Speaker
Ms
Marta D'Angelo
(Gran Sasso Science Institute - INFN)
Description
Electron-positron pair plasmas are believed to play a role in a wide range of cosmic ray sources, including for example relativistic jets from Active Galactic Nuclei or wind outflows in Pulsar Wind Nebulae. One of the key points to understand cosmic ray acceleration is the generation of turbulent magnetic field near the shock front via plasma instabilities. In this work we investigate the development of the filamentation instability in counter-streaming pair plasmas, using particle-in-cell simulations (PIC) in both one and two spatial dimensions. Radiation friction effects on particles are taken into account. After an exponential growth of both the magnetic field and the current density, a nonlinear quasi-stationary phase sets up. This phase is characterized by filaments of opposite currents. During the nonlinear stage, a strong broadening of the energy spectrum occurs accompanied by the formation of a peak at twice the initial energy of the particles. A simple theory of peak formation is presented.
Primary author
Ms
Marta D'Angelo
(Gran Sasso Science Institute - INFN)
Co-authors
Dr
Andrea Macchi
(Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche (CNR/INO), u.o.s. Adriano Gozzini)
Dr
Andrea Sgattoni
(Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche (CNR/INO), u.o.s. Adriano Gozzini, Pisa)
Prof.
Francesco Pegoraro
(Dipartimento di Fisica Enrico Fermi, Universit\`a di Pisa)
Mr
Luca Fedeli
(Dipartimento di Fisica Enrico Fermi, Universit\`a di Pisa)
