Group of Lasers and Plasmas

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.
Tightly focused positron beams drive a plasma hollow-channel

Different routes to accelerate positrons up to the energy frontier have long been explored,
nevertheless, they were not sufficiently efficient for future linear colliders requirements.
Driven by theadvantageous features that plasma wakefield acceleration configurations
have shown in accelerating electrons, we have developed a novel mechanism with
the self-generation of a plasma hollow channel (green) leading to optimal
accelerating and focusing wakefields for positron (yellow/blue) acceleration.
Generation of miniature magnetised shockwaves

By interacting with minimagnetospheres, super-alfvénic plasma streams
can generate collisionless shocks with very distinct features, like solitary
(tsunami-like) magnetosonic waves.  In the figure, we represent the magnetic field
of a train of solitary waves (in blue tones) resulting from the interaction with a
minimagnetosphere, whose typical size is of a few ion Larmor radii. In orange/red
tones, we represent the electron fluid velocity component perpendicular to the
magnetic field, that illustrates the development of electron-scale instabilities
at the magnetopause.
Twisted plasma waves with orbital angular momentum

Orbital Angular Momentum is a fundamental laser property leading
to spiralling laser wavefronts. These lasers have been leading to
discoveries in super-resolution microscopy, quantum computation or
ultra-fast optics communication.
Its potential to explore new kinds of laser plasma interactions with
applications in plasma based acceleration and compact radiation sources
may be tremendous. The image shows a laser pulse with orbital
angular momentum after propagating in a plasma.
Orbital angular momentum cascading
in stimulated Raman backscatering

Orbital Angular Momentum (OAM) is a fundamental laser property whose
potential to applications has just started to be unraveled. In addition to
discoveries in non-linear optical contexts, the interaction of these lasers
with plasmas has just started to be explored. The image shows a plasma wave
driven by OAM lasers that shows signatures of orbital angular momentum,
corresponding to spiralling plasma wave fronts. These features
may unleash new exciting laser-matter interaction discoveries.
Competition between self-modulation and hosing
instability in self-modulated wakefield acceleration

The expected beam plasma dynamics in a recently
proposed plasma acceleration experiment at CERN is shown.
The desired self-modulation instability (SMI), illustrated in the first
part of the animation, leads to the production of several particle
beamlets (colored yellow and orange) that generate large amplitude
plasma waves (colored blue and gray). The second part of the
movie shows SMI and hosing instability (HI) competition.
The HI wins in this case and leads to beam break up.
Brillouin amplification: towards
next generation laser energy densities

This animation illustrates efficient energy transfer from a long and
energetic pump to a short probe laser pulse via stimulated
Brillouin backscattering. It is shown that the probe pulse can be
amplified to to high intensities (15x pump intensity) while
preserving a smooth envelope. Pushing the interaction
further leads to probe filamentation, which destroys the
probe envelope and limits the amplification process.
Magnetic field generation: the Biermann battery in action

This movie depicts the expansion of a plasma and the generation of magnetic fields
via the Biermann battery. The contours are isosurfaces of the density which is
decreasing in the center as the plasma flows outward. Although the plasma does
not move significantly, the density gradient upward, and the temperature gradient
(not shown) pointing inward generate a clear toroidal magnetic field. It becomes
evident that this field is strong enough to slow down the upper plasma while the
plasma closer to the (z=0) surface continues to expand without constraint.
Filamentation of solid target due to interaction of a Laser

The interaction of high power laser pulses with solid target (n_e ~ 10²² cm⁻³)
generates hot energetic electrons. Some of electrons escape the target but
a large quantities of hot electrons reflexes back and causes the current
imbalance inside the target, leading to the growth of the Weibel Instability.
Here we show results from a 3D-simulation representing the development of
Weibel instability due to laser-target interaction. Such studies are important
in the context of laser-driven energy and as well in astrophysical objects.
An efficient light-matter-light converter

The QED cascades are characterized by the creation of a pair plasma
in a ultra intense laser field. The cascade is seeded by electrons that due
to the acceleration in the laser field produce hard photons who eventually
decay into electron-positron pairs.
When the density of the pair plasma created reaches the critical density,
a strong absorption of the laser might occur. The results show that at high
intensity, most of the laser energy has been converted into energetic photons.

ACCELERATES featured in National TV show aired
during 2013 and 2014

Tightly focused positron beams drive a plasma hollow-channel

Generation of miniature magnetised shockwaves

Twisted plasma waves with orbital angular momentum

Orbital angular momentum cascading
in stimulated Raman backscatering

Competition between self-modulation and hosing
instability in self-modulated wakefield acceleration

Brillouin amplification: towards
next generation laser energy densities

Magnetic field generation: the Biermann battery in action

Filamentation of solid target due to interaction of a Laser

An efficient light-matter-light converter

Latest News

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Latest Publications

ACCELERATES featured in National TV show aired during 2013 and 2014

Tightly focused positron beams drive a plasma hollow-channel

Generation of miniature magnetised shockwaves

Twisted plasma waves with orbital angular momentum

Orbital angular momentum cascading in stimulated Raman backscatering

Competition between self-modulation and hosing instability in self-modulated wakefield acceleration

Brillouin amplification: towardsnext generation laser energy densities

Magnetic field generation: the Biermann battery in action

Filamentation of solid target due to interaction of a Laser

An efficient light-matter-light converter

Latest News

GoLP post

Latest Publications

ACCELERATES featured in National TV show aired
during 2013 and 2014

Orbital angular momentum cascading
in stimulated Raman backscatering

Competition between self-modulation and hosing
instability in self-modulated wakefield acceleration

Brillouin amplification: towards
next generation laser energy densities