First annual OSIRIS Users and Developers Workshop

UCLA Particle-in-Cell and Kinetic Simulation Center and the
IST Extreme Plasma Physics Team in Portugal are pleased to announce
the first annual OSIRIS Users and Developers Workshop,
to be held at UCLA on September 18-20 2017.

The first annual OSIRIS Users and Developers Workshop is open
to all who have gained access to or are interested in gaining access
to the OSIRIS source code.

ACCELERATES featured in National TV show aired
during 2013 and 2014

The project ACCELERATES has been highlighted in the tv show 100 segundos de
ciência/100 seconds of science in a short documentary (100 seconds of duration)
describing the project and aired several times in prime time in 2013 and 2014.

Propagation of quasi-neutral beam into plasma

Propagation of a quasi-neutral fireball beam into plasma.
The region where electrons and positrons overlap perfectly shows
a filamentary structure, but as the beam propagates and charge
separation become relevant, wake-fields effects start to appear
with electrons blowed out and positrons sucked in.

Magnetized Current Filaments:
Evolution and single particle dynamics

The movie depicts the growth and evolution of transverse magnetic field
perturbation via Weibel Instability in a relativistic magnetized interpenetrating
electron proton plasma flow. The magnetic field energy is shown by
isosurfaces with their height being proportional to the magnitude.
The spheres represent plasma electrons and their colour scheme
represent their energies. Tracks of 64 randomly selected electrons
are shown to describe the motion of electrons at the single particle level.
The results show that for magnetized plasmas, the electrons at the edge
of the filament attain a net rotation due to EXB drift. .

Populating pulsar magnetospheres via QED cascades

Electron-positron plasmas can be formed around massive astronomical objects
(e.g. neutron stars) due to quantum electrodynamical (QED) effects.
This movie shows a QED-PIC simulation of the formation process of an
electron-positron cascade in an ultra intense (~10¹² G), curved magnetic field,
where ~10³ pairs and ~10⁵ photons are created from each initial electron.

Plasma lenses are not for positrons

Although appealing, plasma lensing is not suitable to focus relativistic positron beams.
The positron bullet (red) is launched in an under-dense plasma lens (grey),
its own wake  produces an inhomogeneous focus of the beam on axis.
After a certain distance travelled the positron bullet explodes as some particles
of the bunch defocus while the remaining are still in the focusing phase.

High orbital angular momentum harmonics generation

High harmonic generation (HHG) results from nonlinear optical processes,
and leads to a strong laser frequency upshift. An analogous process
can lead to the generation of high angular momentum (OAM) harmonics.

The picture shows the electric field structures of intense lasers
with high OAM harmonics. The lobes indicate the presence of the high
OAM harmonics. The propagation direction is shown by the grey arrows.

Magnetic vortex in astrophysics collisionless accretion disk

The figure shows magnetic field vortex structures in a 2D simulation of plasma in a
collisionless accretion disk. The simulation, obtained with OSIRIS PIC code,
shows the space distribution for the magnetic field along the radial
and vertical directions. 
These vortexes appear at the surface of change of sign
(red/orange positive-blue/green negative) of the magnetic field and are essential
for the activation of parasitic instabilities which trigger a turbulent plasma regime.

Fast electrons gain energy both
from the driving laser and its wake

Plasma based accelerators are promising alternatives to standard RF,
limited by structural breakdown, technologies. In the picture a laser pulse
(red) propagates trough a plasma (black) generating a wake of
electron density oscillations (higher density in blue) with trapped
electrons (green) that are accelerated in the wakefields indirectly
by the laser) and the laser fields (direct). A single electron (red color
scale) trajectory shows its energy growth from its origin, the laser front.

Large scale PIC simulation of high
beta magnetorotational instability

Evolution of the out-of-plane magnetic field in a 2D simulation of a
collisionless pair plasma accretion disk, from a seed of uniform
magnetic field to a comparison of a 2D turbulent regime.