ﻻ يوجد ملخص باللغة العربية
A new type of proton acceleration stemming from large-scale gradients, low-density targets, irradiated by an intense near-infrared laser is observed. The produced protons are characterized by high-energies (with a broad spectrum), are emitted in a very directional manner, and the process is associated to relaxed laser (no need for high-contrast) and target (no need for ultra-thin or expensive targets) constraints. As such, this process appears quite effective compared to the standard and commonly used Target Normal Sheath Acceleration technique (TNSA), or more exploratory mechanisms like Radiation Pressure Acceleration (RPA). The data are underpinned by 3D numerical simulations which suggest that in these conditions Low Density Collisionless Shock Acceleration (LDCSA) is at play, which combines an initial Collisionless Shock Acceleration (CSA) to a boost procured by a TNSA-like sheath field in the downward density ramp of the target, which leads to an overall broad spectrum. Experiments performed at 10^20 W/cm^2 laser intensity show that LDCSA can accelerate, from ~1% critical density, mm-scale targets, up to 5x10^9 protons/MeV/sr/J with energies up to 45(+/- 5) MeV in a collimated (~6$^circ$ half-angle) manner.
Magnetic reconnection is a fundamental plasma process that is thought to play a key role in the production of nonthermal particles associated with explosive phenomena in space physics and astrophysics. Experiments at high-energy-density facilities ar
Relativistic temperature electrons higher than 0.5 MeV are generated typically with laser intensities of about 10$^{18}$ W/cm$^{2}$. Their generation with high repetition rate lasers that operate at non-relativistic intensities ($simeq$10$^{16}$ W/cm
Observations of the interaction of an intense {lambda}0 approx 10 {mu}m laser pulse with near-critical overdense plasmas (ne = 1.8 - 3 nc) are presented. For the first time, transverse optical probing is used to show a recession of the front surface
The radiation pressure acceleration (RPA) of charged particles has been considered a challenging task in laser particle acceleration. Laser-driven proton/ion acceleration has attracted considerable interests due to its underlying physics and potentia
It is shown that ions can be accelerated to MeV energy range in the direction perpendicular to the magnetic field by the ExB mechanism of electrostatic waves. The acceleration occurs in discrete steps of duration being a small fraction the gyroperiod