July 29, 2015 to August 6, 2015
World Forum
Europe/Amsterdam timezone

ELECTRON HEATING IN A RELATIVISTIC, WEIBEL-UNSTABLE PLASMA

Aug 4, 2015, 4:00 PM
1h
Amazon Foyer (World Forum)

Amazon Foyer

World Forum

Churchillplein 10 2517 JW Den Haag The Netherlands
Board: 181
Poster contribution CR-TH Poster 3 CR

Speaker

Rahul Kumar (Ben Gurion University)

Description

The dynamics of two initially unmagnetized relativistic counter-streaming homogeneous ion-electron plasma beams are simulated in two dimensions using the particle-in-cell (PIC) method. It is shown that current laments, which form due to the Weibel instability, develop a large scale longitudinal electric eld in the direction opposite to the current carried by the laments as predicted by theory. This eld, which is partially inductive and partially electrostatic, is identied as the main source of net electron acceleration, greatly exceeding that due to magnetic eld decay at later stages. The transverse electric eld, though larger than the longitudinal one, is shown to play a smaller role in heating electrons, contrary to previous claims. It is found that, in 1D, the electrons become strongly magnetized and are not accelerated beyond their initial kinetic energy. Rather, the heating of the electrons is enhanced by the bending and break-up of the laments, which releases electrons that would otherwise be trapped within a single lament and slow the development of the Weibel instability (i.e. the magnetic eld growth) via induction as per Lenz's law. In 2D simulations electrons are heated to about one quarter of the initial kinetic energy of ions. The magnetic energy at maximum is about 4 percent, decaying to less than 1 percent by the end of the simulation. The ions are found to gradually decelerate until the end of the simulation by which time they retain a residual anisotropy less than 10 percent.
Registration number following "ICRC2015-I/" 168
Collaboration -- not specified --

Primary author

Rahul Kumar (Ben Gurion University)

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