Considered laser-target design: (a) spherical nanotarget/cluster, (b) ultrathin overdense foil, (c) preformed plasma, and (d) ultrathin foil with oblique laser incidence. The laser beam, which propagates from left to right and has the polarization plane , is schematically shown as a shaded region between the two hyperbolic surfaces on each panel. The laser best focus position coincides with the origins in the figures.
component of the focused plane wave (solid line) and focused Gaussian beam (dashed line) in the focal plane of the mirror.
(a) Electron jet moving out from the Coulomb-exploding ion core after interaction between the laser and a spherical plasma target. Here, a projection of the 3D distribution of electrons and ions onto the plane is shown for 33 fs after the pulse maximum reached the cluster. The laser is focused onto the origin. The initial position of the target center is . The curve at the bottom of the figure shows the position of the Gaussian envelope at this moment of time. (b) Average electron energies (solid line bars) and number of particles (dashed line bars) in the bunches for the instant corresponding to panel (a) vs the time delay of the pulse maximum with respect to the bunches; estimation for the particles number per bunch given by Eq. (5) (open squares). The inset shows the spectrum of the electrons in the last (most energetic) bunch.
(a) Longitudinal (solid line) and transversal (dashed line) electric field components of the laser in the vicinity of the top of the pulse. (b) Energy evolutions of the test particles started at different moments within the pulse. (c) The scheme showing how the bunch length is estimated.
Particles dynamics. (a) Time evolution of the particle energy. (b) Local laser phase seen by the particle. (c) Forces acting onto the particle in radial and transversal directions in the laboratory coordinate system. (d) Particle trajectory in plane.
Dynamics of particle motion in 1D model described by Eq. (9). (a) Time evolution of the particle energy. (b) Local field phase seen by the particle.
A snapshot of particles accelerated by the plane wave (a) and a Gaussian beam (b), incident onto an parabolic mirror. Only electrons with are shown. The foil position is given by .
Angular distributions of the electrons accelerated by a laser beam focused by an (a) , (b) , and (c) parabolic mirrors. Solid line: focused plane wave, . Dotted line: focused Gaussian beam, . Dashed line: focused plane wave, (for ), (for ), and (for ).
Spectra of electrons moving inside the solid angle in the direction of the maximum density of the electron jet: (a) 120 TW laser, 100 nm foil, various -numbers, and types of laser pulses incident onto the focusing mirror. (b) Plane wave beam incident onto the -mirror, various foil thickness or laser power. (c) 120 TW plane wave focused by an -mirror, 100 nm foil pre-expanded to various thicknesses.
(a) Plasma charge density, in units of , in the plane of plasma for 30° -polarized laser incidence. (b) Electrons spectra in the solid angle in the direction of the maximum density of the electron jet for different laser incidence angles and -polarization.
Article metrics loading...
Full text loading...