All optical control of the topology of plasma accelerators

The picture shows simulation results illustrating a new type of plasma wave
that carries a novel topology, the orbital angular momentum,
which leads to spiraling electric field structures in the plasma (blue-red colours).
This plasma wave is driven by an intense laser pulse characterised by an helical
intensity profile, also known as a light spring (gree-yellow-red colours).
The plasma wave can accelerate a vortex electron bunch (blue-green spheres).

Energetic electrons in bow shock turbulence

Collisionless shocks and turbulent plasma regions are often
found in space and astrophysical magnetized plasma-obstacle interactions. 
Under common conditions in these plasmas, lower-hybrid waves can be excited,
leading to electron acceleration. This figure depicts the electrons (spheres)
acceleration process in the magnetic field (lines in orange-red) of a dipolar object
through the waves generated on the shock front (wavy line pattern).

Electrons surf the pipe!

Intense laser propagates through a light-pipe, trapping electrons on its way.
The pipe represents a region of low-density plasma within a high-density
background (a channel). Due to defocusing, without the channel,
the laser could not maintain the high intensity for a long propagation
distance. In the light-pipe, trapped electrons almost instantly
become relativistic and start co-propagating with the laser.
They can accelerate to over 10 GeV in a few millimetres.

Plasma density down-ramp: a way to control the
reproducibility of self-injected beams in LWFA

The picture shows the moment in that an electron beam is injected
in the wake by passing through a plasma density down-ramp.
The wake phase velocity depends on the local plasma density
and it is slowed down while passes by the negative density gradient.
Some of the energetic electrons at the rear of the bubble are
injected in the wake and will be accelerated by the field of the wake.

Monoenergetic ion beam from
improved laser-induced magnetic vortex

High quality ion beam can potentially be used for wide-ranging fields.
The advent of ultra-hight intensity laser provides access to laboratory-sized
compact ion accelerator via the intense accelerating fields in the laser-plasma
interactions. Magnetic vortex acceleration (MVA) is proposed to produce
collimated energetic ion beams in near-critical/underdense plasmas.

The picture shows the generation of a collimated ion beam (moving upward
along the vertical axis of the picture) when a relativistic laser is incident into
an underdense plasma. We proposed in our research an advanced target
design in which the underdense plasma is contained within an overdense tube.
In such integrated targets, the ion beam quality is much improved.

Beam compression by a blowout
wakefield in a beam ionized plasma

The video shows an electron beam propagating in an initially neutral gas
with a half-Gaussian longitudinal density profile, going from zero to its maximum
value for the duration of the video. The beam front starts to ionize the gas and the
tail of the beam is inside the excited wake. The beam density increases in the tail
as it starts to compress due to the transverse focusing force inside the wake
in the blowout regime.

Relativistic Magnetic Reconnection:
Magnetic Flux Tubes and Kinks in the Current Sheet

In extreme astrophysical environments, where plasmas are composed
of electron positron pairs, intense magnetic fields reconnect, which
heats the plasma and generates flows approaching the speed of light.
Oppositely directed magnetic fields are separated by a current sheet
shown in red. The current sheet kinks, shown initially, pinches into x-points
where the magnetic flux reconnects, and forms flux tubes out of the
reconnected plasma in the center of the current sheet, shown at the end.

Kinking twin beams

One positron beam (red) and one electron beam (green) propagate along
the horizontal axis and collide with a transverse misalignment.
The video shows the evolution of their density as disruption, QED pair
production and kink unstable modes come into play all together.
Each beam pinches under the action of the disruption effect and oscillates
transversely due to the kink instability. Furthermore, the beam density shows
ripples as a result of the stochasticity of the QED processes.

Exploring the onset of oblique instability
in realistic finite beam-plasma system

The picture depicts two dimensions cylindrical PIC-simulation,
visualized in three dimensions, of a long fireball beam (at 20 cm)
interacting with a static plasma composed of e− and e+.
The development of oblique instability is observed due to the
coupling between longitudinal and transverse modes.