems are required in order to further thoroughly investigate the evolution of global jets containing helical magnetic fields.
Galaxies : open access journal
10.3390/galaxies5040058
2075-4434
wos:2017
58
WOS:000419211800003
Nishikawa, KI (reprint author), Univ Alabama, Dept Phys, ZP12, Huntsville, AL 35899 USA., ken-ichi.nishikawa@nasa.gov; mizuno@th.physik.uni-frankfurt.de; jlgomez@iaa.csic.es; ioana.dutan@gmail.com; ameli@ulg.ac.be; cmw0037@uah.edu; Jacek.Niemiec@ifj.edu.pl; oleh.kobzar@ifj.edu.pl; pohlmadq@gmail.com; a.peer@ucc.ie; jacob.trier@innofactor.com; aake@nbi.dk; helene.sol@obspm.fr; pehardee@gmail.com; hdieter@g.clemson.edu
NSF [AST-0908010, AST-0908040, NASA-NNX09AD16G, NNX12AH06G, NNX13AP-21G, NNX13AP14G]; ERC Synergy Grant [610058]; Deutsche Forschungsgemeinschaft [PO 1508/1-2]; NSF; National Science Foundation [PHY05-51164]
importub
2020-04-19T22:53:01+00:00
filename=package.tar
e978495d4299f9071070516b9ce0a214
Ken-Ichi Nishikawa
Yosuke Mizuno
Jose L. Gomez
Ioana Dutan
Athina Meli
Charley White
Jacek Niemiec
Oleh Kobzar
Martin Pohl
Jacob Trier Frederiksen
Ake Nordlund
Helene Sol
Philip E. Hardee
Dieter H. Hartmann
eng
uncontrolled
relativistic jets
eng
uncontrolled
particle-in-cell simulations
eng
uncontrolled
global jets
eng
uncontrolled
helical magnetic fields
eng
uncontrolled
kinetic instabilities
eng
uncontrolled
kink-like instability
eng
uncontrolled
recollimation shocks
eng
uncontrolled
polarized radiation
Institut für Physik und Astronomie
Referiert
Import