185 research outputs found
Ion acceleration in "dragging field" of a light-pressure-driven piston
We propose a new acceleration scheme that combines shock wave acceleration
(SWA) and light pressure acceleration (LPA). When a thin foil driven by light
pressure of an ultra-intense laser pulse propagates in underdense background
plasma, it serves as a shock-like piston, trapping and reflecting background
protons to ultra-high energies. Unlike in SWA, the piston velocity is not
limited by the Mach number and can be highly relativistic. Background protons
can be trapped and reflected forward by the enormous "dragging field" potential
behind the piston which is not employed in LPA. Our one- and two-dimensional
particle-in-cell simulations and analytical model both show that proton
energies of several tens to hundreds of GeV can be obtained, while the
achievable energy in simple LPA is below 10 GeV.Comment: submitte
Axionlike-particle generation by laser-plasma interaction
Axion, a hypothetical particle that is crucial to quantum chromodynamics and
dark matter theory, has not yet been found in any experiment. With the
improvement of laser technique, much stronger quasi-static electric and
magnetic fields can be created in laboratory using laser-plasma interaction. In
this article, we discuss the feasibility of axion or axionlike-particle's
exploring experiments using planar and cylindrically symmetric laser-plasma
fields as backgrounds while probing with an ultrafast superstrong optical laser
or x-ray free-electron laser with high photon number. Compared to classical
magnet design, the axion source in laser-plasma interaction trades the
accumulating length for the source's interacting strength. Besides, a
structured field in the plasma creates a tunable transverse profile of the
interaction and improves the signal-noise ratio via the mechanisms such as
phase-matching. The mass of axion discussed in this article ranges from 1
\textmu eV to 1 eV. Some simple schemes and estimations of axion production and
probe's polarization rotation are given, which reveals the possibility of
future laser-plasma axion source in laboratory.Comment: 24 pages, 5 figure
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