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Numerical simulations of energy transfer in counter-streaming plasmas

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Submitted on 16 Jun 2016

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Numerical simulations of energy transfer in counter-streaming plasmas

M Hadj-Bachir, R Capdessus, Vladimir Tikhonchuk, Emmanuel d’Humìères

To cite this version:

M Hadj-Bachir, R Capdessus, Vladimir Tikhonchuk, Emmanuel d’Humìères. Numerical simulations of energy transfer in counter-streaming plasmas. Summer school in the frame of ERASMUS IP “An Introduction to high power light-matter interactions (HIPOLIN 2013)”, Jul 2013, Crete Greece. �hal-01332843�

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Youth, Family, and Contextual Characteristics Predicting Violence Exposure: Disruptive Behavior

Disorder Symptoms as a Moderator

Penny S. Loosier, Michael Windle, & Eun Young Mun

The University of Alabama at Birmingham

Numerical simulations of energy transfer in counter-streaming plasmas

M. HADJ-BACHIR

Supervisors: R. CAPDESSUS, E. d’HUMMIERES,

V. T. TIKHONCHUK

Univ.Bordeaux, CEA, CNRS , CELIA, 33405 Talence France.

Email: hadjbachir@celia.u-bordeaux1.fr

Introduction

Modeling shocks in astrophysical laboratories

Distribution functions of the electrons.

Asymetric case 10 keV / 100 eV

Colliding plasmas in universe.

PIC simulations of sub-relativistic plasmas

We present here an analysis of a very large PIC simulations of two inter-penetrating plasmas at sub-relativistic velocities. At the initial time moment in the center-of-mass

reference frame two homogenous plasmas of the density are facing each other in the simulation plane (x,y).

All lengths are measured in terms of electron inertia length, , the time is in inverse electron plasma frequencies, , the energy is measured in units of electron

rest energy, ,the electric and magnetic fields is are in relativistic plasma units, , and , respectively.

An experiment for studying the collisionnelss mechanism

of fast ion energy in laboratory plasma is proposed. We

have performed two dimensional PIC simulations of

electron-ion sub-relativistic counter-streaming plasma

beams propagating without an external magnetic field.

Electron heating is an important stage of shock formation.

This is probably due to stochastic processes that occurs

due to the strong charge separation. Radiation emission

losses is due to electron synchrotron emission [7].

Simulations of similar physical processes at the GRB scale

are ongoing.

Evolution of filaments

Conclusion

Scheme of laboratory experiment on the collisionless

dissipation of fast ion beams [1].

1_ A proton bunch is created from a thin foil irradiated by a high intensity short laser pulse.

2_ Transport zone of the proton bunch to the interaction site.

3_ Target plasma created by ionization of a gas jet with an auxiliary laser beam.

4_ Diagnostic equipments : ion energy detector, interferometer x-ray detector.

Ejecta from the central explosion : hot plasma.

Interaction with the ISM cold plasma.

Relativstic factor of the jet

g

= 100

explains the short

pulse duration recorded by observers [2],[4].

Major hypothesis

_Transformation of

the directed energy

into thermal energy.

_ Compton and

synchrotron

emission provides

a radiation cooling

of plasma [2].

Hot plasma jet

10keV representing the particles of the

core engine. Cold plasma 100 eV representing the ISM

c

u

p

0

.

2

c

u

p

0

.

2

3 18 0 10    cm n c m eE E pe e  ~ 2 c me 1  p ep e c / pe e m eB B~ 

Temporal development of inter-penetrating plasmas

First stage of interaction

electron instability [2],[3]

Second stage of interaction

Ion-electron instability [2],[3]

The electron vortex is attached to the edge of the hot plasma and

increases in size. Electron mixing and heating in parallel

direction stabilizes the two-stream instability but excites the Weibel

instability in the

transverse direction.

The caracteristic field is defined by the relative

electron-ion motion [2],[3] Propagation direction x. 110 * pet  110 * pet  110 * pet  110 * pet  0 0,2 0,4 0,6 0,8 t*Wpe 20 40 60 80 100 120 Max Ex Max Ey Max Bz 110 * pet  80 * pet  20 * pet

The sequence of instability can be seen in the temporal evolution of the fields.

The electron two-stream instability develops in the time scale The filamentation develops in the scale at

1 ) 20 , 10 ( pe 1 ) 100 , 86 ( pe c u c m eE u k m m p e e x p e x i e p e 6 . 0 3 / 1             g

Energy transfer in

the transverse

direction and

heating of electron.

Weibel instability

leads to electron

heating in the

transverse

direction.

110 * pet  96 * pet  96 * pet  80 * pet  110 * pet

Ions phase space _ time evolution over longer time scale

Mass ration of electrons

The ion motion starts on a longer time scale, and

they lose 10% of their energy at 84 . 42   e i pi pe m m   pi  200 400 * pet  8400 * pet  4000 * pett*pe  8400 6000 * pet  0 0,2 0,4 0,6 0,8 1 1,2 t*Wpe 0 2 000 4 000 6 000 8 000 1e+04 Max Ex Max Ey Max Bz

Distribution functions of the electrons.

Symetric case: two cold plasmas 100 eV.

Ions distribution functions

The ion streams are mixing

creating and modifing the electric

fields in the interaction zone.

The filament merges and are

drawn in transverse direction.

The lifetime of a filament is

1 1

800

20

pi pe

t

References

[1] Davis S., Tikhonchuk V., E d'Humieres E., and Weber S., "Proton beam Weibel

instability simulations of energy transfer in gamma-ray bursts,\ Journ. Physics: Conf. Series 244, 04206 (2010).

[2] V. Tikhonchuk.,R. Capdessus , E.d'Humieres ., S.Jequier , and S.P Davis.,’’ Energy transfer in couter-propagating plasmas at sub-relativistic velocities.\ Proceeding Prague (2013).

[3] Davis S. P., Capdessus R., d'Humieres E., Jequier S., Andriyash I., and Tikhonchuk V., "Numerical simulations of energy transfer in counter-streaming plasmas,\ High Energy Density Phys. 9, 213 (2012).

[4] Spitkovsky A., "On the structure is relativistic collisionless shocks in electron-ion plasmas,\ Astrophys.Journ. 673, L39 (2008).

[5] Martins S. F., Fonseca R. A., Silva L. O., and Mori W. B., "Ion dynamics and acceleration in relativistic shocks,\ Astrophys. Journ. 695, L189 (2009).

[6] Sentoku Y. and Kemp A. J., "Numerical methods for particle simulations at extreme densities and temperatures: Weighted particles, relativistic collisions and reduced

currents,\ Journ. Comput. Phys. 227, 6846 (2008).

[7] V. Medvedev Radiation of in Weibel-generted fields: a general case,\ arXiv:0906.1090v1 [astro-ph.HE]5 jun 2009.

Very high energy of electrons in the filament.

Strong electrostatic field due to the charge separation.

400

*

pe

t

t

*

pe

1200

2000

*

pe

t

Collisionless shocks are frequent events in the universe.

They transform energy of star explosion into hot plasma,

high energy particules and radiation. It has been shown

that the Weibel instability is a very good candidate to

explain GRBs [7]. We demonstrate with particule-in-cell

simulations that a part of directed kinetic energy of proton

beams is converted into energy of electron, ions, electric

and magnetic fields [1]. We study the shock structure and

energetics of flow and we demonstrate that electron

heating is an important catalyst to shock formation via

filamentation instability [3], [4].

We use the 2D version of PICLS.

For these kind of numerical simulation we use at least :160 cores, 14500 *1600 cells of plasma , 32 of macro-particules per cell.

the time step is .Time computation is typically 2 weeks.

0 * petEy Bz e

n

e x

cm

p

cm

p

xe c xp e e y cm P Py cme Py cme e y cm P Py cme e x

cm

p

e x

cm

p

The electric field

amplitude decreases . magnetique field

becomes dominant with the time.

Ions are stopped on higer scale of time.

e x

cm

p

e x

cm

p

e x

cm

p

e x

cm

p

e x

cm

p

e y cm P Py cme c xp e xp e c c xp e p e c xyp e c c yp e c yp e e x

cm

p

c xp e c x

p e pe t  0.1e x

cm

p

e x

cm

p

e x

cm

p

c xp e xp e c c xp e

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